They always say time changes things – a comparative study of epibenthic assemblage in high Arctic fjord between 2005 and 2020

They always say time changes things – a comparative study of epibenthic assemblage in high Arctic fjord between 2005 and 2020 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article They always say time changes things – a comparative study of epibenthic assemblage in high Arctic fjord between 2005 and 2020 Anna Sowa, Piotr Balazy, Maciej Chelchowski, Maria Włodarska-Kowalczuk, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4389944/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Accelerated warming has been reported in the Arctic in recent years. Climate change forcing has been detected in many aspects of high-latitude ecosystem ecology. Given previous reports of shifts within the Arctic benthos, we anticipated changes when revisiting the structure of epibenthic assemblages colonising the shallow subtidal zone in Svalbard’s largest sill-less fjord, Isfjorden. To investigate that, experimental constructions holding replicate settlement plates (artificial substrata) were set up at two stations on the rocky bottom of southern Isfjorden in the summer of 2004 and were retrieved after a year of immersion. The same procedure was conducted again after 15 years, in summer 2019. The comparison of the samples from those two periods showed significant differences in assemblage structure. The most substantial change observed was a shift in species dominance suggesting a reorganisation of the assemblage. Most notable was a difference in the abundance of the typically Arctic bryozoan Harmeria scutulata (from 100 to 0 ind. per 100 cm 2 between 2005 and 2020), which before 2004 was found to account for more than 50% of bryozoan individuals encrusting stones around Svalbard. The overall taxonomic composition was, however, representative of West Spitsbergen. The Arctic, particularly the Eurasia sector, has been under sustained climate change forcing long prior to the establishment of our field experiment, thus even the 2005 results may showcase an epibenthic assemblage in an already altered state. We think this emphasises how important robust baseline data are to provide crucial reference points to measure and understand change. encrusters benthic colonisation subtidal Arctic atlantification artificial substrate field experiment Svalbard Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction Most of the Arctic has experienced sustained intense warming for decades with the pace of this change being up to fourfold faster compared with the global average (Rantanen et al. 2022 ). Shallow coastal areas, besides having highly unstable conditions (Balazy and Kuklinski, 2017 ; Beuchel et al. 2006 ), are especially exposed to climate change influences (Friedlander et al. 2023 ). The continued increase in temperature leads to growing calving and consequently, ice scour (Conlan and Kvitek, 2005 ). On the other hand, sea ice in the coastal areas acts as a buffer to erosion caused by storms. With its continuous decrease and growing intensity and frequency of storm activity the shores will be exposed to greater deterioration (Lantuit et al. 2011). With these changes superimposed over freshening, sea level rise and acidification, it is important to monitor the responses across ecosystems, rather than focus (as many studies do) on a few large, charismatic species. When it comes to the Arctic assemblages a main stumbling block for evaluation of the impacts of climate change is the lack of reliable baseline information (Wassmann et al. 2011 ). The Arctic has already been under the influence of ongoing and accelerating warming for about five decades probably leading to shifts in many ecosystem elements long before they become a focus of research studies (Friedlander et al. 2023 ). Therefore, it is crucial to fill that knowledge void to subsequently increase the interpretive power of future assessments, such as if the predictions of increasing range shift of boreal species are being realised (Renaud et al. 2015 ; Górska et al. 2022 ). In the Arctic, benthos encompasses over 90% of described marine fauna species (Evseeva et al. 2023). Many sessile taxa colonise the coastal regions, typically characterised by hard or mixed substrates (Dunlop et al. 2020). Benthic assemblages that predominantly lead a sedentary or sessile life in the subtidal are thought to be important indicators of environmental change (Evseeva et al. 2024; Jorda-Molina et al. 2023; Beuchel et al. 2006 ). Previous studies on benthic response to environmental forcing revealed that benthic groups can display delayed feedback due to consequent lags connected to altered diet, feeding rates and eventually the reproductive rates and/or success (Beuchel et al. 2006 ). This could be true when no direct influence on the sessile organism has been exerted (Gray and Christie, 1983 ). With stronger changes in the environment, responses of immobile (as adults) fauna could be more drastic, especially for species with narrow tolerances, for example to temperature (Renaud et al. 2019). It is expected that more species of boreal origin may shift range to the Arctic waters with regional warming, to maintain their ‘temperature envelope’ (Renaud et al. 2015 ; Górska et al. 2022 ). A flag example of this process is the return of the blue mussel ( Mytilus edulis ) in the Svalbard region (Berge et al. 2005; Kotwicki et al. 2021 ). Furthermore, several expansions of boreal species Calanus finmarchicus with the simultaneous retreat of Arctic species C . glacialis and C . hyperboreus (Dalpadado et al. 2012 ), as well as a northward shift of the stock of Atlantic cod and haddock (Fossheim et al. 2015 ; Renaud et al. 2012 ) into the Barents Sea region were reported since as early as 2004. Others have reported changes in the structure of algae assemblages, with a major dominance of Synechococcus in the Arctic waters where it had not been previously, commonly found (Paulsen et al. 2016 ). In the benthic realm, the expansion of Gammarus oceanicus has been observed to be coincident with warming of Spitsbergen shores (Weslawski et al. 2010 ). Likewise Górska et al. ( 2022 ) reported increased presence of cosmopolitan ( Maldane sarsi ) and arctic-boreal (e.g. Galathowanie oculata and Prionospio cirrifera ) polychaetes in the deep Fram Strait. In the intertidal of the eastern Kola Peninsula region, new records of a bryozoan have been reported – Valkeria uva , a species of boreal origin previously known from the area to the west of Kola Bay (Evseeva et al. 2022 ). In another study focusing on Franz Josef Land, Evseeva and Dvoretsky ( 2024 ) identified 22 new records of species in the study region, with 7 having boreal origins. In both cases, the establishment of the new records was attributed to the growing temperatures, although transport vectors have increased and many other stressors altered as well. As the Svalbard region is under intense influence of warm Atlantic waters carried by West Spitsbergen Current we expect to see severe changes in epibenthic assemblage dynamics there. Previous studies of the hard-bottom assemblages in the Arctic tend to focus on one-year snapshots (Kuklinski and Barnes, 2005 ; Barnes and Kuklinski, 2005 ; Voronkov et al. 2016 ; Evseeva et al. 2023) or seasonal aspects of recruitment (Kuklinski et al. 2013 ; Meyer et al. 2017 ; Sowa et al. 2023 ). One-year snapshots have allowed comparisons in macro space (Barnes, 2015 ) but rarely time (but see Watson and Barnes, 2004 ). A 2–3 year study in deeper water found little effect of a sampling year, but these were close together (2017-19, see Souster et al. 2024 ). Multi-year, long-term research by Beuchel et al. ( 2006 ), Beuchel and Gulliksen ( 2008 ) and Al-Habahbeh et al. ( 2020 ) at 79°N Kongsfjorden have yielded insight into succession processes on natural substrate over few decades. However, the taxonomic resolution of these studies was very different due to the samples being photographic images, which can lead to underreporting of taxonomic richness (Beisiegel et al. 2017 ). When attempting to evaluate the influence of long temporal-scale processes such as climate change on the biodiversity and structure of marine communities and detangling it from natural variability a meaningful baseline is crucial (Jorda-Molina et al. 2023; Chan et al. 2019 ; Wassmann et al. 2011 ; Beuchel et al. 2006 ). Nonetheless, the base information is often lacking especially in remote areas characterised by extreme conditions. Additional problems arise when dealing with the hard-bottom communities for which the experimental protocol is difficult without the engagement of SCUBA divers (Nicoletti et al. 2007 ; Renaud et al. 2007 ). The use of experimental constructions that can be removed from the environment at the end of the project and which have limited lasting influence on the natural ecosystem fit well with increasing attempts at employing less invasive means of studying the environment (Bowden et al. 2006 ; Kuklinski et al. 2022 ). The uniformity of such artificial substrata and associated methodology aids comparability of replicates and results (Barnes, 1996 ; Kennedy et al. 2017 ; Kuklinski et al. 2022 ). Furthermore, settlement plates made from black, homogenous plastic – HIPS (High Impact Polystyrene) have been used in many studies in the Arctic region and all supported settlement of zoo- and phytobenthos (e.g. Barnes and Kuklinski, 2005 ; Meyer et al. 2017 ; Sowa et al. 2023 ). Kennedy et al. ( 2017 ) showed that plastic materials can accurately approximate natural coralline algae assemblages. Given the intense climate forced changes already described in the Arctic, we hypothesise that epibenthic assemblages of the shallow coastal zone in Isfjorden would show compositional responses after 15 years. To measure any such assemblage changes our study aimed to 1) describe the structure of a subtidal, hard-bottom assemblage to provide baseline information, 2) repeat protocol at the same study location to reanalyse assemblages recovered after the same immersion period but after 15 years, 3) investigate the influence of two additional factors (‘site’ and ‘depth’) and 4) track any possible arrival of new species, especially of Atlantic origin. 2. Material & methods 2.1 Study area Isfjorden (78.33° N, 15.00° E) is the largest fjord of West Spitsbergen (Nilsen et al. 2008 ). It lacks a sill at the mouth, which allows the free inflow of two major water masses influencing this area. West Spitsbergen Current, carries Atlantic Water (Θ > 3°C, 35.1 < S A < 35.4 g/kg) and the extension of the Spitsbergen Polar Current, transports Arctic Water (Θ < 1°C, 34.5 < S A < 35 g/kg) from the Barents Sea region (Θ – conservative temperature, S A – absolute salinity; Fraser et al. 2018 ). The study period of field deployments spanned 2004–2005 and 2019–2020. Between these sample intervals, a distinct shift in environmental conditions was recorded in Isfjorden. Since the winter of 2006, a switch was detected from an Arctic Water state to an increased inflow of Atlantic Water, even in winter, with a subsequent decline in sea ice presence in the fjord (Cottier et al. 2007 ; Muckenhuber et al. 2016; Skogseth et al. 2020 ). The southern bank of Isfjorden also lacks any tidewater glaciers. Within the fjord, on the southern bank near Grumantbyen, two sites, S1 (78.21292°N, 15.23556° E) and S2 (78.1883° N, 15.1447° E) were visited and sampled at two depths (7 and 14 ± 1 m). The natural substrate there was mainly hard comprising of rocks and boulders with pockets of sand at both locations. The infralittoral (depth 10 m) was mostly barren (Balazy and Kuklinski, 2017 ). 2.2 Protocol The investigation into the benthic assemblage structure there was conducted using experimental constructions, which held exchangeable panels with three black settlement plates (replicates; 15 cm × 15 cm; High Impact Polystyrene). A full description of the constructions can be found in Kuklinski et al. ( 2022 ). The first settlement plates were submerged in the summer of 2004 and retrieved a year later in 2005. Another set of similar apparatus was submerged after 15 years in the summer of 2019 and collected in 2020. All fieldwork operations were conducted by the SCUBA divers from the IO PAN Scientific Diving Team. 2.3 Analysis The panel samples with colonists were analysed under a stereoscopic microscope Leica M205C with a focus on the central area of the plates (10 cm × 10 cm) to minimise ‘edge effect’ as recommended by Harris (1988). A specially designed frame with 1 cm x 1 cm grid was used to eliminate the plate's unrepresentative edge during the analysis. The encrusting fauna was identified morphologically to the lowest possible taxonomic level (Klekowski and Weslawski, 1991 ; Kluge, 1975 ; Rzhavsky et al. 2014 ) and counted. In case of colonial organisms, a colony was counted as a singular organism. Data preparation, statistical analysis and visualisation were performed using Microsoft Excel, Statistica software (StatSoft, Inc., 2007) and Primer v.7 (Clarke et al. 2008 ). Three-way PERMANOVA was used to test the differences in species richness, abundance and taxonomic composition on plates among three factors (year, site, depth; all fixed and with two levels each) and their interactions. Square root transformed data were used for this analyses. ANOSIM analysis was used to test for differences between abundances of selected species among the ‘year’ factor. For all further analysis, we used data averaged from three replicate plates. To test the structure of the assemblages we applied the LINKTREE analysis, which groups samples based on SIMPROF similarity profile tests. At each division level, a set of taxa that differentiated the samples was identified and cut-off values were given. The conditions that provided the best results were as follows: minimum group size = 1, minimum split size = 3, and minimum split R = 0.5. The shadeplot was prepared to show the relative abundances of all the identified taxa as well as a bar plot to display the most abundant taxa (chosen based on the mean number of individuals being equal or higher than 100 in any sample). Diversity indices were also calculated including Shannon–Wiener species diversity index (ln-based; H’) and Pielou evenness index (J’). 2.4 Temperature and sea ice To provide environmental background we obtained satellite data from the Isfjorden region for the time of the plate submersion. These data were provided by the Danish Meteorological Institute and the Copernicus CMEMS project (Original Dataset: cmems_obs_si_arc_phy_my_L4-DMIOI_P1D-m; Translation Date: 2022-10-03). The original data were averaged for every month for two periods: from July 2004 to July 2005 and from July 2019 to July 2020. From the dataset, Surface Temperature (which includes data recorded by satellite over water and ice surface) and Sea Ice Fraction (the fraction of the ocean covered with sea ice) were obtained. The geospatial coordinates limits used were 76.5° − 79.5° N and 10.97° − 17.47° E, with a resolution of 0.05°. All the operations on the data were performed using Python in the Google Colaboratory environment. 3. Results In total, over 20,000 individuals were identified on the 24 experimental settlement plates recovered from 7 and 14 ± 1 m, at two sites. The total abundance in 2005 (7547) and 2020 (13,111) differed by > 5000, while the means per plate (100 cm 2 ) were the equivalent to 1092.6 ± 350.4 (2005) and 628.9 ± 333.2 (2020). Overall, 47 taxa were identified to lowest possible taxonomic level (27 to species level) and represented three Phyla: Bryozoa (38 taxa), Annelida (7 taxa) and Arthropoda (2 taxa). In samples from 2005, we differentiated 39 taxa (18.4 ± 7.0 per 100 cm 2 ), compared with 42 (22.7 ± 3.3 per 100 cm 2 ) occurring on the plates in 2020 (Fig. 3 ). Environmental settings differed between two study periods. 2019/2020 was warmer than 2004/2005, especially during winter months (January to April). The biggest differences (13.88°C between average values) in March could be attributed to the presence of sea ice in the fjord that influenced the measurements of surface temperature over the Isfjorden area. Although Isfjorden has been largely ice-free since 2006 (Muckenhuber et al. 2016), ice was recorded during the winter of 2020. The Cheilostomata bryozoans Arctonula arctica , Callopora lata , Dendrobeania sp., Schizoporella obesa and other schizoporellids that appeared on the experimental plates in 2005 were not identified in 2020. Eight taxa were recorded only on the panels recovered in 2020 (not seen in 2005): Doryporella spathulifera , Diplosolen arctica , Tricellaria arctica , Tricellaria gracilis , Stomachetosella cruenta , Spirorbis tridentatus , a dark type of Tegella sp. and Scrupocellidae individuals. Datasets from both years had 34 taxa in common. In 2020 Harmeria scutulata (ANOSIM between years R = 0.44) and Semibalanus balanoides (R = 0.82) were less abundant, whilst cyclostome and cheilostome ancestrulae (R = 0.72 and 0.57 respectively), Microporella arctica (R = 0.54), Tegella arctica (R = 0.63), and Circeis sp. (R = 0.73) were more abundant than in 2005. In 2005, ancestrula of Cyclostomata (134.3 per 100 cm 2 ), S . balanoides (153.0 per 100 cm 2 ), Circeis sp. (125.3 per 100 cm 2 ) and P . vitrea (121.0 per 100 cm 2 ) were the most abundant at S1 7 m, while H . scutulata (100.0 per 100 cm 2 ), S . balanoides (157.3 per 100 cm 2 ), Circeis sp. (346.7 per 100 cm 2 ) and P . vitrea (130.0 per 100 cm 2 ) at S2 shallow. In 2020 at the shallow study sites, two taxa of the overall highest abundance (per 100 cm 2 ) were recorded; P . vitrea (502.0 per 100 cm 2 ) at S1 and Circeis sp. at (527.0 per 100 cm 2 ) at S2 (Fig. 4 ). Apart from S2 7 m, a significant increase in mean values of species richness and abundance per plate (Fig. 5 ; Table 3 ) in 2020 were observed at both stations, and depths. Species richness and abundance were the most variable at S1 (13 m) in 2020. The highest species richness was reached at the S2 shallow (7 m) station in 2005. The highest abundance was noted at S1 shallow in 2020. It was also at this station that the biggest difference (more than double) in total abundance between 2005 (693.7 per 100 cm 2 ) and 2020 (1545.7 per 100 cm 2 ) was observed. The sample from S2 at 15 m in 2005 had the lowest value of the Pielou (0.77) index (Table 2 ). Those replicates were highly dominated by S . balanoides individuals (Fig. 3 ; Fig. 4 ). Assemblages at the S2 at 7 m did not significantly differ between years aside from it all other pairs of site and depth were significantly different between years based on the Wilcoxon test (p > 0.05; Table 1 ). Samples from S1 (13 m) collected in 2020 reached the highest values of the Shannon - Wiener diversity index (3.03). Table 1 Results of the Wilcoxon paired test displaying differences between the taxonomic composition of samples from 2005 and 2020. Significant values in bold (p < 0.05) S1 2005 7m S1 2005 13m S2 2005 7m S2 2005 15m S1 2020 7m 0.01 0.00 0.82 0.00 S1 2020 13m 0.09 0.00 0.89 0.00 S2 2020 7m 0.02 0.00 0.65 0.00 S2 2020 15m 0.13 0.06 0.27 0.00 Table 2 Pielou’s (J’) and Shannon- Wiener’s diversity (H’) indices for averaged data from three replicate samples S1 S2 7m 13m 7m 15m 2005 2020 2005 2020 2005 2020 2005 2020 J’ 0.85 0.83 0.87 0.86 0.87 0.85 0.77 0.84 H’ 2.78 2.80 2.88 3.03 2.99 2.87 2.04 2.70 There were significant differences between 2005 and 2020 in species richness, abundance and assemblage structure based on the PERMANOVA analysis (Table 3 ). The ‘year’ was the most influential factor differentiating the structure of the assemblage (28.54%). Whereas for taxa richness and abundance the ‘depth’ factor described most of the variability between samples (19.85% and 30.12%, respectively) and for both of them ‘site’ was not statistically significant. Only in the case of assemblage structure did all of the study factors have a significant influence. Table 3 Three-way PERMANOVA analysis for differences among sites, years and depths based on species richness, abundance and assemblage structure. Raw data were square root transformed. Significant values mean p < 0.05 species richness abundance assemblage structure factors Pseudo-F p CV [%] Pseudo-F p CV [%] Pseudo-F p CV [%] site 0.99 0.389 0.00 0.22 0.737 1.58 4.88 0.000 4.33 year 6.78 0.010 12.12 13.02 0.001 24.24 26.58 0.000 28.54 depth 10.47 0.003 19.85 15.93 0.004 30.12 13.16 0.000 13.57 site x year 0.02 0.948 4.10 0.27 0.688 2.96 3.92 0.000 6.51 site x depth 4.88 0.038 16.26 0.05 0.917 3.83 6.40 0.001 12.05 year x depth 4.70 0.035 15.52 2.51 0.125 6.11 3.91 0.005 6.50 site x year x depth 0.17 0.746 6.99 1.86 0.164 6.95 4.39 0.001 15.12 The underlying structure of the epibenthic assemblage overgrowing the settlement plates was also investigated using LINKTREE analysis (Fig. 6 ). The splits in the cluster were based on the abundances of taxa differentiating the samples (cut-off values added in brackets). Two of the five splits were significant. The first split (A) was based on the levels of abundance of several taxa – Electra arctica (> 2.67 235 < 157), Tubuliporidae indet. ( 3.67), ancestrula Cyclostomatida ( 65.7), Circeis sp. ( 119), Callopora lineata ( 3.67), Spirorbinae indet. ( 9) or Spirorbis sp./ Bushiella sp./ Pilleolaria sp. complex ( 12.3), Circeis spirillum ( 2), Callopora sp. ( 2.33), P . vitrea ( 22.3), ancestrula Cheilostomatida ( 3.33) or Myriozella crustacea ( 0.667) and it differentiated sample from S2 (12 m) collected in 2005 from the remaining samples. The next significant split (B) differentiated two groups. This split was based on the abundance of a few taxa – Cylindroporella tubulosa ( 4.67), Spirorbinae indet. ( 33.7), ancestrula Cheilostomatida ( 17.7) or S . balanoides (> 51.7 < 15). Split C grouped the rest of the samples from 2005. All samples collected in 2020 were under the splits D and E. Although insignificant, the sample from S1 shallow (6 m) separated from the other samples. Overall, the results showed significant differences between samples collected in 2005 and 2020. Although, there were 5 lost and 8 gained taxa in 2020 none of those significantly differentiated the samples in the cluster (apart from the outlying sample from S2 at 15 m in 2005). The ‘year’ factor had a significant influence on assemblage composition within samples. 4. Discussion Despite dominating polar species numbers and being key vulnerable marine environment indicators, benthos are difficult to robustly, repeatedly sample at remote, high latitude sites. Revisiting the same Spitsbergen study area after 15 years with the exact methodology enabled us to detect changes in the structure of encrusting assemblages, mostly realised in a species dominance shift. Five taxa found in 2005 did not occur in 2020, but eight new ones were identified in samples from 2020. There are few comparable exact revisits using similar apparatus, protocols, site and target taxa (but e.g. for Antarctica see Dayton ( 1989 ) or Souster ( 2018 )). Some detection of biota differences across samples in space or time is expected, so of key importance is the extent of differences and what their drivers are. Environmental differences revealed by satellite data and supported by other studies in the Isfjorden region (e.g. Pavlov et al. 2013 ; Skogseth et al. 2020 ; Bloshkina et al. 2021 ), we argue that the shift in the structure of the epibenthic assemblage reported in this study could be the result of changes in the temperature conditions within the fjord and other parameters induced by climate change. 4.1 Environmental conditions Monthly surface temperatures in the Isfjorden area (including temperatures of water and ice, if it was present) have significantly increased throughout the whole year, but especially within the winter months (Fig. 2 ). The most drastic change in surface temperature over Isfjorden was recorded in March with mean values in 2005 of -18.3°C compared to -4.4°C in 2020. However, the temperature near the shallow sea bed was more constant. We can observe a relatively warm summer in 2019 with maximal temperatures at the bottom reaching almost 10.0°C at a depth of 7 meters, but also a relatively cold winter with averages in March of 2020 around − 1.9°C (Moreno et al. 2024 ). There has been a pronounced warming detected within the fjord with a growing presence of Atlantic water also in the bottom layers with temperatures above 3°C starting from 2013 onwards (Bloshkina et al. 2021 ). In the summer of 2014 temperatures in Isfjorden were especially high (Skogseth et al. 2020 ) and Atlantic water has been recorded even in Billefjorden (Bloshkina et al. 2021 ). There were detectable temperature differences between years and signs of marine heat spikes occurring in the Arctic with increasing frequency (Beszczynska-Mӧller et al. 2012; Promińska et al. 2017; Skogseth et al. 2020 ; Mohamed et al. 2022 ; Huang et al. 2021 ). Aside from the growing temperatures, the Arctic is also dealing with an increasing melting of sea ice, with a loss of ~ 10% per decade especially during winter occurring since 1979 (Onarheim et al. 2014 ; Muckenhuber et al. 2016) and glaciers, with mass loss of 401 ± 24 kg m − 2 a − 1 over Svalbard between 2010 and 2017 (Tepes et al. 2021 ). A significant decline in the presence of sea ice cover in Isfjorden has been observed since the beginning of this century, with substantial strengthening of this trend since 2006 (Muckenhuber et al. 2016). As a result of this process, more sea surface is accessible for phytoplankton blooms therefore, the net primary production in the Arctic region is reportedly continuously increasing (Arrigo and van Dijken, 2015 ; Frey et al. 2021 ). Under such environmental forcing, we expected the local ecosystem to have undergone noticeable changes. 4.2 Assemblage structure shift Our study documents a clear difference in the structure of the hard-bottom encrusting community between 2005 and 2020. Repeat visits to a polar fjord in Antarctica detected both an assemblage shift and identified sedimentation as a driver of this (Sahade et al. 2015). In the Arctic, several distinct changes have already been reported within other biotic components of marine ecosystems. An overall shift in hard-bottom benthic composition was already reported by Kortsch et al. ( 2012 ) around the end of the last century in Kongsfjorden. Their 30-year-long study found an abrupt increase in macroalgae (a shift from the dominance of red calcareous algae Lithothamnion sp. to filamentous brown algae Sacchoriza dermatodea ) and a concurrent increase in diversity and major change of invertebrate assemblage (shift from the dominance of sea anemones to sea urchins). Weslawski et al. ( 2010 ) reported an increase in intertidal macrobenthos diversity in the southern Svalbard (Sorkappland and Hornsund) from 19 to 43 taxa between 1988 and 2008 (using 20 cm x 20 cm frames at low tide). Newly recorded species in that study were mostly of boreal and arctic-boreal origin. In our study, after 15 years, we similarly found significant differences in the 2020 assemblage from the initial one, yet not entirely unrecognisable. All taxa recovered in both years and identified to species level have been reported in the Svalbard area (Table 4 ). However, in the early stages of the sample analysis, we observed obvious shifts in the abundances of a few dominant taxa. This included a major drop in the abundance of Harmeria scutulata and Semibalanus balanoides between 2005 and 2020 and a simultaneous increase in the number of individuals of Circeis sp., Spirorbinae indet. and cheilostome and cyclostome ancestrulae. From both groups – bryozoans and serpulids – many species are recognised as opportunistic and reported to be amongst the pioneer colonisers of a newly available hard substrate (Barnes, 1996 ; Kuklinski et al. 2013 ; Wisshak et al. 2021). Harmeria scutulata was an important species within the shallow coastal Arctic assemblages at the beginning of the century often accounting for more than 50% of bryozoan colonies in assemblages (Barnes & Kuklinski 2005 , Kuklinski and Taylor, 2006). In the current study, the maximum contribution of H . scutulata to the bryozoan assemblage on the experimental plates reached at most 33% in 2005 at the S2 shallow station and was below 1% at the same station in 2020. However, in 2014/2015 it was still one of the most frequently recorded pioneers collected in Gronfjorden (the outmost inlet of Isfjorden) (Evseeva and Dvoretsky, 2023 ), and in the eastern area of the Kola Peninsula (Evseeva et al. 2022 ). On the south bank of Isfjorden H . scutulata was also very abundant until 2014, but has become more scarce since (Sowa, unpubl. data). Like most pioneers this species is a poor spatial competitor for substrate, losing around 70% of species interactions (Barnes and Kuklinski, 2003 ). Its distribution has been reported to be circumpolar and reaches at most down to Kodiak Island in Alaska (Kuklinski and Taylor, 2006). The acorn barnacle S. balanoides has a wide boreo-arctic distribution in the North Atlantic, with an established population in the Svalbard region. It has been reported as a sentinel of climate change as its biogeographic range and reproductive success is tightly linked to temperature (Herrera et al. 2019 ; Walczynska et al. 2019). Studies held in the European intertidal have already shown contraction in the southern extent of this species by 300 km and drops in abundance in areas with warm winters (> 10°C) due to inhibited reproduction (Barnes, 1963 ; Wethey and Woodin, 2008 ; Rhiannon and Hilbish, 2014). Jones et al. ( 2012 ) reported a contraction of the southern distribution extent by 350 km on the eastern coast of the United States but concluded it to be driven by summer heat death rather than winter cold limitation of reproduction as suggested by Wethey and Woodin ( 2008 ) on the other side of the Atlantic. Short-term warm conditions can also influence the abundance of barnacles, and their temperature dependence leads to significant annual fluctuations in recruitment (Walczynska et al. 2019; Rhiannon and Hilbish, 2014). As it is a long-lived species, it is also possible that reproduction might not occur every year (Walczynska et al. 2019). A few of the noted taxa displayed an increase in abundance between the 2005 and 2020 samples. Three bryozoan species were reported to have reached higher abundances – Cylindroporella tubulosa , Microporella arctica and Tegella arctica , all typical for the Svalbard area and noted in the region previous to this study on both natural and artificial substrates (Table 4 ). This could be explained by the simultaneous decrease in the presence of H . scutulata leaving more space for other taxa. On the other hand, those species may be more resilient to changes in the environment in comparison to (the previously abundant) H . scutulata . Notably, there was a large number of juveniles (organisms younger than three months) – of both bryozoans and serpulids (Sowa, pers obs based on Sowa et al. 2023 ). That could be an indication of greater reproductive success in the spring and summer of 2020 or either a change in the timing of larvae release or the length of the pelagic stage. Coincidentally, in 2020 high cumulative intensity and duration of marine heatwaves were observed over the Barents Sea (Mohamed et al. 2022 ) which could consequently influence levels of primary production. However, serpulids have non-feeding types of larvae (lecithotrophic), which allows them to be released independently from primary production peaks (Kuklinski et al. 2013 ; Ushakova, 2003 ). Polychaete larvae were identified in the water column there throughout spring and summer (Kuklinski et al. 2013 ). However, recruitment on experimental plates has been reported to occur throughout the whole year (Kuklinski et al, 2013 ; Meyer et al. 2017 ; Sowa et al. 2023 ). Silberberger et al. ( 2016 ) reported the presence of bryozoan larvae throughout spring and summer in the sub-Arctic area (northern Norway). In the study of Kuklinski et al. ( 2013 ) in Adventfjorden (an Isfjorden inlet fiord) peaks occurred between April and June with delayed recruitment on the experimental plates. Bryozoans possess lecitotrophic or planktotrophic larvae depending on the species (Stübner et al. 2016 ). The duration of presence in the water column is about two months for feeding larvae, but less (even just a few hours) for the non-feeding type which usually remains close to the sea bottom and settles much faster and thus is rarely identified in plankton samples (Kluge, 1975 ; McKinney and Jackson, 1989; Temkin and Zimmer, 2002 ; Kuklinski et al. 2013 ). Larval release is driven by a variety of factors, for some lecithotrophic larvae the main cue is light (i.e. being released at dawn), although this might be very different in the Arctic region with the presence of polar day. They also initially display photopositive behaviour which may aid with better dispersal in that short window of time (Temkin and Zimmer, 2002 ). In the summer of 2019, the highest maximal bottom water temperatures (at depths of 7 m and 14 ± 1 m) were noted (from a period between August 2006 and July 2022) as well as a wide range of logged temperatures in winter (between 2°C in December 2019 and down to -1.7°C until April 2020, see Moreno et al. ( 2024 ). In 2020 there were intense marine heatwaves noted in the Barents Sea region (Mohamed et al. 2022 ). This seems likely to influence early onset release of larvae in the summer of 2020 that had enough time to recruit by the time of retrieval of the experimental plates. There is prior evidence that increasing temperatures in the Arctic region could lead to a shortening of larval development and quicker settlement (O’Connor et al. 2007). 4.3 New arrivals? The handful of new taxa that were identified on the plates from 2020 comprised of four Arctic species – Doryporella spathulifera , Diplosolen arctica , Tricellaria arctica , Tricellaria gracilis (Kluge, 1975 ), one Arctic-boreal – Stomachetosella cruenta (Kluge, 1975 ), one with a wider distribution, recorded even in Spain – Spirorbis tridentatus (Rzhavsky et al. 2014 ), but previously recorded with particularly high abundance in Isfjorden in 2002 (Barnes and Kuklinski, 2005 ) and 2010 (Balazy and Kuklinski, 2017 ), and one family and one genus previously recorded in the Svalbard area - Scrupocellidae and Tegella sp. differentiated by us as dark type (Kuklinski et al. 2013 ; Meyer et al. 2017 ). Of the above-mentioned species all were identified in Svalbard fjords either before 2005 or between 2005 and 2020 in previous reports (Table 4 ). Based on these data we can conclude that although the composition of the assemblage was significantly different in 2020, the species composition was still representative of that hitherto described for the Svalbard region. Some of the species, D . spathulifera , S . cruenta and T . gracilis , were reported in the samples collected by Evseeva and Dvoretsky ( 2024 ) around Franz Josef Land between 2006 and 2008 but were low in biomass. Their absence in our samples from 2005 could be a result of natural fluctuations (for example see 5 years long, a monthly record of species fluctuations at the same site by Watson and Barnes 2004 ). 4.4 Structure under factors In this study, in testing the effects of different factors, beyond investigating the influence of time (‘year’) we also included factors related to depth and geographical location (‘site’ and ‘depth’; Table 3 ). Considering the overall assemblage structure all of the factors and their interactions were statistically significant – the ‘year’ factor explaining most of the differentiation between samples (28.5%). However, for species richness and abundance, not all factors were significant, and the ‘depth’ factor was the most important for both, whereas the ‘site’ was not statistically significant. The insignificance of the ‘site’ factor could be explained by the short distances between study sites, which were approximately only two nautical miles apart. Although the depth difference was not large (~ 7 m between strata) the key difference between them was the presence of dense kelp forests around the shallower study sites. The presence of kelp could have acted as a stabiliser for the overall conditions by limiting the water movement but also provided an additional source of food (Balazy and Kuklinski, 2017 ) and habitat complexity. The kelps themselves are predicted to experience range shifts under different climate scenarios. Assis et al. (2017) predicted the potential loss of Laminaria solidungula , an endemic, stenothermic species (Lebrun et al. 2022 ) in the southwest area of Svalbard with simultaneous expansion of Laminaria hyperborean , L . digitata and Saccorhiza dermatodea around parts of the archipelago (two other species of kelp – Alaria esculenta and Saccharina latissima remaining stable). For L . digitata an increase of biomass up to four times has already been recorded (Lebrun et al. 2022 ). Although the predictions are rather optimistic for the kelps in the Arctic in the sense of biomass and distribution range increase, the composition of species will experience change that will most likely affect the associated fauna (Lebrun et al. 2022 ). The number of taxa was rather similar between the depths at the same sites (besides samples from S2 in 2005 which had very low recruitment) but the average abundance of individual recruits was higher in samples from shallower depth (7m). Obtained results showed significant differences between assemblages over the 15 years supporting the hypothesis of the study. The most influential changes observed were the shifts in dominance suggesting a reorganisation of the assemblage rather than a change in the taxonomic pool. This agrees with the nature of the shift observed for hard bottom macrofauna by Kortsch et al. ( 2012 ) in Spitsbergen fjords. On the other hand, the Arctic has been under climate change forcing long before the start of our experiment in 2004. Beszczynska-Mӧller et al. (2012) reported on a warm anomaly in the Fram Strait in 1999/2000 and Bloshkina et al. ( 2021 ) described increasing proportion and further extension of Atlantic waters in the bottom layer from 2003 onwards. Within almost a century (1912–2009) Isfjorden experienced 1.9°C of overall warming (Pavlov et al. 2013 ). Thus, the results obtained in this study may showcase the already altered state of the hard-bottom assemblage. Nonetheless, they indicate the direction of ongoing change and provide a crucial reference point for comparison in the future. Table 4 Species identified in this study compared to the species lists from other studies conducted in the Svalbard area time/area up to 2000 Svalbard 2002 Kongsfjord 2002 Hornsund 2002 Isfjorden 2007 Adventfjorden 2014/2015 Gronefjorden 2015 Svalbard 2017 Isfjorden source Palerud et al. ( 2004 ) Kuklinski and Barnes ( 2005 ) Barnes and Kuklinski ( 2005 ) Kuklinski et al. ( 2013 ) Evseeva et al. (2023) Meyer et al. ( 2017 ) Sowa et al. ( 2023 ) Arctonula arctica X X X X Callopora craticula X X X X X X X X Callopora lata X X X X Callopora lineata X X X X X Celleporella hyalina X X X X X X X X Cribrilina annulata X X X X X X X Cylindroporella tubulosa X X X X X X Doryporella spathulifera X X X X Diplosolen arctica X Electra arctica X X X X Harmeria scutulata X X X X X X X X Hippodiplosia obesa X X X Hippothoa arctica X Microporella arctica X X Myriozella crustacea X X X Raymondcia rigida X X X Smittina minuscula X X X X Stomachetosella cruenta X X X X Tegella arctica X X X X X X X Tegella armifera X X X X X Tricellaria arctica X X Tricellaria gracilis X X Tubulipora flabellaris X X X X X Semibalanus balanoides X not included not included X not included X X Spirorbis tridenatus X Circeis spirillum X X X Paradexiospira vitrea X X Chitinopoma serrula X Declarations Conflict of interests Authors declare no conflict of interests. Funding The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Data/Code availability The datasets generated during and/or analysed during the current study are not publicly available but are available from the corresponding author on reasonable request. Author’s contribution All authors contributed to the study conception and design. Field campaigns were performed by Balazy Piotr, Chelchowski Maciej. Formal analysis and investigation were performed by Sowa Anna. The first draft of the manuscript was written by Sowa Anna and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Work on the manuscript was supervised by Iglikowska Anna and Kotwicki Lech Acknowledgements Surface temperature and sea ice extent data were provided by DMI and the Copernicus CMEMS project. References Al-Habahbeh AK, Kortsch S, Bluhm BA, Beuchel F, Gulliksen B, Ballantine C, Domiziana C, Primicerio R (2020) Arctic coastal benthos long-term responses to perturbations under climate warming. Philosophical Trans Royal Soc A 378(2181):20190355 Arrigo KR, van Dijken GL (2015) Continued increases in Arctic Ocean primary production. Prog Oceanogr 136:60–70 Assis J, Araújo MB, Serrão EA (2018) Projected climate changes threaten ancient refugia of kelp forests in the North Atlantic. Glob Change Biol 24(1):e55–e66 Balazy P, Kuklinski P (2017) Arctic field experiment shows differences in epifaunal assemblages between natural and artificial substrates of different heterogeneity and origin. J Exp Mar Biol Ecol 486:178–187 Barnes DKA (1996) Low levels of colonisation in Antarctica: the role of bryozoans in early community development. Bryozoans in space and time. National Institute of Water and Atmospheric Research, pp 19–28 Barnes DKA (2015) Marine colonization and biodiversity at Ascension Island and remote islands. J Mar Biol Assoc U K 97:771–782 Barnes DKA, Kuklinski P (2003) High polar spatial competition: extreme hierarchies at extreme latitude. Mar Ecol Prog Ser 259:17–28 Barnes DKA, Kukliński P (2005) Low colonisation on artificial substrata in arctic Spitsbergen. Polar Biol 29:65–69 Barnes H (1963) Light, temperature and the breeding of Balanus balanoides . J Mar Biol Association United Kingd 43(3):717–727 Beisiegel K, Darr A, Gogina M, Zettler ML (2017) Benefits and shortcomings of non-destructive benthic imagery for monitoring hard-bottom habitats. Mar Pollut Bull 121(1–2):5–15 Beszczynska-Möller A, Fahrbach E, Schauer U, Hansen E (2012) Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997–2010. ICES J Mar Sci 69(5):852–863 Beuchel F, Gulliksen B (2008) Temporal patterns of benthic community development in an Arctic fjord (Kongsfjorden, Svalbard): results of a 24-year manipulation study. Polar Biol 31(8):913–924 Beuchel F, Gulliksen B, Carroll ML (2006) Long-term patterns of rocky bottom macrobenthic community structure in an Arctic fjord (Kongsfjorden, Svalbard) in relation to climate variability (1980–2003). J Mar Syst 63(1–2):35–48 Bloshkina EV, Pavlov AK, Filchuk K (2021) Warming of Atlantic Water in three west Spitsbergen fjords: recent patterns and century-long trends. Polar Res, 40 Bowden DA, Clarke A, Peck LS, Barnes DKA (2006) Antarctic sessile marine benthos: colonisation and growth on artificial substrata over three years. Mar Ecol Prog Ser 316:1–16 Chan FT, Stanislawczyk K, Sneekes AC, Dvoretsky A, Gollasch S, Minchin D, Bailey SA (2019) Climate change opens new frontiers for marine species in the Arctic: Current trends and future invasion risks. Glob Change Biol 25(1):25–38 Clarke KR, Somerfield PJ, Gorley RN (2008) Testing of null hypotheses in exploratory community analyses: similarity profiles and biota-environment linkage. J Exp Mar Biol Ecol 366:56–69 Conlan KE, Kvitek RG (2005) Recolonization of soft-sediment ice scours on an exposed Arctic coast. Mar Ecol Prog Ser 286:21–42 Cottier FR, Nilsen F, Inall ME, Gerland S, Tverberg V, Svendsen H (2007) Wintertime warming of an Arctic shelf in response to large-scale atmospheric circulation. Geophys Res Lett, 34(10) Dalpadado P, Ingvaldsen RB, Stige LC, Bogstad B, Knutsen T, Ottersen G, Ellertsen B (2012) Climate effects on Barents Sea ecosystem dynamics. ICES J Mar Sci 69(7):1303–1316 Dayton PK (1989) Interdecadal variation in an Antarctic sponge and its predators from oceanographic climate shifts. Science 245:1484–1496 Evseeva OY, Dvoretsky AG (2023) Shallow-water bryozoan communities in a glacier fjord of West Svalbard, Norway: Species composition and effects of environmental factors. Biology 12(2):185 Evseeva OY, Dvoretsky AG (2024) Bryozoan communities off Franz Josef Land (northern Barents Sea, Russia): Distribution patterns and environmental control. J Mar Syst 242:103944 Evseeva OY, Ishkulova TG, Dvoretsky AG (2022) Environmental drivers of an intertidal bryozoan community in the Barents Sea: A case study. Animals 12(5):552 Fossheim M, Primicerio R, Johannesen E, Ingvaldsen RB, Aschan MM, Dolgov AV (2015) Recent warming leads to a rapid borealization of fish communities in the Arctic. Nat Clim change 5(7):673–677 Fraser NJ, Skogseth R, Nilsen F, Inall ME (2018) Circulation and exchange in a broad Arctic fjord using glider-based observations. Polar Res 37(1):1485417 Frey KE, Comiso JC, Cooper LW, Grebmeier JM, Stock LV (2021) Arctic ocean primary productivity: The response of marine algae to climate warming and sea ice decline. Arctic Report Card Friedlander AM, Ballesteros E, Adler AM, Goodell W, Jenkinson R, Knopp JA, Sala E (2023) Shallow subtidal marine benthic communities of Nachvak Fjord, Nunatsiavut, Labrador: A glimpse into species composition and drivers of their distribution. PLoS ONE, 18(11), e0293702 Górska B, Gromisz S, Legeżyńska J, Soltwedel T, Włodarska-Kowalczuk M (2022) Macrobenthic diversity response to the atlantification of the Arctic Ocean (Fram Strait, 79° N)–A taxonomic and functional trait approach. Ecol Ind 144:109464 Gray JS, Christie H (1983) Predicting long-term changes in marine benthic communities. Mar Ecol progress Ser Oldendorf 13(1):87–94 Herrera M, Wethey DS, Vázquez E, Macho G (2019) Climate change implications for reproductive success: temperature effect on penis development in the barnacle Semibalanus balanoides. Mar Ecol Prog Ser 610:109–123 Huang B, Wang Z, Yin X, Arguez A, Graham G, Liu C, Zhang HM (2021) Prolonged marine heatwaves in the Arctic: 1982 – 2020. Geophys Res Lett, 48(24), e2021GL095590. Jones SJ, Southward AJ, Wethey DS (2012) Climate change and historical biogeography of the barnacle Semibalanus balanoides. Glob Ecol Biogeogr 21(7):716–724 Jordà-Molina È, Renaud PE, Silberberger MJ, Sen A, Bluhm BA, Carroll ML, Reiss H (2023) Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord. Mar Environ Res, 106046 Kennedy EV, Ordoñez A, Lewis BE, Diaz-Pulido G (2017) Comparison of recruitment tile materials for monitoring coralline algae responses to a changing climate. Mar Ecol Prog Ser 569:129–144 Klekowski RZ, Weslawski JM (1991) Atlas of the marine fauna of southern Spitsbergen, Vol. 2(part 3), Institute of Oceanography, Poland, 152 pp Kluge GA (1975) Bryozoa of the northern seas of the USSR. Keys on the fauna of the USSR published by the Zoological Institute. Acad Sci USSR 76:1–711 Kortsch S, Primicerio R, Beuchel F, Renaud PE, Rodrigues J, Lønne OJ, Gulliksen B (2012) Climate-driven regime shifts in Arctic marine benthos. Proceedings of the National Academy of Sciences , 109 (35), 14052–14057 Kotwicki L, Weslawski JM, Włodarska-Kowalczuk M, Mazurkiewicz M, Wenne R, Zbawicka M, Olenin S (2021) The re-appearance of the Mytilus spp. complex in Svalbard, Arctic, during the Holocene: The case for an arrival by anthropogenic flotsam. Glob Planet Change 202:103502 Kuklinski P, Balazy P, Porter J, Loxton J, Ronowicz M, Sokołowski A (2022) Experimental apparatus for investigating colonization, succession and related processes of rocky bottom epifauna. Cont Shelf Res 233:104641 Kuklinski P, Barnes DKA (2005) Bryodiversity on coastal boulders at Spitsbergen. Bryozoan studies 2004. CRC, pp 171–182 Kuklinski P, Berge J, McFadden L, Dmoch K, Zajaczkowski M, Nygård H, Piwosz K, Tatarek A (2013) Seasonality of occurrence and recruitment of Arctic marine benthic invertebrate larvae in relation to environmental variables. Polar Biol 36(4):549–560 Lantuit H, Overduin PP, Couture N, Wetterich S, Aré F, Atkinson D, Vasiliev A (2012) The Arctic coastal dynamics database: A new classification scheme and statistics on Arctic permafrost coastlines. Estuaries Coasts 35:383–400 Lebrun A, Comeau S, Gazeau F, Gattuso JP (2022) Impact of climate change on Arctic macroalgal communities. Glob Planet Change 219:103980 McKinney FK, Jackson JB (1991) Bryozoan evolution. University of Chicago Press Meyer KS, Sweetman AK, Kuklinski P, Leopold P, Vogedes D, Berge J, Griffiths C, Young CM, Renaud PE (2017) Recruitment of benthic invertebrates in high Arctic fjords: Relation to temperature. depth. and season. Limnol Oceanogr 62(6):2732–2744 Mohamed B, Nilsen F, Skogseth R (2022) Marine heatwaves characteristics in the barents sea based on high resolution satellite data (1982–2020). Front Mar Sci 9:821646 Moreno B, Sowa A, Reginia K, Balazy P, Chelchowski M, Ronowicz M, Kuklinski P (2024) Sea water temperature and light intensity at high-Arctic subtidal shallows–16 years perspective. Sci Data 11(1):227 Nicoletti L, Marzialetti S, Paganelli D, Ardizzone GD (2007) Long-term changes in a benthic assemblage associated with artificial reefs. Hydrobiologia 580(1):233–240 Nilsen F, Cottier F, Skogseth R, Mattsson S (2008) Fjord–shelf exchanges controlled by ice and brine production: the interannual variation of Atlantic Water in Isfjorden. Svalbard Cont Shelf Res 28(14):1838–1853 O'Connor MI, Bruno JF, Gaines SD, Halpern BS, Lester SE, Kinlan BP, Weiss JM (2007) Temperature control of larval dispersal and the implications for marine ecology, evolution, and conservation. Proceedings of the National Academy of Sciences, 104(4), 1266–1271 Onarheim IH, Smedsrud LH, Ingvaldsen RB, Nilsen F (2014) Loss of sea ice during winter north of Svalbard. Tellus A: Dynamic Meteorol Oceanogr 66(1):23933 Overland J, Dunlea E, Box JE, Corell R, Forsius M, Kattsov V, Wang M (2019) The urgency of Arctic change. Polar Sci 21:6–13 Palerud R, Gulliksen B, Brattegard T, Sneli JA, Vader W (2004) The marine macro-organisms in Svalbard waters. A catalogue of the terrestrial and marine animals of Svalbard. Norsk Polarinstitutt Skrifter 201:5–56 Paulsen ML, Dore H, Garczarek L, Seuthe L, Mueller O, Sandaa RA, Larsen A (2016) Synechococcus in the Atlantic gateway to the Arctic Ocean. Front Mar Sci 3:191 Pavlov AK, Tverberg V, Ivanov BV, Nilsen F, Falk-Petersen S, Granskog MA (2013) Warming of Atlantic Water in two west Spitsbergen fjords over the last century (1912–2009). Polar Res 32(1):11206 Piepenburg D (2005) Recent research on Arctic benthos: common notions need to be revised. Polar Biol 28(10):733–755 Promińska A, Falck E, Walczowski W (2018) Interannual variability in hydrography and water mass distribution in Hornsund, an Arctic fjord in Svalbard. Polar Res 37(1):1495546 Rantanen M, Karpechko AY, Lipponen A, Nordling K, Hyvärinen O, Ruosteenoja K, Vihma T, Laaksonen A (2022) The Arctic has warmed nearly four times faster than the globe since 1979. Commun Earth Environ 3(1):1–10 Renaud PE, Berge J, Varpe Ø, Lønne OJ, Nahrgang J, Ottesen C, Hallanger I (2012) Is the poleward expansion by Atlantic cod and haddock threatening native polar cod, Boreogadus saida? Polar Biol 35:401–412 Renaud PE, Riedel A, Michel C, Morata N, Gosselin M, Juul-Pedersen T, Chiuchiolo A (2007) Seasonal variation in benthic community oxygen demand: a response to an ice algal bloom in the Beaufort Sea, Canadian Arctic? J Mar Syst 67(1–2):1–12 Renaud PE, Sejr MK, Bluhm BA, Sirenko B, Ellingsen IH (2015) The future of Arctic benthos: expansion, invasion, and biodiversity. Prog Oceanogr 139:244–257 Rognstad RL, Hilbish TJ (2014) Temperature-induced variation in the survival of brooded embryos drives patterns of recruitment and abundance in Semibalanus balanoides. J Exp Mar Biol Ecol 461:357–363 Rzhavsky AV, Kupriyanova EK, Sikorski AV, Dahle S (2014) Calcareous tubeworms (Polychaeta, Serpulidae) of the Arctic Ocean. KMK Scientific, Moscow, Russia, pp 1–187 Silberberger MJ, Renaud PE, Espinasse B, Reiss H (2016) Spatial and temporal structure of the meroplankton community in a sub-Arctic shelf system. Mar Ecol Prog Ser 555:79–93 Skogseth R, Olivier LL, Nilsen F, Falck E, Fraser N, Tverberg V, Falk-Petersen S (2020) Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation–An indicator for climate change in the European Arctic. Prog Oceanogr 187:102394 Souster T, Barnes DKA, Primicerio R, Jørgensen LL (2024) Quantifying zoobenthic blue carbon storage across habitats within the Arctic’s Barents Sea. Front Mar Sci. org/10.3389/fmars.2023.1260884 Souster TA (2018) Marine Biodiversity of Antarctic Hard Rock Communities: Species Biomass and Energy Use. PhD thesis The Open University Sowa A, Kuklinski P, Weydmann-Zwolicka A, Balazy P, Chelchowski M, Søreide JE, Ronowicz M (2023) Factors shaping epibionts recruitment in the high Arctic (Isfjorden, Spitsbergen): A year-round investigation using experimental plates. Estuarine, Coastal and Shelf Science, 283, 108281 StatSoft Inc (2007) STATISTICA (data analysis software system), version 8.0. Stübner EI, Søreide JE, Reigstad M, Marquardt M, Blachowiak-Samolyk K (2016) Year-round meroplankton dynamics in high-Arctic Svalbard. J Plankton Res 38(3):522–536 Temkin MH, Zimmer RL (2002) Phylum bryozoa. Atlas of marine invertebrate larvae, 411–427 Tepes P, Gourmelen N, Nienow P, Tsamados M, Shepherd A, Weissgerber F (2021) Changes in elevation and mass of Arctic glaciers and ice caps, 2010–2017. Remote Sens Environ 261:112481 Ushakova OO (2003) Combined effect of salinity and temperature on Spirorbis spirorbis L. and Circeus spirillum L. larvae from the White Sea. J Exp Mar Biol Ecol 296(1):23–33 Voronkov A, Hop H, Gulliksen B (2016) Zoobenthic communities on hard-bottom habitats in Kongsfjorden. Svalbard Polar Biology 39:2077–2095 Walczyńska KS, Søreide JE, Weydmann-Zwolicka A, Ronowicz M, Gabrielsen TM (2019) DNA barcoding of Cirripedia larvae reveals new knowledge on their biology in Arctic coastal ecosystems. Hydrobiologia 837:149–159 Wassmann P, Duarte CM, Agusti S, Sejr MK (2011) Footprints of climate change in the Arctic marine ecosystem. Glob Change Biol 17(2):1235–1249 Watson DI, Barnes DKA (2004) Temporal and spatial components of variability in benthic recruitment, a 5-year temperate example. Mar Biol 145(1):201–214 Weslawski JM, Wiktor J, Kotwicki L (2010) Increase in biodiversity in the arctic rocky littoral, Sorkappland, Svalbard, after 20 years of climate warming. Marine Biodivers 40:123–130 Wethey DS, Woodin SA (2008) Ecological hindcasting of biogeographic responses to climate change in the European intertidal zone. In Challenges to Marine Ecosystems: Proceedings of the 41st European Marine Biology Symposium (pp. 139–151). Springer Netherlands Wisshak M, Meyer N, Kuklinski P, Rüggeberg A, Freiwald A (2022) Ten Years After’—a long-term settlement and bioerosion experiment in an Arctic rhodolith bed (Mosselbukta, Svalbard). Geobiology 20(1):112–136 Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4389944","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":315549243,"identity":"2f69ec89-dc08-46ea-ba4d-e55adafcedb6","order_by":0,"name":"Anna Sowa","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5klEQVRIiWNgGAWjYNCDD0DMxk6KDsYZIC3MpGhh5gGTBFTxsx8++Llwhx2DfHuP4WebX9vk+ZgZGD98zMGtRbInLVl65plkBoMzZ4ylc/tuG7YxMzBLztyGW4vBDR4DaV6gMgOJ3A3SuT23GYFsNmZevFr4P//mbatnkJ+Ru/m3Zc9teyK08LABbTnMwHAjd5s0w4/biQS1AP1iZs3bdpzH4Mz5b5a9DbeT25gZm/H6BRhij2/ztlXLybe3Jd/48ee27fz25oMfPuLRAgPgGGFgbAOTDYTVI8AfUhSPglEwCkbBSAEAd9NJkXPMKlkAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0001-7123-6529","institution":"Polish Academy of Sciences Institute of Oceanology: Instytut Oceanologii Polskiej Akademii Nauk","correspondingAuthor":true,"prefix":"","firstName":"Anna","middleName":"","lastName":"Sowa","suffix":""},{"id":315549244,"identity":"00ef09a2-70fe-4b93-8af7-662cb5a92db6","order_by":1,"name":"Piotr Balazy","email":"","orcid":"","institution":"Polish Academy of Sciences Institute of Oceanology: Instytut Oceanologii Polskiej Akademii Nauk","correspondingAuthor":false,"prefix":"","firstName":"Piotr","middleName":"","lastName":"Balazy","suffix":""},{"id":315549245,"identity":"6b00b528-60fa-425e-99f5-6875ba5e3ba7","order_by":2,"name":"Maciej Chelchowski","email":"","orcid":"","institution":"Polish Academy of Sciences Institute of Oceanology: Instytut Oceanologii Polskiej Akademii Nauk","correspondingAuthor":false,"prefix":"","firstName":"Maciej","middleName":"","lastName":"Chelchowski","suffix":""},{"id":315549246,"identity":"29a86e55-deba-42e3-a2b2-ac0137b67d43","order_by":3,"name":"Maria Włodarska-Kowalczuk","email":"","orcid":"","institution":"Polish Academy of Sciences Institute of Oceanology: Instytut Oceanologii Polskiej Akademii Nauk","correspondingAuthor":false,"prefix":"","firstName":"Maria","middleName":"","lastName":"Włodarska-Kowalczuk","suffix":""},{"id":315549247,"identity":"e63abf54-b25e-4fd2-b9c3-f159e87c1d64","order_by":4,"name":"David Barnes","email":"","orcid":"","institution":"BAS: British Antarctic Survey","correspondingAuthor":false,"prefix":"","firstName":"David","middleName":"","lastName":"Barnes","suffix":""},{"id":315549248,"identity":"de59ebd1-eba2-4768-bcb7-deaf75d2c243","order_by":5,"name":"Anna Iglikowska","email":"","orcid":"","institution":"University of Gdansk: Uniwersytet Gdanski","correspondingAuthor":false,"prefix":"","firstName":"Anna","middleName":"","lastName":"Iglikowska","suffix":""},{"id":315549249,"identity":"44e84243-5193-44da-9cb2-6c42b2857156","order_by":6,"name":"Lech Kotwicki","email":"","orcid":"","institution":"Polish Academy of Sciences Institute of Oceanology: Instytut Oceanologii Polskiej Akademii Nauk","correspondingAuthor":false,"prefix":"","firstName":"Lech","middleName":"","lastName":"Kotwicki","suffix":""}],"badges":[],"createdAt":"2024-05-08 14:25:00","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4389944/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4389944/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":60019479,"identity":"142d85ec-8847-43fd-9c8d-d4e80ad20e02","added_by":"auto","created_at":"2024-07-10 15:25:58","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":955868,"visible":true,"origin":"","legend":"\u003cp\u003eMap of the locations of the study sites S1 (78.21292°N, 15.23556° E) and S2 (78.1883° N, 15.1447° E) on the southern bank of Isfjorden (Svalbard, North East Atlantic Ocean).\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/c37f7f8a8da5ec52f6ae72a4.png"},{"id":60018941,"identity":"442526a3-8a7c-4dd6-a219-7fd1de1bddb8","added_by":"auto","created_at":"2024-07-10 15:17:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":665546,"visible":true,"origin":"","legend":"\u003cp\u003eMonthly mean Surface Temperature (includes data recorded by satellite over water and ice surface) and Sea Ice Concentration (fractional coverage of the grid cell, in this case, 5 km × 5 km that was covered by the sea ice) for the two periods of sample submersion (from July to July) with whiskers indicating standard deviation\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/faa79b558e6581f185744dd1.png"},{"id":60018944,"identity":"29a2987f-4697-44c0-bfa5-886b8cf249a9","added_by":"auto","created_at":"2024-07-10 15:17:58","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":2130552,"visible":true,"origin":"","legend":"\u003cp\u003eShadeplot displaying the abundances of identified taxa per plate (100 cm\u003csup\u003e2\u003c/sup\u003e) from 2005 and 2020 sampling at two study sites and two depths. Raw data were square root transformed\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/618a0e1f94ead351c4f444b2.png"},{"id":60020080,"identity":"1d88a404-ca6a-47ee-abdd-f42927593ff8","added_by":"auto","created_at":"2024-07-10 15:33:58","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1083459,"visible":true,"origin":"","legend":"\u003cp\u003eMean number of ind. per 100 cm\u003csup\u003e2\u003c/sup\u003e with standard deviation bars on plates collated in two years, stations, and depths for the seven most abundant taxa (with mean number of ind. per 100 cm\u003csup\u003e2\u003c/sup\u003e ≥ 100 in any replicate)\u003c/p\u003e","description":"","filename":"Fig.4.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/42c9e249d1af34d5f3ed64a1.png"},{"id":60018945,"identity":"effadebc-29cc-422f-b93b-3835963cc902","added_by":"auto","created_at":"2024-07-10 15:17:59","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":508948,"visible":true,"origin":"","legend":"\u003cp\u003eMean values (calculated from 3 replicates) of species richness and abundance of individuals in 2005 and 2020 at two stations and depths. Whiskers represent minimal and maximal values. \u0026nbsp;Study site S1 is displayed in blue squares (on the left) and S2 in red triangles (on the right). Unfilled symbols were assigned to shallower study sites (7 m), and filled symbols to the deeper sites (13 m and 15 m)\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/f24c643963e8f3f86bea23e2.png"},{"id":60018946,"identity":"e700319c-da12-4618-902f-ca9c3bd0a4cf","added_by":"auto","created_at":"2024-07-10 15:17:59","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":769483,"visible":true,"origin":"","legend":"\u003cp\u003eLinkage tree analysis (LINKTREE) showing the partitioning of samples obtained by the five splits (A–E). Black, solid lines represent statistically significant splits, according to the SIMPROF tests performed on averaged data from the replicates; grey, dotted lines imply splits without statistical significance in this analysis.\u003c/p\u003e","description":"","filename":"Fig.6.png","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/2d9fc0ef1716d727581fe929.png"},{"id":61664987,"identity":"bb2ca7a7-f527-453e-b785-434c6b8365a0","added_by":"auto","created_at":"2024-08-02 15:46:35","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6536260,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4389944/v1/de391761-e2fb-4d80-954b-a4553eafba0c.pdf"}],"financialInterests":"","formattedTitle":"They always say time changes things – a comparative study of epibenthic assemblage in high Arctic fjord between 2005 and 2020","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eMost of the Arctic has experienced sustained intense warming for decades with the pace of this change being up to fourfold faster compared with the global average (Rantanen et al. \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Shallow coastal areas, besides having highly unstable conditions (Balazy and Kuklinski, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Beuchel et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), are especially exposed to climate change influences (Friedlander et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The continued increase in temperature leads to growing calving and consequently, ice scour (Conlan and Kvitek, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). On the other hand, sea ice in the coastal areas acts as a buffer to erosion caused by storms. With its continuous decrease and growing intensity and frequency of storm activity the shores will be exposed to greater deterioration (Lantuit et al. 2011). With these changes superimposed over freshening, sea level rise and acidification, it is important to monitor the responses across ecosystems, rather than focus (as many studies do) on a few large, charismatic species. When it comes to the Arctic assemblages a main stumbling block for evaluation of the impacts of climate change is the lack of reliable baseline information (Wassmann et al. \u003cspan citationid=\"CR77\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). The Arctic has already been under the influence of ongoing and accelerating warming for about five decades probably leading to shifts in many ecosystem elements long before they become a focus of research studies (Friedlander et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Therefore, it is crucial to fill that knowledge void to subsequently increase the interpretive power of future assessments, such as if the predictions of increasing range shift of boreal species are being realised (Renaud et al. \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; G\u0026oacute;rska et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the Arctic, benthos encompasses over 90% of described marine fauna species (Evseeva et al. 2023). Many sessile taxa colonise the coastal regions, typically characterised by hard or mixed substrates (Dunlop et al. 2020). Benthic assemblages that predominantly lead a sedentary or sessile life in the subtidal are thought to be important indicators of environmental change (Evseeva et al. 2024; Jorda-Molina et al. 2023; Beuchel et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Previous studies on benthic response to environmental forcing revealed that benthic groups can display delayed feedback due to consequent lags connected to altered diet, feeding rates and eventually the reproductive rates and/or success (Beuchel et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). This could be true when no direct influence on the sessile organism has been exerted (Gray and Christie, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e1983\u003c/span\u003e). With stronger changes in the environment, responses of immobile (as adults) fauna could be more drastic, especially for species with narrow tolerances, for example to temperature (Renaud et al. 2019). It is expected that more species of boreal origin may shift range to the Arctic waters with regional warming, to maintain their \u0026lsquo;temperature envelope\u0026rsquo; (Renaud et al. \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; G\u0026oacute;rska et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). A flag example of this process is the return of the blue mussel (\u003cem\u003eMytilus edulis\u003c/em\u003e) in the Svalbard region (Berge et al. 2005; Kotwicki et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Furthermore, several expansions of boreal species \u003cem\u003eCalanus finmarchicus\u003c/em\u003e with the simultaneous retreat of Arctic species \u003cem\u003eC\u003c/em\u003e. \u003cem\u003eglacialis\u003c/em\u003e and \u003cem\u003eC\u003c/em\u003e. \u003cem\u003ehyperboreus\u003c/em\u003e (Dalpadado et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), as well as a northward shift of the stock of Atlantic cod and haddock (Fossheim et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Renaud et al. \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) into the Barents Sea region were reported since as early as 2004. Others have reported changes in the structure of algae assemblages, with a major dominance of \u003cem\u003eSynechococcus\u003c/em\u003e in the Arctic waters where it had not been previously, commonly found (Paulsen et al. \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In the benthic realm, the expansion of \u003cem\u003eGammarus oceanicus\u003c/em\u003e has been observed to be coincident with warming of Spitsbergen shores (Weslawski et al. \u003cspan citationid=\"CR79\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Likewise G\u0026oacute;rska et al. (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) reported increased presence of cosmopolitan (\u003cem\u003eMaldane sarsi\u003c/em\u003e) and arctic-boreal (e.g. \u003cem\u003eGalathowanie oculata\u003c/em\u003e and \u003cem\u003ePrionospio cirrifera\u003c/em\u003e) polychaetes in the deep Fram Strait. In the intertidal of the eastern Kola Peninsula region, new records of a bryozoan have been reported \u0026ndash; \u003cem\u003eValkeria uva\u003c/em\u003e, a species of boreal origin previously known from the area to the west of Kola Bay (Evseeva et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). In another study focusing on Franz Josef Land, Evseeva and Dvoretsky (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) identified 22 new records of species in the study region, with 7 having boreal origins. In both cases, the establishment of the new records was attributed to the growing temperatures, although transport vectors have increased and many other stressors altered as well. As the Svalbard region is under intense influence of warm Atlantic waters carried by West Spitsbergen Current we expect to see severe changes in epibenthic assemblage dynamics there.\u003c/p\u003e \u003cp\u003ePrevious studies of the hard-bottom assemblages in the Arctic tend to focus on one-year snapshots (Kuklinski and Barnes, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Barnes and Kuklinski, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Voronkov et al. \u003cspan citationid=\"CR75\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Evseeva et al. 2023) or seasonal aspects of recruitment (Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Meyer et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Sowa et al. \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). One-year snapshots have allowed comparisons in macro space (Barnes, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) but rarely time (but see Watson and Barnes, \u003cspan citationid=\"CR78\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). A 2\u0026ndash;3 year study in deeper water found little effect of a sampling year, but these were close together (2017-19, see Souster et al. \u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Multi-year, long-term research by Beuchel et al. (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), Beuchel and Gulliksen (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) and Al-Habahbeh et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) at 79\u0026deg;N Kongsfjorden have yielded insight into succession processes on natural substrate over few decades. However, the taxonomic resolution of these studies was very different due to the samples being photographic images, which can lead to underreporting of taxonomic richness (Beisiegel et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhen attempting to evaluate the influence of long temporal-scale processes such as climate change on the biodiversity and structure of marine communities and detangling it from natural variability a meaningful baseline is crucial (Jorda-Molina et al. 2023; Chan et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Wassmann et al. \u003cspan citationid=\"CR77\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Beuchel et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Nonetheless, the base information is often lacking especially in remote areas characterised by extreme conditions. Additional problems arise when dealing with the hard-bottom communities for which the experimental protocol is difficult without the engagement of SCUBA divers (Nicoletti et al. \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Renaud et al. \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The use of experimental constructions that can be removed from the environment at the end of the project and which have limited lasting influence on the natural ecosystem fit well with increasing attempts at employing less invasive means of studying the environment (Bowden et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Kuklinski et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The uniformity of such artificial substrata and associated methodology aids comparability of replicates and results (Barnes, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1996\u003c/span\u003e; Kennedy et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Kuklinski et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Furthermore, settlement plates made from black, homogenous plastic \u0026ndash; HIPS (High Impact Polystyrene) have been used in many studies in the Arctic region and all supported settlement of zoo- and phytobenthos (e.g. Barnes and Kuklinski, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Meyer et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Sowa et al. \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Kennedy et al. (\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) showed that plastic materials can accurately approximate natural coralline algae assemblages.\u003c/p\u003e \u003cp\u003eGiven the intense climate forced changes already described in the Arctic, we hypothesise that epibenthic assemblages of the shallow coastal zone in Isfjorden would show compositional responses after 15 years. To measure any such assemblage changes our study aimed to 1) describe the structure of a subtidal, hard-bottom assemblage to provide baseline information, 2) repeat protocol at the same study location to reanalyse assemblages recovered after the same immersion period but after 15 years, 3) investigate the influence of two additional factors (\u0026lsquo;site\u0026rsquo; and \u0026lsquo;depth\u0026rsquo;) and 4) track any possible arrival of new species, especially of Atlantic origin.\u003c/p\u003e"},{"header":"2. Material \u0026 methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Study area\u003c/h2\u003e \u003cp\u003eIsfjorden (78.33\u0026deg; N, 15.00\u0026deg; E) is the largest fjord of West Spitsbergen (Nilsen et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). It lacks a sill at the mouth, which allows the free inflow of two major water masses influencing this area. West Spitsbergen Current, carries Atlantic Water (Θ\u0026thinsp;\u0026gt;\u0026thinsp;3\u0026deg;C, 35.1\u0026thinsp;\u0026lt;\u0026thinsp;S\u003csub\u003eA\u003c/sub\u003e \u0026lt; 35.4 g/kg) and the extension of the Spitsbergen Polar Current, transports Arctic Water (Θ\u0026thinsp;\u0026lt;\u0026thinsp;1\u0026deg;C, 34.5\u0026thinsp;\u0026lt;\u0026thinsp;S\u003csub\u003eA\u003c/sub\u003e \u0026lt; 35 g/kg) from the Barents Sea region (Θ \u0026ndash; conservative temperature, S\u003csub\u003eA\u003c/sub\u003e \u0026ndash; absolute salinity; Fraser et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe study period of field deployments spanned 2004\u0026ndash;2005 and 2019\u0026ndash;2020. Between these sample intervals, a distinct shift in environmental conditions was recorded in Isfjorden. Since the winter of 2006, a switch was detected from an Arctic Water state to an increased inflow of Atlantic Water, even in winter, with a subsequent decline in sea ice presence in the fjord (Cottier et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Muckenhuber et al. 2016; Skogseth et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The southern bank of Isfjorden also lacks any tidewater glaciers.\u003c/p\u003e \u003cp\u003eWithin the fjord, on the southern bank near Grumantbyen, two sites, S1 (78.21292\u0026deg;N, 15.23556\u0026deg; E) and S2 (78.1883\u0026deg; N, 15.1447\u0026deg; E) were visited and sampled at two depths (7 and 14\u0026thinsp;\u0026plusmn;\u0026thinsp;1 m). The natural substrate there was mainly hard comprising of rocks and boulders with pockets of sand at both locations. The infralittoral (depth\u0026thinsp;\u0026lt;\u0026thinsp;10 m) was vegetated by dense kelp forests, while the shallow circalittoral (depth\u0026thinsp;\u0026gt;\u0026thinsp;10 m) was mostly barren (Balazy and Kuklinski, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Protocol\u003c/h2\u003e \u003cp\u003eThe investigation into the benthic assemblage structure there was conducted using experimental constructions, which held exchangeable panels with three black settlement plates (replicates; 15 cm \u0026times; 15 cm; High Impact Polystyrene). A full description of the constructions can be found in Kuklinski et al. (\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The first settlement plates were submerged in the summer of 2004 and retrieved a year later in 2005. Another set of similar apparatus was submerged after 15 years in the summer of 2019 and collected in 2020. All fieldwork operations were conducted by the SCUBA divers from the IO PAN Scientific Diving Team.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Analysis\u003c/h2\u003e \u003cp\u003eThe panel samples with colonists were analysed under a stereoscopic microscope Leica M205C with a focus on the central area of the plates (10 cm \u0026times; 10 cm) to minimise \u0026lsquo;edge effect\u0026rsquo; as recommended by Harris (1988). A specially designed frame with 1 cm x 1 cm grid was used to eliminate the plate's unrepresentative edge during the analysis. The encrusting fauna was identified morphologically to the lowest possible taxonomic level (Klekowski and Weslawski, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e1991\u003c/span\u003e; Kluge, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1975\u003c/span\u003e; Rzhavsky et al. \u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) and counted. In case of colonial organisms, a colony was counted as a singular organism. Data preparation, statistical analysis and visualisation were performed using Microsoft Excel, Statistica software (StatSoft, Inc., 2007) and Primer v.7 (Clarke et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Three-way PERMANOVA was used to test the differences in species richness, abundance and taxonomic composition on plates among three factors (year, site, depth; all fixed and with two levels each) and their interactions. Square root transformed data were used for this analyses. ANOSIM analysis was used to test for differences between abundances of selected species among the \u0026lsquo;year\u0026rsquo; factor. For all further analysis, we used data averaged from three replicate plates. To test the structure of the assemblages we applied the LINKTREE analysis, which groups samples based on SIMPROF similarity profile tests. At each division level, a set of taxa that differentiated the samples was identified and cut-off values were given. The conditions that provided the best results were as follows: minimum group size\u0026thinsp;=\u0026thinsp;1, minimum split size\u0026thinsp;=\u0026thinsp;3, and minimum split R\u0026thinsp;=\u0026thinsp;0.5. The shadeplot was prepared to show the relative abundances of all the identified taxa as well as a bar plot to display the most abundant taxa (chosen based on the mean number of individuals being equal or higher than 100 in any sample). Diversity indices were also calculated including Shannon\u0026ndash;Wiener species diversity index (ln-based; H\u0026rsquo;) and Pielou evenness index (J\u0026rsquo;).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Temperature and sea ice\u003c/h2\u003e \u003cp\u003eTo provide environmental background we obtained satellite data from the Isfjorden region for the time of the plate submersion. These data were provided by the Danish Meteorological Institute and the Copernicus CMEMS project (Original Dataset: cmems_obs_si_arc_phy_my_L4-DMIOI_P1D-m; Translation Date: 2022-10-03). The original data were averaged for every month for two periods: from July 2004 to July 2005 and from July 2019 to July 2020. From the dataset, Surface Temperature (which includes data recorded by satellite over water and ice surface) and Sea Ice Fraction (the fraction of the ocean covered with sea ice) were obtained. The geospatial coordinates limits used were 76.5\u0026deg; \u0026minus;\u0026thinsp;79.5\u0026deg; N and 10.97\u0026deg; \u0026minus;\u0026thinsp;17.47\u0026deg; E, with a resolution of 0.05\u0026deg;. All the operations on the data were performed using Python in the Google Colaboratory environment.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cp\u003eIn total, over 20,000 individuals were identified on the 24 experimental settlement plates recovered from 7 and 14\u0026thinsp;\u0026plusmn;\u0026thinsp;1 m, at two sites. The total abundance in 2005 (7547) and 2020 (13,111) differed by \u0026gt;\u0026thinsp;5000, while the means per plate (100 cm\u003csup\u003e2\u003c/sup\u003e) were the equivalent to 1092.6\u0026thinsp;\u0026plusmn;\u0026thinsp;350.4 (2005) and 628.9\u0026thinsp;\u0026plusmn;\u0026thinsp;333.2 (2020). Overall, 47 taxa were identified to lowest possible taxonomic level (27 to species level) and represented three Phyla: Bryozoa (38 taxa), Annelida (7 taxa) and Arthropoda (2 taxa). In samples from 2005, we differentiated 39 taxa (18.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e), compared with 42 (22.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3 per 100 cm\u003csup\u003e2\u003c/sup\u003e) occurring on the plates in 2020 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEnvironmental settings differed between two study periods. 2019/2020 was warmer than 2004/2005, especially during winter months (January to April). The biggest differences (13.88\u0026deg;C between average values) in March could be attributed to the presence of sea ice in the fjord that influenced the measurements of surface temperature over the Isfjorden area. Although Isfjorden has been largely ice-free since 2006 (Muckenhuber et al. 2016), ice was recorded during the winter of 2020.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Cheilostomata bryozoans \u003cem\u003eArctonula arctica\u003c/em\u003e, \u003cem\u003eCallopora lata\u003c/em\u003e, \u003cem\u003eDendrobeania\u003c/em\u003e sp., \u003cem\u003eSchizoporella obesa\u003c/em\u003e and other schizoporellids that appeared on the experimental plates in 2005 were not identified in 2020. Eight taxa were recorded only on the panels recovered in 2020 (not seen in 2005): \u003cem\u003eDoryporella spathulifera\u003c/em\u003e, \u003cem\u003eDiplosolen arctica\u003c/em\u003e, \u003cem\u003eTricellaria arctica\u003c/em\u003e, \u003cem\u003eTricellaria gracilis\u003c/em\u003e, \u003cem\u003eStomachetosella cruenta\u003c/em\u003e, \u003cem\u003eSpirorbis tridentatus\u003c/em\u003e, a dark type of \u003cem\u003eTegella\u003c/em\u003e sp. and Scrupocellidae individuals. Datasets from both years had 34 taxa in common. In 2020 \u003cem\u003eHarmeria scutulata\u003c/em\u003e (ANOSIM between years R\u0026thinsp;=\u0026thinsp;0.44) and \u003cem\u003eSemibalanus balanoides\u003c/em\u003e (R\u0026thinsp;=\u0026thinsp;0.82) were less abundant, whilst cyclostome and cheilostome ancestrulae (R\u0026thinsp;=\u0026thinsp;0.72 and 0.57 respectively), \u003cem\u003eMicroporella arctica\u003c/em\u003e (R\u0026thinsp;=\u0026thinsp;0.54), \u003cem\u003eTegella arctica\u003c/em\u003e (R\u0026thinsp;=\u0026thinsp;0.63), and \u003cem\u003eCirceis\u003c/em\u003e sp. (R\u0026thinsp;=\u0026thinsp;0.73) were more abundant than in 2005.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn 2005, ancestrula of Cyclostomata (134.3 per 100 cm\u003csup\u003e2\u003c/sup\u003e), \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ebalanoides\u003c/em\u003e (153.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e), \u003cem\u003eCirceis\u003c/em\u003e sp. (125.3 per 100 cm\u003csup\u003e2\u003c/sup\u003e) and \u003cem\u003eP\u003c/em\u003e. \u003cem\u003evitrea\u003c/em\u003e (121.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e) were the most abundant at S1 7 m, while \u003cem\u003eH\u003c/em\u003e. \u003cem\u003escutulata\u003c/em\u003e (100.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e), \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ebalanoides\u003c/em\u003e (157.3 per 100 cm\u003csup\u003e2\u003c/sup\u003e), \u003cem\u003eCirceis\u003c/em\u003e sp. (346.7 per 100 cm\u003csup\u003e2\u003c/sup\u003e) and \u003cem\u003eP\u003c/em\u003e. \u003cem\u003evitrea\u003c/em\u003e (130.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e) at S2 shallow. In 2020 at the shallow study sites, two taxa of the overall highest abundance (per 100 cm\u003csup\u003e2\u003c/sup\u003e) were recorded; \u003cem\u003eP\u003c/em\u003e. \u003cem\u003evitrea\u003c/em\u003e (502.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e) at S1 and \u003cem\u003eCirceis\u003c/em\u003e sp. at (527.0 per 100 cm\u003csup\u003e2\u003c/sup\u003e) at S2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eApart from S2 7 m, a significant increase in mean values of species richness and abundance per plate (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) in 2020 were observed at both stations, and depths. Species richness and abundance were the most variable at S1 (13 m) in 2020. The highest species richness was reached at the S2 shallow (7 m) station in 2005. The highest abundance was noted at S1 shallow in 2020. It was also at this station that the biggest difference (more than double) in total abundance between 2005 (693.7 per 100 cm\u003csup\u003e2\u003c/sup\u003e) and 2020 (1545.7 per 100 cm\u003csup\u003e2\u003c/sup\u003e) was observed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe sample from S2 at 15 m in 2005 had the lowest value of the Pielou (0.77) index (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Those replicates were highly dominated by \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ebalanoides\u003c/em\u003e individuals (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e; Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Assemblages at the S2 at 7 m did not significantly differ between years aside from it all other pairs of site and depth were significantly different between years based on the Wilcoxon test (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05; Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Samples from S1 (13 m) collected in 2020 reached the highest values of the Shannon\u003cb\u003e-\u003c/b\u003eWiener diversity index (3.03).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of the Wilcoxon paired test displaying differences between the taxonomic composition of samples from 2005 and 2020. Significant values in bold (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eS1 2005 7m\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS1 2005 13m\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eS2 2005 7m\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eS2 2005 15m\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS1 2020 7m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e0.01\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS1 2020 13m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS2 2020 7m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e0.02\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS2 2020 15m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.00\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePielou\u0026rsquo;s (J\u0026rsquo;) and Shannon- Wiener\u0026rsquo;s diversity (H\u0026rsquo;) indices for averaged data from three replicate samples\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eS1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003eS2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e7m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e13m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003e7m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e15m\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eJ\u0026rsquo;\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eH\u0026rsquo;\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThere were significant differences between 2005 and 2020 in species richness, abundance and assemblage structure based on the PERMANOVA analysis (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The \u0026lsquo;year\u0026rsquo; was the most influential factor differentiating the structure of the assemblage (28.54%). Whereas for taxa richness and abundance the \u0026lsquo;depth\u0026rsquo; factor described most of the variability between samples (19.85% and 30.12%, respectively) and for both of them \u0026lsquo;site\u0026rsquo; was not statistically significant. Only in the case of assemblage structure did all of the study factors have a significant influence.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThree-way PERMANOVA analysis for differences among sites, years and depths based on species richness, abundance and assemblage structure. Raw data were square root transformed. Significant values mean p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003especies richness\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eabundance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003eassemblage structure\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efactors\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePseudo-F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCV [%]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePseudo-F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eCV [%]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ePseudo-F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eCV [%]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esite\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.389\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.737\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e4.88\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.000\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e4.33\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyear\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e6.78\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.010\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e12.12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e13.02\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e24.24\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e26.58\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.000\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e28.54\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003edepth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e10.47\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e19.85\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e15.93\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.004\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e30.12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e13.16\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.000\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e13.57\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esite x year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.948\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.688\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e3.92\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.000\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e6.51\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esite x depth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4.88\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.038\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e16.26\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.917\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e6.40\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e12.05\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyear x depth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4.70\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.035\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e15.52\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e3.91\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.005\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e6.50\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esite x year x depth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.746\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.164\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e4.39\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e15.12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe underlying structure of the epibenthic assemblage overgrowing the settlement plates was also investigated using LINKTREE analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). The splits in the cluster were based on the abundances of taxa differentiating the samples (cut-off values added in brackets). Two of the five splits were significant. The first split (A) was based on the levels of abundance of several taxa \u0026ndash; \u003cem\u003eElectra arctica\u003c/em\u003e (\u0026gt;\u0026thinsp;2.67\u0026thinsp;\u0026lt;\u0026thinsp;0.333), \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ebalanoides\u003c/em\u003e (\u0026gt;\u0026thinsp;235\u0026thinsp;\u0026lt;\u0026thinsp;157), Tubuliporidae indet. (\u0026lt;\u0026thinsp;0 \u0026gt;\u0026thinsp;3.67), ancestrula Cyclostomatida (\u0026lt;\u0026thinsp;18.7\u0026thinsp;\u0026gt;\u0026thinsp;65.7), \u003cem\u003eCirceis\u003c/em\u003e sp. (\u0026lt;\u0026thinsp;57.3\u0026thinsp;\u0026gt;\u0026thinsp;119), \u003cem\u003eCallopora lineata\u003c/em\u003e (\u0026lt;\u0026thinsp;0 \u0026gt;\u0026thinsp;3.67), Spirorbinae indet. (\u0026lt;\u0026thinsp;1 \u0026gt;\u0026thinsp;9) or \u003cem\u003eSpirorbis\u003c/em\u003e sp./\u003cem\u003eBushiella\u003c/em\u003e sp./\u003cem\u003ePilleolaria\u003c/em\u003e sp. complex (\u0026lt;\u0026thinsp;0.667\u0026thinsp;\u0026gt;\u0026thinsp;12.3), \u003cem\u003eCirceis spirillum\u003c/em\u003e (\u0026lt;\u0026thinsp;0 \u0026gt;\u0026thinsp;2), \u003cem\u003eCallopora\u003c/em\u003e sp. (\u0026lt;\u0026thinsp;1.33\u0026thinsp;\u0026gt;\u0026thinsp;2.33), \u003cem\u003eP\u003c/em\u003e. \u003cem\u003evitrea\u003c/em\u003e (\u0026lt;\u0026thinsp;2 \u0026gt;\u0026thinsp;22.3), ancestrula Cheilostomatida (\u0026lt;\u0026thinsp;1 \u0026gt;\u0026thinsp;3.33) or \u003cem\u003eMyriozella crustacea\u003c/em\u003e (\u0026lt;\u0026thinsp;0.333\u0026thinsp;\u0026gt;\u0026thinsp;0.667) and it differentiated sample from S2 (12 m) collected in 2005 from the remaining samples. The next significant split (B) differentiated two groups. This split was based on the abundance of a few taxa \u0026ndash; \u003cem\u003eCylindroporella tubulosa\u003c/em\u003e (\u0026lt;\u0026thinsp;0.667\u0026thinsp;\u0026gt;\u0026thinsp;4.67), Spirorbinae indet. (\u0026lt;\u0026thinsp;19.3\u0026thinsp;\u0026gt;\u0026thinsp;33.7), ancestrula Cheilostomatida (\u0026lt;\u0026thinsp;8.67\u0026thinsp;\u0026gt;\u0026thinsp;17.7) or \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ebalanoides\u003c/em\u003e (\u0026gt;\u0026thinsp;51.7\u0026thinsp;\u0026lt;\u0026thinsp;15). Split C grouped the rest of the samples from 2005. All samples collected in 2020 were under the splits D and E. Although insignificant, the sample from S1 shallow (6 m) separated from the other samples.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eOverall, the results showed significant differences between samples collected in 2005 and 2020. Although, there were 5 lost and 8 gained taxa in 2020 none of those significantly differentiated the samples in the cluster (apart from the outlying sample from S2 at 15 m in 2005). The \u0026lsquo;year\u0026rsquo; factor had a significant influence on assemblage composition within samples.\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eDespite dominating polar species numbers and being key vulnerable marine environment indicators, benthos are difficult to robustly, repeatedly sample at remote, high latitude sites. Revisiting the same Spitsbergen study area after 15 years with the exact methodology enabled us to detect changes in the structure of encrusting assemblages, mostly realised in a species dominance shift. Five taxa found in 2005 did not occur in 2020, but eight new ones were identified in samples from 2020. There are few comparable exact revisits using similar apparatus, protocols, site and target taxa (but e.g. for Antarctica see Dayton (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1989\u003c/span\u003e) or Souster (\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e2018\u003c/span\u003e)). Some detection of biota differences across samples in space or time is expected, so of key importance is the extent of differences and what their drivers are. Environmental differences revealed by satellite data and supported by other studies in the Isfjorden region (e.g. Pavlov et al. \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Skogseth et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Bloshkina et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), we argue that the shift in the structure of the epibenthic assemblage reported in this study could be the result of changes in the temperature conditions within the fjord and other parameters induced by climate change.\u003c/p\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Environmental conditions\u003c/h2\u003e \u003cp\u003eMonthly surface temperatures in the Isfjorden area (including temperatures of water and ice, if it was present) have significantly increased throughout the whole year, but especially within the winter months (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The most drastic change in surface temperature over Isfjorden was recorded in March with mean values in 2005 of -18.3\u0026deg;C compared to -4.4\u0026deg;C in 2020. However, the temperature near the shallow sea bed was more constant. We can observe a relatively warm summer in 2019 with maximal temperatures at the bottom reaching almost 10.0\u0026deg;C at a depth of 7 meters, but also a relatively cold winter with averages in March of 2020 around \u0026minus;\u0026thinsp;1.9\u0026deg;C (Moreno et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). There has been a pronounced warming detected within the fjord with a growing presence of Atlantic water also in the bottom layers with temperatures above 3\u0026deg;C starting from 2013 onwards (Bloshkina et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In the summer of 2014 temperatures in Isfjorden were especially high (Skogseth et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) and Atlantic water has been recorded even in Billefjorden (Bloshkina et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). There were detectable temperature differences between years and signs of marine heat spikes occurring in the Arctic with increasing frequency (Beszczynska-Mӧller et al. 2012; Promińska et al. 2017; Skogseth et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Mohamed et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Huang et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Aside from the growing temperatures, the Arctic is also dealing with an increasing melting of sea ice, with a loss of ~\u0026thinsp;10% per decade especially during winter occurring since 1979 (Onarheim et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Muckenhuber et al. 2016) and glaciers, with mass loss of 401\u0026thinsp;\u0026plusmn;\u0026thinsp;24 kg m\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e a\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e over Svalbard between 2010 and 2017 (Tepes et al. \u003cspan citationid=\"CR73\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). A significant decline in the presence of sea ice cover in Isfjorden has been observed since the beginning of this century, with substantial strengthening of this trend since 2006 (Muckenhuber et al. 2016). As a result of this process, more sea surface is accessible for phytoplankton blooms therefore, the net primary production in the Arctic region is reportedly continuously increasing (Arrigo and van Dijken, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Frey et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Under such environmental forcing, we expected the local ecosystem to have undergone noticeable changes.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Assemblage structure shift\u003c/h2\u003e \u003cp\u003eOur study documents a clear difference in the structure of the hard-bottom encrusting community between 2005 and 2020. Repeat visits to a polar fjord in Antarctica detected both an assemblage shift and identified sedimentation as a driver of this (Sahade et al. 2015). In the Arctic, several distinct changes have already been reported within other biotic components of marine ecosystems. An overall shift in hard-bottom benthic composition was already reported by Kortsch et al. (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) around the end of the last century in Kongsfjorden. Their 30-year-long study found an abrupt increase in macroalgae (a shift from the dominance of red calcareous algae \u003cem\u003eLithothamnion\u003c/em\u003e sp. to filamentous brown algae \u003cem\u003eSacchoriza dermatodea\u003c/em\u003e) and a concurrent increase in diversity and major change of invertebrate assemblage (shift from the dominance of sea anemones to sea urchins). Weslawski et al. (\u003cspan citationid=\"CR79\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) reported an increase in intertidal macrobenthos diversity in the southern Svalbard (Sorkappland and Hornsund) from 19 to 43 taxa between 1988 and 2008 (using 20 cm x 20 cm frames at low tide). Newly recorded species in that study were mostly of boreal and arctic-boreal origin. In our study, after 15 years, we similarly found significant differences in the 2020 assemblage from the initial one, yet not entirely unrecognisable. All taxa recovered in both years and identified to species level have been reported in the Svalbard area (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). However, in the early stages of the sample analysis, we observed obvious shifts in the abundances of a few dominant taxa. This included a major drop in the abundance of \u003cem\u003eHarmeria scutulata\u003c/em\u003e and \u003cem\u003eSemibalanus balanoides\u003c/em\u003e between 2005 and 2020 and a simultaneous increase in the number of individuals of \u003cem\u003eCirceis\u003c/em\u003e sp., Spirorbinae indet. and cheilostome and cyclostome ancestrulae. From both groups \u0026ndash; bryozoans and serpulids \u0026ndash; many species are recognised as opportunistic and reported to be amongst the pioneer colonisers of a newly available hard substrate (Barnes, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1996\u003c/span\u003e; Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Wisshak et al. 2021). \u003cem\u003eHarmeria scutulata\u003c/em\u003e was an important species within the shallow coastal Arctic assemblages at the beginning of the century often accounting for more than 50% of bryozoan colonies in assemblages (Barnes \u0026amp; Kuklinski \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2005\u003c/span\u003e, Kuklinski and Taylor, 2006). In the current study, the maximum contribution of \u003cem\u003eH\u003c/em\u003e. \u003cem\u003escutulata\u003c/em\u003e to the bryozoan assemblage on the experimental plates reached at most 33% in 2005 at the S2 shallow station and was below 1% at the same station in 2020. However, in 2014/2015 it was still one of the most frequently recorded pioneers collected in Gronfjorden (the outmost inlet of Isfjorden) (Evseeva and Dvoretsky, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), and in the eastern area of the Kola Peninsula (Evseeva et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). On the south bank of Isfjorden \u003cem\u003eH\u003c/em\u003e. \u003cem\u003escutulata was\u003c/em\u003e also very abundant until 2014, but has become more scarce since (Sowa, unpubl. data). Like most pioneers this species is a poor spatial competitor for substrate, losing around 70% of species interactions (Barnes and Kuklinski, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Its distribution has been reported to be circumpolar and reaches at most down to Kodiak Island in Alaska (Kuklinski and Taylor, 2006). The acorn barnacle \u003cem\u003eS. balanoides\u003c/em\u003e has a wide boreo-arctic distribution in the North Atlantic, with an established population in the Svalbard region. It has been reported as a sentinel of climate change as its biogeographic range and reproductive success is tightly linked to temperature (Herrera et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Walczynska et al. 2019). Studies held in the European intertidal have already shown contraction in the southern extent of this species by 300 km and drops in abundance in areas with warm winters (\u0026gt;\u0026thinsp;10\u0026deg;C) due to inhibited reproduction (Barnes, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1963\u003c/span\u003e; Wethey and Woodin, \u003cspan citationid=\"CR80\" class=\"CitationRef\"\u003e2008\u003c/span\u003e; Rhiannon and Hilbish, 2014). Jones et al. (\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) reported a contraction of the southern distribution extent by 350 km on the eastern coast of the United States but concluded it to be driven by summer heat death rather than winter cold limitation of reproduction as suggested by Wethey and Woodin (\u003cspan citationid=\"CR80\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) on the other side of the Atlantic. Short-term warm conditions can also influence the abundance of barnacles, and their temperature dependence leads to significant annual fluctuations in recruitment (Walczynska et al. 2019; Rhiannon and Hilbish, 2014). As it is a long-lived species, it is also possible that reproduction might not occur every year (Walczynska et al. 2019).\u003c/p\u003e \u003cp\u003eA few of the noted taxa displayed an increase in abundance between the 2005 and 2020 samples. Three bryozoan species were reported to have reached higher abundances \u0026ndash; \u003cem\u003eCylindroporella tubulosa\u003c/em\u003e, \u003cem\u003eMicroporella arctica\u003c/em\u003e and \u003cem\u003eTegella arctica\u003c/em\u003e, all typical for the Svalbard area and noted in the region previous to this study on both natural and artificial substrates (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). This could be explained by the simultaneous decrease in the presence of \u003cem\u003eH\u003c/em\u003e. \u003cem\u003escutulata\u003c/em\u003e leaving more space for other taxa. On the other hand, those species may be more resilient to changes in the environment in comparison to (the previously abundant) \u003cem\u003eH\u003c/em\u003e. \u003cem\u003escutulata\u003c/em\u003e. Notably, there was a large number of juveniles (organisms younger than three months) \u0026ndash; of both bryozoans and serpulids (Sowa, pers obs based on Sowa et al. \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). That could be an indication of greater reproductive success in the spring and summer of 2020 or either a change in the timing of larvae release or the length of the pelagic stage. Coincidentally, in 2020 high cumulative intensity and duration of marine heatwaves were observed over the Barents Sea (Mohamed et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) which could consequently influence levels of primary production. However, serpulids have non-feeding types of larvae (lecithotrophic), which allows them to be released independently from primary production peaks (Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Ushakova, \u003cspan citationid=\"CR74\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Polychaete larvae were identified in the water column there throughout spring and summer (Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). However, recruitment on experimental plates has been reported to occur throughout the whole year (Kuklinski et al, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Meyer et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Sowa et al. \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Silberberger et al. (\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) reported the presence of bryozoan larvae throughout spring and summer in the sub-Arctic area (northern Norway). In the study of Kuklinski et al. (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) in Adventfjorden (an Isfjorden inlet fiord) peaks occurred between April and June with delayed recruitment on the experimental plates. Bryozoans possess lecitotrophic or planktotrophic larvae depending on the species (St\u0026uuml;bner et al. \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). The duration of presence in the water column is about two months for feeding larvae, but less (even just a few hours) for the non-feeding type which usually remains close to the sea bottom and settles much faster and thus is rarely identified in plankton samples (Kluge, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1975\u003c/span\u003e; McKinney and Jackson, 1989; Temkin and Zimmer, \u003cspan citationid=\"CR72\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Larval release is driven by a variety of factors, for some lecithotrophic larvae the main cue is light (i.e. being released at dawn), although this might be very different in the Arctic region with the presence of polar day. They also initially display photopositive behaviour which may aid with better dispersal in that short window of time (Temkin and Zimmer, \u003cspan citationid=\"CR72\" class=\"CitationRef\"\u003e2002\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the summer of 2019, the highest maximal bottom water temperatures (at depths of 7 m and 14\u0026thinsp;\u0026plusmn;\u0026thinsp;1 m) were noted (from a period between August 2006 and July 2022) as well as a wide range of logged temperatures in winter (between 2\u0026deg;C in December 2019 and down to -1.7\u0026deg;C until April 2020, see Moreno et al. (\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). In 2020 there were intense marine heatwaves noted in the Barents Sea region (Mohamed et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). This seems likely to influence early onset release of larvae in the summer of 2020 that had enough time to recruit by the time of retrieval of the experimental plates. There is prior evidence that increasing temperatures in the Arctic region could lead to a shortening of larval development and quicker settlement (O\u0026rsquo;Connor et al. 2007).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e4.3 New arrivals?\u003c/h2\u003e \u003cp\u003eThe handful of new taxa that were identified on the plates from 2020 comprised of four Arctic species \u0026ndash; \u003cem\u003eDoryporella spathulifera\u003c/em\u003e, \u003cem\u003eDiplosolen arctica\u003c/em\u003e, \u003cem\u003eTricellaria arctica\u003c/em\u003e, \u003cem\u003eTricellaria gracilis\u003c/em\u003e (Kluge, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1975\u003c/span\u003e), one Arctic-boreal \u0026ndash; \u003cem\u003eStomachetosella cruenta\u003c/em\u003e (Kluge, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1975\u003c/span\u003e), one with a wider distribution, recorded even in Spain \u0026ndash; \u003cem\u003eSpirorbis tridentatus\u003c/em\u003e (Rzhavsky et al. \u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), but previously recorded with particularly high abundance in Isfjorden in 2002 (Barnes and Kuklinski, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2005\u003c/span\u003e) and 2010 (Balazy and Kuklinski, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), and one family and one genus previously recorded in the Svalbard area - Scrupocellidae and \u003cem\u003eTegella\u003c/em\u003e sp. differentiated by us as dark type (Kuklinski et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Meyer et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Of the above-mentioned species all were identified in Svalbard fjords either before 2005 or between 2005 and 2020 in previous reports (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Based on these data we can conclude that although the composition of the assemblage was significantly different in 2020, the species composition was still representative of that hitherto described for the Svalbard region. Some of the species, \u003cem\u003eD\u003c/em\u003e. \u003cem\u003espathulifera\u003c/em\u003e, \u003cem\u003eS\u003c/em\u003e. \u003cem\u003ecruenta\u003c/em\u003e and \u003cem\u003eT\u003c/em\u003e. \u003cem\u003egracilis\u003c/em\u003e, were reported in the samples collected by Evseeva and Dvoretsky (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) around Franz Josef Land between 2006 and 2008 but were low in biomass. Their absence in our samples from 2005 could be a result of natural fluctuations (for example see 5 years long, a monthly record of species fluctuations at the same site by Watson and Barnes \u003cspan citationid=\"CR78\" class=\"CitationRef\"\u003e2004\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e4.4 Structure under factors\u003c/h2\u003e \u003cp\u003eIn this study, in testing the effects of different factors, beyond investigating the influence of time (\u0026lsquo;year\u0026rsquo;) we also included factors related to depth and geographical location (\u0026lsquo;site\u0026rsquo; and \u0026lsquo;depth\u0026rsquo;; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Considering the overall assemblage structure all of the factors and their interactions were statistically significant \u0026ndash; the \u0026lsquo;year\u0026rsquo; factor explaining most of the differentiation between samples (28.5%). However, for species richness and abundance, not all factors were significant, and the \u0026lsquo;depth\u0026rsquo; factor was the most important for both, whereas the \u0026lsquo;site\u0026rsquo; was not statistically significant. The insignificance of the \u0026lsquo;site\u0026rsquo; factor could be explained by the short distances between study sites, which were approximately only two nautical miles apart. Although the depth difference was not large (~\u0026thinsp;7 m between strata) the key difference between them was the presence of dense kelp forests around the shallower study sites. The presence of kelp could have acted as a stabiliser for the overall conditions by limiting the water movement but also provided an additional source of food (Balazy and Kuklinski, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) and habitat complexity. The kelps themselves are predicted to experience range shifts under different climate scenarios. Assis et al. (2017) predicted the potential loss of \u003cem\u003eLaminaria solidungula\u003c/em\u003e, an endemic, stenothermic species (Lebrun et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) in the southwest area of Svalbard with simultaneous expansion of \u003cem\u003eLaminaria hyperborean\u003c/em\u003e, \u003cem\u003eL\u003c/em\u003e. \u003cem\u003edigitata\u003c/em\u003e and \u003cem\u003eSaccorhiza dermatodea\u003c/em\u003e around parts of the archipelago (two other species of kelp \u0026ndash; \u003cem\u003eAlaria esculenta\u003c/em\u003e and \u003cem\u003eSaccharina latissima\u003c/em\u003e remaining stable). For \u003cem\u003eL\u003c/em\u003e. \u003cem\u003edigitata\u003c/em\u003e an increase of biomass up to four times has already been recorded (Lebrun et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Although the predictions are rather optimistic for the kelps in the Arctic in the sense of biomass and distribution range increase, the composition of species will experience change that will most likely affect the associated fauna (Lebrun et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The number of taxa was rather similar between the depths at the same sites (besides samples from S2 in 2005 which had very low recruitment) but the average abundance of individual recruits was higher in samples from shallower depth (7m).\u003c/p\u003e \u003cp\u003eObtained results showed significant differences between assemblages over the 15 years supporting the hypothesis of the study. The most influential changes observed were the shifts in dominance suggesting a reorganisation of the assemblage rather than a change in the taxonomic pool. This agrees with the nature of the shift observed for hard bottom macrofauna by Kortsch et al. (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) in Spitsbergen fjords. On the other hand, the Arctic has been under climate change forcing long before the start of our experiment in 2004. Beszczynska-Mӧller et al. (2012) reported on a warm anomaly in the Fram Strait in 1999/2000 and Bloshkina et al. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) described increasing proportion and further extension of Atlantic waters in the bottom layer from 2003 onwards. Within almost a century (1912\u0026ndash;2009) Isfjorden experienced 1.9\u0026deg;C of overall warming (Pavlov et al. \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Thus, the results obtained in this study may showcase the already altered state of the hard-bottom assemblage. Nonetheless, they indicate the direction of ongoing change and provide a crucial reference point for comparison in the future.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSpecies identified in this study compared to the species lists from other studies conducted in the Svalbard area\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003etime/area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eup to 2000\u003c/p\u003e \u003cp\u003eSvalbard\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2002 Kongsfjord\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2002 Hornsund\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2002 Isfjorden\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2007 Adventfjorden\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2014/2015 Gronefjorden\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2015 Svalbard\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2017 Isfjorden\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esource\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePalerud et al. (\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e2004\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eKuklinski and Barnes (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2005\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBarnes and Kuklinski (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2005\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eKuklinski et al. (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2013\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eEvseeva et al. (2023)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMeyer et al. (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSowa et al. (\u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2023\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eArctonula arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCallopora craticula\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCallopora lata\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCallopora lineata\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCelleporella hyalina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCribrilina annulata\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCylindroporella tubulosa\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eDoryporella spathulifera\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eDiplosolen arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eElectra arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eHarmeria scutulata\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eHippodiplosia obesa\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eHippothoa arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eMicroporella arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eMyriozella crustacea\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eRaymondcia rigida\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSmittina minuscula\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eStomachetosella cruenta\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTegella arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTegella armifera\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTricellaria arctica\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTricellaria gracilis\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTubulipora flabellaris\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSemibalanus balanoides\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003enot included\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003enot included\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003enot included\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSpirorbis tridenatus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCirceis spirillum\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eParadexiospira vitrea\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eChitinopoma serrula\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eX\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of interests\u003c/strong\u003e Authors declare no conflict of interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData/Code availability\u0026nbsp;\u003c/strong\u003eThe datasets generated during and/or analysed during the current study are not publicly available but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s contribution\u0026nbsp;\u003c/strong\u003eAll authors contributed to the study conception and design. Field campaigns were performed by Balazy Piotr, Chelchowski Maciej. Formal analysis and investigation were performed by Sowa Anna. The first draft of the manuscript was written by Sowa Anna and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Work on the manuscript was supervised by Iglikowska Anna and Kotwicki Lech\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSurface temperature and sea ice extent data were provided by DMI and the Copernicus CMEMS project.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAl-Habahbeh AK, Kortsch S, Bluhm BA, Beuchel F, Gulliksen B, Ballantine C, Domiziana C, Primicerio R (2020) Arctic coastal benthos long-term responses to perturbations under climate warming. Philosophical Trans Royal Soc A 378(2181):20190355\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArrigo KR, van Dijken GL (2015) Continued increases in Arctic Ocean primary production. Prog Oceanogr 136:60\u0026ndash;70\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAssis J, Ara\u0026uacute;jo MB, Serr\u0026atilde;o EA (2018) Projected climate changes threaten ancient refugia of kelp forests in the North Atlantic. Glob Change Biol 24(1):e55\u0026ndash;e66\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBalazy P, Kuklinski P (2017) Arctic field experiment shows differences in epifaunal assemblages between natural and artificial substrates of different heterogeneity and origin. J Exp Mar Biol Ecol 486:178\u0026ndash;187\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes DKA (1996) Low levels of colonisation in Antarctica: the role of bryozoans in early community development. Bryozoans in space and time. National Institute of Water and Atmospheric Research, pp 19\u0026ndash;28\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes DKA (2015) Marine colonization and biodiversity at Ascension Island and remote islands. J Mar Biol Assoc U K 97:771\u0026ndash;782\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes DKA, Kuklinski P (2003) High polar spatial competition: extreme hierarchies at extreme latitude. Mar Ecol Prog Ser 259:17\u0026ndash;28\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes DKA, Kukliński P (2005) Low colonisation on artificial substrata in arctic Spitsbergen. Polar Biol 29:65\u0026ndash;69\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes H (1963) Light, temperature and the breeding of \u003cem\u003eBalanus balanoides\u003c/em\u003e. J Mar Biol Association United Kingd 43(3):717\u0026ndash;727\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeisiegel K, Darr A, Gogina M, Zettler ML (2017) Benefits and shortcomings of non-destructive benthic imagery for monitoring hard-bottom habitats. Mar Pollut Bull 121(1\u0026ndash;2):5\u0026ndash;15\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeszczynska-M\u0026ouml;ller A, Fahrbach E, Schauer U, Hansen E (2012) Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997\u0026ndash;2010. ICES J Mar Sci 69(5):852\u0026ndash;863\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeuchel F, Gulliksen B (2008) Temporal patterns of benthic community development in an Arctic fjord (Kongsfjorden, Svalbard): results of a 24-year manipulation study. Polar Biol 31(8):913\u0026ndash;924\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeuchel F, Gulliksen B, Carroll ML (2006) Long-term patterns of rocky bottom macrobenthic community structure in an Arctic fjord (Kongsfjorden, Svalbard) in relation to climate variability (1980\u0026ndash;2003). J Mar Syst 63(1\u0026ndash;2):35\u0026ndash;48\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBloshkina EV, Pavlov AK, Filchuk K (2021) Warming of Atlantic Water in three west Spitsbergen fjords: recent patterns and century-long trends. Polar Res, 40\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBowden DA, Clarke A, Peck LS, Barnes DKA (2006) Antarctic sessile marine benthos: colonisation and growth on artificial substrata over three years. Mar Ecol Prog Ser 316:1\u0026ndash;16\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChan FT, Stanislawczyk K, Sneekes AC, Dvoretsky A, Gollasch S, Minchin D, Bailey SA (2019) Climate change opens new frontiers for marine species in the Arctic: Current trends and future invasion risks. Glob Change Biol 25(1):25\u0026ndash;38\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eClarke KR, Somerfield PJ, Gorley RN (2008) Testing of null hypotheses in exploratory community analyses: similarity profiles and biota-environment linkage. J Exp Mar Biol Ecol 366:56\u0026ndash;69\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eConlan KE, Kvitek RG (2005) Recolonization of soft-sediment ice scours on an exposed Arctic coast. Mar Ecol Prog Ser 286:21\u0026ndash;42\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCottier FR, Nilsen F, Inall ME, Gerland S, Tverberg V, Svendsen H (2007) Wintertime warming of an Arctic shelf in response to large-scale atmospheric circulation. Geophys Res Lett, 34(10)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDalpadado P, Ingvaldsen RB, Stige LC, Bogstad B, Knutsen T, Ottersen G, Ellertsen B (2012) Climate effects on Barents Sea ecosystem dynamics. ICES J Mar Sci 69(7):1303\u0026ndash;1316\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDayton PK (1989) Interdecadal variation in an Antarctic sponge and its predators from oceanographic climate shifts. Science 245:1484\u0026ndash;1496\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEvseeva OY, Dvoretsky AG (2023) Shallow-water bryozoan communities in a glacier fjord of West Svalbard, Norway: Species composition and effects of environmental factors. Biology 12(2):185\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEvseeva OY, Dvoretsky AG (2024) Bryozoan communities off Franz Josef Land (northern Barents Sea, Russia): Distribution patterns and environmental control. J Mar Syst 242:103944\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEvseeva OY, Ishkulova TG, Dvoretsky AG (2022) Environmental drivers of an intertidal bryozoan community in the Barents Sea: A case study. Animals 12(5):552\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFossheim M, Primicerio R, Johannesen E, Ingvaldsen RB, Aschan MM, Dolgov AV (2015) Recent warming leads to a rapid borealization of fish communities in the Arctic. Nat Clim change 5(7):673\u0026ndash;677\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFraser NJ, Skogseth R, Nilsen F, Inall ME (2018) Circulation and exchange in a broad Arctic fjord using glider-based observations. Polar Res 37(1):1485417\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFrey KE, Comiso JC, Cooper LW, Grebmeier JM, Stock LV (2021) Arctic ocean primary productivity: The response of marine algae to climate warming and sea ice decline. Arctic Report Card\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFriedlander AM, Ballesteros E, Adler AM, Goodell W, Jenkinson R, Knopp JA, Sala E (2023) Shallow subtidal marine benthic communities of Nachvak Fjord, Nunatsiavut, Labrador: A glimpse into species composition and drivers of their distribution. PLoS ONE, 18(11), e0293702\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026oacute;rska B, Gromisz S, Legeżyńska J, Soltwedel T, Włodarska-Kowalczuk M (2022) Macrobenthic diversity response to the atlantification of the Arctic Ocean (Fram Strait, 79\u0026deg; N)\u0026ndash;A taxonomic and functional trait approach. Ecol Ind 144:109464\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGray JS, Christie H (1983) Predicting long-term changes in marine benthic communities. Mar Ecol progress Ser Oldendorf 13(1):87\u0026ndash;94\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHerrera M, Wethey DS, V\u0026aacute;zquez E, Macho G (2019) Climate change implications for reproductive success: temperature effect on penis development in the barnacle Semibalanus balanoides. Mar Ecol Prog Ser 610:109\u0026ndash;123\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang B, Wang Z, Yin X, Arguez A, Graham G, Liu C, Zhang HM (2021) Prolonged marine heatwaves in the Arctic: 1982\u0026thinsp;\u0026ndash;\u0026thinsp;2020. Geophys Res Lett, 48(24), e2021GL095590.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJones SJ, Southward AJ, Wethey DS (2012) Climate change and historical biogeography of the barnacle Semibalanus balanoides. Glob Ecol Biogeogr 21(7):716\u0026ndash;724\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJord\u0026agrave;-Molina \u0026Egrave;, Renaud PE, Silberberger MJ, Sen A, Bluhm BA, Carroll ML, Reiss H (2023) Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord. Mar Environ Res, 106046\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKennedy EV, Ordo\u0026ntilde;ez A, Lewis BE, Diaz-Pulido G (2017) Comparison of recruitment tile materials for monitoring coralline algae responses to a changing climate. Mar Ecol Prog Ser 569:129\u0026ndash;144\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlekowski RZ, Weslawski JM (1991) Atlas of the marine fauna of southern Spitsbergen, Vol. 2(part 3), Institute of Oceanography, Poland, 152 pp\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKluge GA (1975) Bryozoa of the northern seas of the USSR. Keys on the fauna of the USSR published by the Zoological Institute. Acad Sci USSR 76:1\u0026ndash;711\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKortsch S, Primicerio R, Beuchel F, Renaud PE, Rodrigues J, L\u0026oslash;nne OJ, Gulliksen B (2012) Climate-driven regime shifts in Arctic marine benthos. \u003cem\u003eProceedings of the National Academy of Sciences\u003c/em\u003e, \u003cem\u003e109\u003c/em\u003e(35), 14052\u0026ndash;14057\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKotwicki L, Weslawski JM, Włodarska-Kowalczuk M, Mazurkiewicz M, Wenne R, Zbawicka M, Olenin S (2021) The re-appearance of the Mytilus spp. complex in Svalbard, Arctic, during the Holocene: The case for an arrival by anthropogenic flotsam. Glob Planet Change 202:103502\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKuklinski P, Balazy P, Porter J, Loxton J, Ronowicz M, Sokołowski A (2022) Experimental apparatus for investigating colonization, succession and related processes of rocky bottom epifauna. Cont Shelf Res 233:104641\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKuklinski P, Barnes DKA (2005) Bryodiversity on coastal boulders at Spitsbergen. Bryozoan studies 2004. CRC, pp 171\u0026ndash;182\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKuklinski P, Berge J, McFadden L, Dmoch K, Zajaczkowski M, Nyg\u0026aring;rd H, Piwosz K, Tatarek A (2013) Seasonality of occurrence and recruitment of Arctic marine benthic invertebrate larvae in relation to environmental variables. Polar Biol 36(4):549\u0026ndash;560\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLantuit H, Overduin PP, Couture N, Wetterich S, Ar\u0026eacute; F, Atkinson D, Vasiliev A (2012) The Arctic coastal dynamics database: A new classification scheme and statistics on Arctic permafrost coastlines. Estuaries Coasts 35:383\u0026ndash;400\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLebrun A, Comeau S, Gazeau F, Gattuso JP (2022) Impact of climate change on Arctic macroalgal communities. Glob Planet Change 219:103980\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcKinney FK, Jackson JB (1991) Bryozoan evolution. University of Chicago Press\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeyer KS, Sweetman AK, Kuklinski P, Leopold P, Vogedes D, Berge J, Griffiths C, Young CM, Renaud PE (2017) Recruitment of benthic invertebrates in high Arctic fjords: Relation to temperature. depth. and season. Limnol Oceanogr 62(6):2732\u0026ndash;2744\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohamed B, Nilsen F, Skogseth R (2022) Marine heatwaves characteristics in the barents sea based on high resolution satellite data (1982\u0026ndash;2020). Front Mar Sci 9:821646\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoreno B, Sowa A, Reginia K, Balazy P, Chelchowski M, Ronowicz M, Kuklinski P (2024) Sea water temperature and light intensity at high-Arctic subtidal shallows\u0026ndash;16 years perspective. Sci Data 11(1):227\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNicoletti L, Marzialetti S, Paganelli D, Ardizzone GD (2007) Long-term changes in a benthic assemblage associated with artificial reefs. Hydrobiologia 580(1):233\u0026ndash;240\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNilsen F, Cottier F, Skogseth R, Mattsson S (2008) Fjord\u0026ndash;shelf exchanges controlled by ice and brine production: the interannual variation of Atlantic Water in Isfjorden. Svalbard Cont Shelf Res 28(14):1838\u0026ndash;1853\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eO'Connor MI, Bruno JF, Gaines SD, Halpern BS, Lester SE, Kinlan BP, Weiss JM (2007) Temperature control of larval dispersal and the implications for marine ecology, evolution, and conservation. Proceedings of the National Academy of Sciences, 104(4), 1266\u0026ndash;1271\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOnarheim IH, Smedsrud LH, Ingvaldsen RB, Nilsen F (2014) Loss of sea ice during winter north of Svalbard. Tellus A: Dynamic Meteorol Oceanogr 66(1):23933\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOverland J, Dunlea E, Box JE, Corell R, Forsius M, Kattsov V, Wang M (2019) The urgency of Arctic change. Polar Sci 21:6\u0026ndash;13\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePalerud R, Gulliksen B, Brattegard T, Sneli JA, Vader W (2004) The marine macro-organisms in Svalbard waters. A catalogue of the terrestrial and marine animals of Svalbard. Norsk Polarinstitutt Skrifter 201:5\u0026ndash;56\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaulsen ML, Dore H, Garczarek L, Seuthe L, Mueller O, Sandaa RA, Larsen A (2016) Synechococcus in the Atlantic gateway to the Arctic Ocean. Front Mar Sci 3:191\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePavlov AK, Tverberg V, Ivanov BV, Nilsen F, Falk-Petersen S, Granskog MA (2013) Warming of Atlantic Water in two west Spitsbergen fjords over the last century (1912\u0026ndash;2009). Polar Res 32(1):11206\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePiepenburg D (2005) Recent research on Arctic benthos: common notions need to be revised. Polar Biol 28(10):733\u0026ndash;755\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePromińska A, Falck E, Walczowski W (2018) Interannual variability in hydrography and water mass distribution in Hornsund, an Arctic fjord in Svalbard. Polar Res 37(1):1495546\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRantanen M, Karpechko AY, Lipponen A, Nordling K, Hyv\u0026auml;rinen O, Ruosteenoja K, Vihma T, Laaksonen A (2022) The Arctic has warmed nearly four times faster than the globe since 1979. Commun Earth Environ 3(1):1\u0026ndash;10\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRenaud PE, Berge J, Varpe \u0026Oslash;, L\u0026oslash;nne OJ, Nahrgang J, Ottesen C, Hallanger I (2012) Is the poleward expansion by Atlantic cod and haddock threatening native polar cod, Boreogadus saida? Polar Biol 35:401\u0026ndash;412\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRenaud PE, Riedel A, Michel C, Morata N, Gosselin M, Juul-Pedersen T, Chiuchiolo A (2007) Seasonal variation in benthic community oxygen demand: a response to an ice algal bloom in the Beaufort Sea, Canadian Arctic? J Mar Syst 67(1\u0026ndash;2):1\u0026ndash;12\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRenaud PE, Sejr MK, Bluhm BA, Sirenko B, Ellingsen IH (2015) The future of Arctic benthos: expansion, invasion, and biodiversity. Prog Oceanogr 139:244\u0026ndash;257\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRognstad RL, Hilbish TJ (2014) Temperature-induced variation in the survival of brooded embryos drives patterns of recruitment and abundance in Semibalanus balanoides. J Exp Mar Biol Ecol 461:357\u0026ndash;363\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRzhavsky AV, Kupriyanova EK, Sikorski AV, Dahle S (2014) Calcareous tubeworms (Polychaeta, Serpulidae) of the Arctic Ocean. KMK Scientific, Moscow, Russia, pp 1\u0026ndash;187\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSilberberger MJ, Renaud PE, Espinasse B, Reiss H (2016) Spatial and temporal structure of the meroplankton community in a sub-Arctic shelf system. Mar Ecol Prog Ser 555:79\u0026ndash;93\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSkogseth R, Olivier LL, Nilsen F, Falck E, Fraser N, Tverberg V, Falk-Petersen S (2020) Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation\u0026ndash;An indicator for climate change in the European Arctic. Prog Oceanogr 187:102394\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSouster T, Barnes DKA, Primicerio R, J\u0026oslash;rgensen LL (2024) Quantifying zoobenthic blue carbon storage across habitats within the Arctic\u0026rsquo;s Barents Sea. Front Mar Sci. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003eorg/10.3389/fmars.2023.1260884\u003c/span\u003e\u003cspan address=\"10.3389/fmars.2023.1260884\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSouster TA (2018) Marine Biodiversity of \u003cem\u003eAntarctic\u003c/em\u003e Hard Rock Communities: Species Biomass and Energy Use. \u003cem\u003ePhD thesis\u003c/em\u003e The Open University\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSowa A, Kuklinski P, Weydmann-Zwolicka A, Balazy P, Chelchowski M, S\u0026oslash;reide JE, Ronowicz M (2023) Factors shaping epibionts recruitment in the high Arctic (Isfjorden, Spitsbergen): A year-round investigation using experimental plates. Estuarine, Coastal and Shelf Science, 283, 108281\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStatSoft Inc (2007) STATISTICA (data analysis software system), version 8.0. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003c/span\u003e\u003cspan address=\"http://www.statsoft.com\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSt\u0026uuml;bner EI, S\u0026oslash;reide JE, Reigstad M, Marquardt M, Blachowiak-Samolyk K (2016) Year-round meroplankton dynamics in high-Arctic Svalbard. J Plankton Res 38(3):522\u0026ndash;536\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTemkin MH, Zimmer RL (2002) Phylum bryozoa. Atlas of marine invertebrate larvae, 411\u0026ndash;427\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTepes P, Gourmelen N, Nienow P, Tsamados M, Shepherd A, Weissgerber F (2021) Changes in elevation and mass of Arctic glaciers and ice caps, 2010\u0026ndash;2017. Remote Sens Environ 261:112481\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUshakova OO (2003) Combined effect of salinity and temperature on Spirorbis spirorbis L. and Circeus spirillum L. larvae from the White Sea. J Exp Mar Biol Ecol 296(1):23\u0026ndash;33\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVoronkov A, Hop H, Gulliksen B (2016) Zoobenthic communities on hard-bottom habitats in Kongsfjorden. Svalbard Polar Biology 39:2077\u0026ndash;2095\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalczyńska KS, S\u0026oslash;reide JE, Weydmann-Zwolicka A, Ronowicz M, Gabrielsen TM (2019) DNA barcoding of Cirripedia larvae reveals new knowledge on their biology in Arctic coastal ecosystems. Hydrobiologia 837:149\u0026ndash;159\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWassmann P, Duarte CM, Agusti S, Sejr MK (2011) Footprints of climate change in the Arctic marine ecosystem. Glob Change Biol 17(2):1235\u0026ndash;1249\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWatson DI, Barnes DKA (2004) Temporal and spatial components of variability in benthic recruitment, a 5-year temperate example. Mar Biol 145(1):201\u0026ndash;214\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeslawski JM, Wiktor J, Kotwicki L (2010) Increase in biodiversity in the arctic rocky littoral, Sorkappland, Svalbard, after 20 years of climate warming. Marine Biodivers 40:123\u0026ndash;130\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWethey DS, Woodin SA (2008) Ecological hindcasting of biogeographic responses to climate change in the European intertidal zone. In Challenges to Marine Ecosystems: Proceedings of the 41st European Marine Biology Symposium (pp. 139\u0026ndash;151). Springer Netherlands\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWisshak M, Meyer N, Kuklinski P, R\u0026uuml;ggeberg A, Freiwald A (2022) Ten Years After\u0026rsquo;\u0026mdash;a long-term settlement and bioerosion experiment in an Arctic rhodolith bed (Mosselbukta, Svalbard). Geobiology 20(1):112\u0026ndash;136\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"encrusters, benthic colonisation, subtidal, Arctic atlantification, artificial substrate, field experiment, Svalbard","lastPublishedDoi":"10.21203/rs.3.rs-4389944/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4389944/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAccelerated warming has been reported in the Arctic in recent years. Climate change forcing has been detected in many aspects of high-latitude ecosystem ecology. Given previous reports of shifts within the Arctic benthos, we anticipated changes when revisiting the structure of epibenthic assemblages colonising the shallow subtidal zone in Svalbard\u0026rsquo;s largest sill-less fjord, Isfjorden. To investigate that, experimental constructions holding replicate settlement plates (artificial substrata) were set up at two stations on the rocky bottom of southern Isfjorden in the summer of 2004 and were retrieved after a year of immersion. The same procedure was conducted again after 15 years, in summer 2019. The comparison of the samples from those two periods showed significant differences in assemblage structure. The most substantial change observed was a shift in species dominance suggesting a reorganisation of the assemblage. Most notable was a difference in the abundance of the typically Arctic bryozoan \u003cem\u003eHarmeria scutulata\u003c/em\u003e (from 100 to 0 ind. per 100 cm\u003csup\u003e2\u003c/sup\u003e between 2005 and 2020), which before 2004 was found to account for more than 50% of bryozoan individuals encrusting stones around Svalbard. The overall taxonomic composition was, however, representative of West Spitsbergen. The Arctic, particularly the Eurasia sector, has been under sustained climate change forcing long prior to the establishment of our field experiment, thus even the 2005 results may showcase an epibenthic assemblage in an already altered state. We think this emphasises how important robust baseline data are to provide crucial reference points to measure and understand change.\u003c/p\u003e","manuscriptTitle":"They always say time changes things – a comparative study of epibenthic assemblage in high Arctic fjord between 2005 and 2020","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-10 15:17:53","doi":"10.21203/rs.3.rs-4389944/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7040432e-110c-4238-8dc0-a5c370ca2963","owner":[],"postedDate":"July 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-08-02T15:38:11+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-10 15:17:53","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4389944","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4389944","identity":"rs-4389944","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}