Boat noise alters behaviour in a fish-shrimp mutualism.

Boat noise alters behaviour in a fish-shrimp mutualism. | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 23 June 2025 V1 Latest version Share on Boat noise alters behaviour in a fish-shrimp mutualism. Authors : Jack Manera 0009-0003-7947-6473 [email protected] , Jake Martin , Maria Palacios , Rachel Mason , Mark McCormick 0000-0001-9289-1645 , and Bob Wong Authors Info & Affiliations https://doi.org/10.22541/au.175068258.87978389/v1 273 views 171 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Persistent noise pollution produced by boat traffic is reshaping marine soundscapes globally. Despite growing ecological concern, most studies to date have focused on individual-level effects under laboratory conditions, leaving major gaps in our understanding of how boat noise shapes species interactions in the wild. Using field-based behavioural assays, we investigate how boat noise from different engine types (4-stroke and 2-stroke) affects the mutualistic partnership between Steinitz’s goby (Amblyeleotris steinitzi) and snapping shrimp (Alpheus spp.). Across 123 partnerships, we recorded behavioural responses before, during, and after noise exposure. Gobies increased burrow use during 4-stroke boat noise exposure, while shrimp responded stronger to 2-stroke noise—reflecting taxon-specific sensitivities to different noise spectra. Despite these shifts, tactile partner communication remained robust across treatments. These findings highlight divergent vulnerabilities between species tied to different engine acoustics, and emphasise the need for targeted research to inform strategies for mitigating marine noise pollution. Boat noise alters behaviour in a fish-shrimp mutualism. Jack L. Manera* 1 †, Jake M. Martin 1,2,3 †, Maria M. Palacios 4 , Rachel T Mason 2 , Mark I. McCormick 5 , Bob B.M. Wong 1 1 School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia 2 School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria 3216, Australia 3 Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden 4 Centre for Nature Positive Solutions, School of Science, RMIT University, Melbourne, Victoria 3000, Australia 5 Coastal Marine Field Station, School of Science, University of Waikato, Tauranga, New Zealand †These authors contributed equally as lead investigators *Corresponding author: Jack L. Manera, [email protected] Jack L. Manera: [email protected] , ORCID: 0009-0003-7947-6473 Jake M. Martin: [email protected] , ORCID: 0000-0001-9544-9094 Maria M. Palacios: [email protected] , ORCID: 0000-0002-5450-674 Rachel T Mason: [email protected] , ORCID: 0000-0003-2692-9902 Mark I. McCormick: [email protected] , ORCID: 0000-0001-9289-1645 Bob BM. Wong: [email protected] , ORCID: 0000-0001-9352-6500 Article type : Letter Short running title : Boat noise alters behaviour in a mutualism. Keywords : Noise pollution, ocean noise, animal behaviour, interspecies interaction, field study, Amblyeleotris steinitzi , Alpheus spp. Abstract word count : 150 Main text word count : 3850 Text box word count : Not applicable Number of references : 41 Number of figures : 4 Authors’ contributions: Following MeRIT guidelines, in the methods, we have reported what processes were conducted by the author team, to improve author contributions’ granularity and for reproducibility and replicability (see Methods). Here, we report a list of the author’s roles using the Contributor Role Taxonomy (CRediT). Jack L. Manera: Data curation (lead), Formal analysis (lead), Investigation (contributor), Methodology (contributor), Visualization (lead), Writing – Original Draft Preparation (co-lead), and Writing – Review & Editing (co-lead). Jake M. Martin: Data curation, Formal analysis, Supervision, Methodology, Writing – Original Draft Preparation (co-lead), and Writing – Review & Editing (co-lead). Maria M. Palacios: Conceptualisation, Investigation, Methodology, Writing – Review & Editing. Rachel T. Mason: Data curation, Writing – Review & Editing. Mark I. McCormick: Conceptualisation, Investigation, Methodology, Writing – Review & Editing. Bob BM. Wong: Conceptualisation, Investigation, Methodology, Funding Acquisition, Writing – Review & Editing. Data accessibility: All data and code (R script) used to produce this work are available on Jack L. Manera’s GitHub repository (https://github.com/JLManera/shrimp_goby_boatnoise). They are also available on the OSF framework (DOI: 10.17605/OSF.IO/3X5YF link: https://osf.io/3x5yf/?view_only=44476bf6fd63453194f065198908719a) Abstract Persistent noise pollution produced by boat traffic is reshaping marine soundscapes globally. Despite growing ecological concern, most studies to date have focused on individual-level effects under laboratory conditions, leaving major gaps in our understanding of how boat noise shapes species interactions in the wild. Using field-based behavioural assays, we investigate how boat noise from different engine types (4-stroke and 2-stroke) affects the mutualistic partnership between Steinitz’s goby ( Amblyeleotris steinitzi ) and snapping shrimp ( Alpheus spp. ). Across 123 partnerships, we recorded behavioural responses before, during, and after noise exposure. Gobies increased burrow use during 4-stroke boat noise exposure, while shrimp responded stronger to 2-stroke noise—reflecting taxon-specific sensitivities to different noise spectra. Despite these shifts, tactile partner communication remained robust across treatments. These findings highlight divergent vulnerabilities between species tied to different engine acoustics, and emphasise the need for targeted research to inform strategies for mitigating marine noise pollution. math_shortcuts 1. Introduction Human-generated noise is altering acoustic environments around the world. This issue is particularly pronounced in aquatic settings (Kunc et al. 2016), due to the distinct acoustic properties of water, where sound waves travel faster, further, and with greater intensity (Larsen & Radford 2018). Boat noise is one of the most prevalent forms of marine noise pollution (Hildebrand 2009). Large vessels travelling along global shipping lanes and smaller boats navigating coastlines and river systems produce a constant, and growing, source of noise pollution (Jalkanen et al. 2022; Wilson et al. 2022). Consequently, there are very few aquatic ecosystems that are not exposed to some form of boat noise (Duarte et al. 2021). The noise produced by boats typically falls within the 10–5000 Hz frequency range (Hildebrand 2009), which coincides with the hearing ranges of many aquatic wildlife, including fish (50–1500 Hz; Popper & Fay 2011) and invertebrates (e.g. snapping shrimp, 40–1500 Hz; Dinh & Radford 2021), making such taxa especially susceptible to boat noise pollution. The bulk of research to date, has focused on the effects of boat noise on individual species in laboratory settings, however, there is growing recognition of the need for ecologically relevant, field-based assessments. In confined environments, such as experimental aquaria, sound pressure and particle motion—the two fundamental components of sound waves—behave very differently compared to open bodies of water (Slabbekoorn 2016). This discrepancy makes field studies essential for replicating environmentally realistic sound conditions. Importantly, field assessments also provide the opportunity to examine how noise influences species within the broader context of the natural ecosystems they inhabit. Organisms do not exist in isolation; instead their survival and fitness are often shaped by ecological interactions, such as predation, parasitism, competition, and mutualism (Brown et al. 2001). These interactions can be disrupted (Nedelec et al. 2017a), or enhanced (Fernandez-Declerck et al. 2023), by noise pollution exposure, which has consequences for the stability and functioning of entire ecosystems (Francis et al. 2009). Thus, investigating the effects of boat noise on species interactions—rather than just on individual taxa—is crucial to gain a comprehensive understanding of the range of potential impacts of noise pollution. Accordingly, we set out to investigate the impacts of boat noise pollution on the behavioural interactions between two susceptible marine taxa: fish and crustaceans. To do so, we capitalised on the iconic and well-characterised mutualistic relationship between prawn gobies and burrowing shrimp, focusing specifically on Steinitz’s goby ( Amblyeleotris steinitzi ) and snapping shrimp ( Alpheus spp . ; Fig. 1). In these goby-shrimp mutualisms, which can involve more than one individual shrimp and/or goby, the shrimp excavate and maintain a shared burrow. In return, the goby serves as a sentinel, performing vigilance behaviours outside the burrow to detect, and communicate, potential threats to the shrimp. We hypothesised that boat noise exposure would disturb the mutualism of these two species by independently altering perceived risk, leading to shifts in behaviour, and potentially disrupting their communication. To test this, we used outboard engines on small dinghies representative of those typically operating over shallow reefs. Our study included both 4-stroke and 2-stroke engines, as these are the most widely used in vessels and have previously been shown to impact fish and invertebrates (McCormick et al. 2018; Nedelec et al. 2014, 2017b). Although the acoustic spectra of both engines are broadly similar, 2-stroke motors exhibit a lower acoustic complexity and generally higher intensity, across most key metrics (e.g. higher root-mean-square levels, higher peak energy, larger 90% energy envelope, and higher consistency; McCormick et al. 2018, 2019). Consequently, we predicted that noise from 2-stroke engines would have a greater impact on the behaviour of gobies and shrimp ( sensu Jain-Schlaepfer et al. 2018; McCormick et al. 2018). 2. Material and methods Methods are reported following ‘Method Reporting with Initials for Transparency’ (MeRIT), to further clarify contributor roles for reproducibility and replicability (Nakagawa et al. 2023). (a) Study site This study was performed between 25 October and 25 November 2017 at Lizard Island (14°41’9”S, 145°27’21”E) on the Great Barrier Reef, Australia. Within the lagoon, five different sites were identified as sampling locations (see Fig. 2). This lagoon was selected as it represents a section of the Great Barrier Reef lagoonal basin with relatively low vessel traffic (McCormick et al. 2018). Each site had a large population of Steinitz’s gobies with burrows located on soft sediments at 2–3 m water depth and 1–2 m from the reef edge. The experimental design was conceived by MMP, BBMW and MIM. (b) Boat noise treatments The vessels used for noise pollution treatments were 5 m long aluminium hull dinghies, with either a 30 horsepower 4-stroke outboard motor (Suzuki DF30A) or a 30 horsepower 2-stroke outboard motor (Suzuki DT30; n = 3 boats per engine type), with identical hull design. Both 4-stroke and 2-stroke motorboats were used as distinct treatments in this study because of the different sound characteristics of the two motors, and the potential for different effects on wildlife (Jain-Schlaepfer et al. 2018; McCormick et al. 2018, 2019). The 4-stroke and 2-stroke boats deployed in the current study are identical to those used in previously published research where measurements were made at similar locations on the same reef under approximately the same weather conditions; as a result, their acoustic properties have already been characterised and reported elsewhere (McCormick et al. 2018, 2019). In addition to the two different boat noise treatments, there was also a control treatment, in which no boat was driven near the site and consisted of only naturally occurring ambient ocean noise (methods adapted from Harding et al. 2020). Each of the goby-shrimp burrows was allocated randomly to one of the three treatments, ensuring similar representation across all five sites (control, 4-stroke, or 2-stroke: n = 51, 40, and 51, respectively; see Table S1 for site-specific breakdown). The boat noise was implemented following protocols of Harding et al. (2020), with the 4-stroke or 2-stroke boat being driven using varying steering patterns for 10 min, 10–200 m from the focal burrow. (c) Field experiments Trials involved filming burrows of Steinitz’s goby and snapping shrimp before, during and after being exposed to one of the three noise treatments. Burrows were selected by first locating a large burrow opening, then confirming the presence of A. steinitzi (>10 cm SL) before proceeding. Once a suitable goby–shrimp pair had been identified, MMP positioned a video camera (GoPro Hero 5, GoPro Inc.) approximately 2 m from the burrow entrance and started the video recording before snorkelling away from the site. The experimental trial had four parts: a 20 min acclimation period when no behaviour was measured, and then three distinct 10 min phases (Fig. 2). The first 10 min was the ‘pre’ treatment phase, which was used to acquire a measure of baseline behaviour and activity from the focal goby and shrimp. This was followed by a 10 min ‘during’ treatment phase, when the noise treatments were administered (i.e. control, 4-stroke, or 2-stroke). The final 10 min was the ‘post’ treatment phase and was used to test potential carry-over effects after the noise exposure had ceased. Over the four weeks of the study, trials were conducted using a randomised combination of sites, noise treatments, and specific boats to minimise potential confounding effects from these factors. To avoid resampling the same gobies, each burrow’s location was mapped. All trials were conducted between 14:00 and 17:00 hrs ( N = 142). (d) Behavioural measurements For all response variables, only the middle 5 min (e.g. between 2.5–7.5 min) for each of the three experimental phases (pre-, during-, and post-) were extracted for data analysis (Fig. 2). This was done to avoid any potential overlap of sound conditions at the junction of the different phases. The 5 min recordings were labelled with a code, their order randomised, and their audio removed (by RTM), so that the data extraction process, carried out by JLM, was blinded to treatment and phase. All behavioural measurements were manually scored, with the keylogging behavioural analysis software BORIS v. 7.10.2 (Friard & Gamba 2016). The ethogram used to score behaviour was designed by JMM and JLM, with input from all co-authors. To investigate the effects of boat noise pollution on risk perception, the total time gobies and shrimp spent refuging was recorded. The time spent refuging was defined as the total time spent partly or entirely inside the burrow (i.e., having any body part inside the burrow was considered refuging). Refuging is a common antipredator behaviour frequently used as a proxy of risk perception (Bonenfant & Kramer 1996; Polverino et al. 2024; Wong et al. 2005). Therefore, when there is a high perceived risk, individuals are expected to spend more time refuging (Lima & Dill 1990). To assess if boat noise affects the communication between the mutualistic partners, the total time an individual spent in contact with a heterospecific partner was recorded. The goby communicates potential threats to the shrimp primarily through tactile signals (Kingston et al. 2019; Preston 1978), such as fin flicks, which the shrimp detects via their elongated antennae (Karplus 1979). However, as antennal contact was often not possible to ascertain from the recordings, we adopted a conservative proxy for contact. Specifically, focal animals were deemed to be in contact with one another when the most anterior point of the shrimp’s rostrum was within 1 body length of the goby or when both individuals were inside the burrow together (antennae are approximately 1.5× the body length of a shrimp; Karplus & Thompson 2012). All behavioural measurements were scored for the three phases (pre-, during and post-treatment, see Fig. 2). (e) Statistical analysis Data were analysed in RStudio (v. 2023.09.1, Posit Software, PBC) and R (v. 4.3.2, 2023, the R Foundation for Statistical Computing) by JLM, with input from JMM. From the original 142 burrows that were sampled, 19 did not contain at least one shrimp and one goby. These burrows were removed from analysis, leaving a total of 123 burrows (control: n = 39; 4-stroke: n = 37; 2-stroke: n = 47). Some burrows contained multiple gobies and/or shrimp, which prevented our ability to preserve individual identity. Consequently, behaviours were recorded for all individuals of each species (goby or shrimp), and the scores were averaged by the number of individuals from that species in each trial. The time that gobies and shrimp spent refuging and in contact with one another was recorded as a proportion of the total trial time. Refuging behaviour and contact were modelled using Bayesian generalised linear mixed-effects models with zero-one inflated beta distributions ( brms package; Bürkner 2017). Traditional beta distributions cannot handle boundary values of 0 and 1; therefore, the zero-one inflated beta distribution was chosen to handle cases where the goby or shrimp spent the entire observation period either outside/inside the burrow or in contact/apart from one another, resulting in exact values of 0 or 1. The predictor variables included the noise treatment (control, 4-stroke, or 2-stroke), the phase of the experiment (pre-, during-, or post-noise exposure), and the interaction between noise treatment and phase. Covariates included the species of the shrimp, the number of shrimps, and the number of gobies in each burrow. Burrow ID, nested within sample site, was included as a random intercept to account for the repeated measures design (i.e., each burrow was measured at the three distinct phases). The models included shrimp species to account for the fact that various species of snapping shrimp ( Alpheus spp . ) form these mutualisms within the Lizard Island lagoon, and that they may be differentially sensitive to noise pollution. Each model was run across four chains using broadly non-informative priors for 4000 iterations with 1000 warm-ups. The convergence of the models was ascertained through adequate mixing observed in the trace plots (evidenced by R-hat values being 1). To incorporate all the coefficients associated with both the zero-one inflation process and the beta distribution within our model, the emmeans package (version 1.10.7; Lenth 2025) was used. This facilitated the calculation of the estimated marginal mean posterior distributions for each level of the fixed effects and their interactions. Furthermore, emmeans was used to compute pairwise contrasts between experimental phases (pre, during, post) for each noise treatment. The model predictions are presented as estimated marginal means accompanied by 95% credible intervals (CrI), with inference based on contrast estimates where CrIs do not overlap with zero. 3. Results (a) Goby behaviour For control gobies, the proportion of time spent out of their burrows did not differ across the pre-, during-, and post-exposure phases of the experiment (all estimated marginal contrasts overlap with zero; Fig. 3a, Tables S2 and S3). Similarly, for gobies exposed to 2-stroke boat noise, there was no discernible change in the time spent outside their burrows across the three phases (Fig. 3a, Tables S2 and S3). However, for gobies subjected to the 4-stroke boat noise, there was a 22% reduction in the time they spent out of their burrows (Fig. 3a, Tables S2 and S3). Prior to noise exposure the average proportion of time gobies spent outside of their burrows was 0.69 [0.51, 0.85, lower and upper 95% CrI respectively], but during the 4-stroke boat noise this decreased to 0.53 [0.35, 0.72], a mean reduction of 0.15 [0.01, 0.29]. Once the noise ceased in the post-exposure phase, goby burrow use returned to near pre-exposure levels (0.60 [0.41, 0.78]; Fig. 3a, Tables S2 and S3). The number of gobies in the burrow had a marginal influence on the proportion of time gobies spent out of the burrow. Specifically, if only one goby was present ( n = 28 cases), the average proportion of time that goby was out of the burrow was 0.58 [0.42, 0.73], whereas when two gobies were present ( n = 95 cases), the average proportion of time each goby was out of the burrow was 0.71 [0.55, 0.84], a difference of 0.13 [0.00, 0.25] (however this difference was marginal, as the CrI’s include 0; Table S3). Similarly, the number of shrimps in the burrow influenced the proportion of time that gobies spent out of the burrow. Specifically, when only one shrimp was present ( n = 25 cases), the average proportion of time gobies spent out of the burrow was 0.57 [0.41, 0.71], whereas when two shrimps were present ( n = 95 cases), this increased to 0.71 [0.61, 0.80], a difference of 0.14 [0.03, 0.27] (Table S3). In rare cases ( n = 3), there were three shrimp in the burrow. However, because of the low occurrence, we have low confidence in these estimates. Moreover, contrasts comparing three shrimp to one or two shrimp revealed no meaningful differences (differences of 0.09 [ -0.22, 0.36] and -0.06 [ -0.37, 0.19] respectively). Lastly, the species of shrimp in the burrow did not affect the proportion of time gobies spent out of the burrow (Table S3). (b) Shrimp behaviour For both the control shrimp and those exposed to 4-stroke boat noise, the proportion of time spent out of their burrows did not differ across the pre-, during-, and post-exposure phases of the experiment (Fig. 3b, Tables S2 and S4). Conversely, shrimp exposed to the 2-stroke boat noise exhibited a noticeable reduction in the proportion of time spent out of the burrow (Fig. 3b, Tables S2 and S4). Specifically, before exposure to the 2-stroke noise, shrimp spent on average 0.32 [0.19, 0.45] and during noise exposure they spent on average 0.21 [0.12, 0.31], a difference of 0.11 [0.03, 0.20], a 34% decrease in the amount of time they spent out of their burrow. This change in the proportion of time spent out of the burrow returned towards baseline in the post exposure phase (0.24 [0.14, 0.36]), however, it should be noted that our effect estimates partially support a difference between the pre- and post-noise phases as the credible intervals overlapped marginally with zero (0.08 [-0.00, 0.17]; Fig. 3b, Tables S2 and S4). The number of gobies and the species of shrimp did not affect the proportion of time the shrimp spent outside of their burrow (Table S4). The number of shrimp present did affect their time out of the burrow, with the average proportion of time spent out of their burrow increasing by 0.12 [0.02, 0.20] when two shrimp were present ( n = 95 cases), compared to when one shrimp was present ( n = 25 cases; Table S4). Again, in the few cases where three shrimp were present ( n = 3), no change in burrow use was observed—likely due to the high uncertainty associated with such a low occurrence. Burrow use did not differ between the different species of shrimps (Table S4). (c) Shrimp-goby communication The proportion of time shrimp maintained physical contact with a goby was unaffected by the different noise treatments (control, 4-stroke, and 2-stroke; Fig. 4, Tables S2 and S5), number of gobies, number of shrimp, and the species of shrimp (see Table S5). Overall, shrimp spent on average 0.67 [0.54, 0.79] of their time in contact with a goby. math_shortcuts 4. Discussion Our results reveal that boat noise pollution can significantly alter the behaviour of shrimps and gobies in a mutualistic partnership. Exposure to boat noise increased the tendency for both gobies and shrimp to seek refuge—a response that indicates an elevated perception of risk. Importantly, the data show that 2-stroke and 4-stroke boat noise elicit distinct behavioural responses. Shrimp displayed a pronounced reaction to 2-stroke engine noise, whereas gobies responded to 4-stroke engine noise. Despite these shifts in individual behaviours, the tactile communication for their mutualism was unaffected by noise exposure. The overall increase in refuging behaviour supports the hypothesis that both gobies and shrimp perceived the boat noise as an increased risk. This aligns broadly with work on other refuge-seeking species’ (Jennions et al. 2003), including other species of gobies (Polverino et al. 2024), which show that animals adjust their burrow use to match perceived threat levels. The increase in perceived risk could arise from the gobies interpreting the noise itself as a direct threat or from the noise interfering with their ability to detect other threats, potentially via acoustic masking or cognitive impairment (Chan et al. 2010). Similar increases in refuging behaviour in response to boat noise have been observed in other species, such as red-mouthed gobies ( Gobius cruentatus ; Picciulin et al. 2010) and Ward’s damselfish ( Pomacentrus wardi ; McCormick et al. 2018). These changes in burrow use can be costly, as although seeking refuge can reduce predation risk, it also limits the opportunities for feeding, mating, and defending territories (Frid & Dill 2002). Such trade-offs can have significant fitness consequences; for instance, male Lusitanian toadfish ( Halobatrachus didactylus ) exposed to boat noise spent more time performing antipredator behaviours and less time courting potential mates, ultimately leading to reduced reproductive success (Amorim et al. 2022). Our results reveal species-specific responses to the different engine types, each of which has distinct acoustic signatures. Gobies only exhibited a behavioural response to 4-stroke noise, which is characterised by a more complex sound (Jain-Schlaepfer et al. 2018; McCormick et al. 2018). In contrast, shrimp were affected by 2-stroke engine noise, which is associated with a higher overall intensity (McCormick et al. 2018). The differences in taxon responses may be partly explained by variation in auditory structures: snapping shrimp primarily detect sound using statocysts (Dinh & Radford 2021), whereas gobies predominantly use saccules (Vetter 2025). Although both organs are tuned to low frequencies—specifically the particle acceleration component of sound—studies in closely related species indicate that snapping shrimp have peak sensitivities around 80–100 Hz ( Alpheus richardsoni ; Dinh & Radford 2021) and gobies around 100–300 Hz ( Pomatoschistus pictus and P. marmoratus ; Amorim et al. 2018). Acoustic measurements by McCormick et al . (2018) show that 2-stroke engines emit disproportionately high particle acceleration noise at lower frequencies, which aligns more with shrimp hearing sensitivity and may explain their stronger response to 2-stroke noise. With that said, this frequency-based explanation does not account for the gobies’ reaction to 4-stroke noise, which is relatively lower-intensity across their hearing range (~100–300 Hz). This suggests that factors beyond frequency sensitivity—such as differences in the processing of acoustic signals—may underlie these species-specific responses. Similar patterns have been observed in other species: for example, 2-stroke engines were shown to elicit more pronounced stress responses in staghorn damselfish ( Amblyglyphidodon curacao ; Jain-Schlaepfer et al. 2018), whereas 4-stroke noise triggered stronger startle responses in juvenile whitetail damselfish ( Pomacentrus chrysurus ; McCormick et al. 2019). These species-specific sensitivities highlight the complexity of how different engine noises are processed and perceived and are reflective of broad taxa-level differences in responses to noise pollution (Kunc et al. 2016). Incorporating auditory-evoked potential measurements (changes in brain activity produced by auditory stimuli) could offer a more mechanistic insights into how these sounds are being perceived by the different species and not just their relative intensities. Regardless of the mechanism, species-specific sensitivity to the different noise spectra may represent a wider challenge for management strategies aimed at reducing the impacts of aquatic noise pollution. Thus, selectively reducing a given engine type may not alleviate risks for all species and could, in fact, exacerbate impacts for some. Importantly, our results do not indicate substantial carry-over effects on behaviour, as the increased refuge use observed during noise exposure returned towards baseline once the noise ceased. This aligns with findings from other studies where behavioural alterations induced by noise exposure were short-lived (Bruintjes et al. 2016). However, carry-over effects have been documented in other species, such as increased aggression in orange-fin anemonefish ( Amphiprion chrysopterus ; Mills et al. 2020) and reduced cleaning efficiency in bluestreak cleaner wrasse ( Labroides dimidiatus ; Nedelec et al. 2017a). Taken together, our results and those of previous studies underscore the importance of species-specific investigations to fully understand the long-term impacts of noise pollution on marine ecosystems. Despite the shifts in individual refuge use, boat noise exposure did not impact the tactile communication between shrimp and gobies, suggesting that this aspect of their mutualism is relatively resistant to noise disturbances. Tactile signals are crucial for their cooperative interactions (Karplus & Thompson 2012), and their persistence despite noise exposure highlights the resilience of this communication system (Burns et al. 2019). In conclusion, this study provides important evidence that boat noise pollution significantly alters the behaviour of animals engaged in mutualistic partnerships. While the interspecies interaction between gobies and shrimp remained intact, their refuging behaviour was affected by noise exposure. Notably, species exhibited differential sensitivity to 2-stroke and 4-stroke engine noise, highlighting the complexity of noise pollution effects. These findings emphasize the importance of field-based research in understanding the real-world impacts of anthropogenic noise on marine species and underscore the need for targeted conservation efforts to mitigate the increasing threat of noise pollution. Ethics All work carried out herein was in accordance with the James Cook University Animal Ethics guidelines (JCU Animal Ethics approval A2081 and A2361). Declaration of AI use We have not used AI-assisted technologies in creating this article. Competing interests We declare we have no competing interests. Funding This work was supported by an ARC Discovery (MIM; DP170103372) and an Alfred Deakin Postdoctoral Research Fellowship (JMM). Acknowledgements We want to thank Dr Chris Hemingson and Dr Alyssa Giffin for supporting MMP during the filming and data collection campaign. We are especially grateful to Dr Tim Lamont (T Gordon) and Dr Sophie Nedelec for their invaluable acoustic guidance in the field, which was essential for implementing noise treatments and identifying relevant exposure stages. We also want to acknowledge the directors and staff at Lizard Island Research Station (LIRS), who facilitated all the on-ground logistics to make this work possible. References Amorim, M.C.P., Vasconcelos, R.O., Bolgan, M., Pedroso, S.S. & Fonseca, P.J. (2018). Acoustic communication in marine shallow waters: testing the acoustic adaptive hypothesis in sand gobies. J. Exp. Biol. , 221, jeb183681. 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(A) The distinct phases of each trial, including a 20 min acclimation period, followed by 10 min pre-, during-, and post-noise treatment phases, with a 5 min observation window for behavioural recordings in the middle of each phase. (B) A map of the sample site locations within the Lizard Island lagoon, Great Barrier Reef, Australia (14°41’9”S, 145°27’21”E; see Table S1 for site-specific sample sizes). (C) The behavioural measurements including refuge use and tactile communication, which was assessed by the physical proximity of a shrimp to a goby. Figure 3. The proportion of time gobies spent outside their burrow (A) and shrimp spent outside their burrow (B), before (Pre), during, and after (Post) exposure to different noise treatments: control ( n = 39), 4-stroke boat noise ( n = 37), and 2-stroke boat noise ( n = 47). The left side of each treatment by exposure phase, displays the raw data, with scatter plots and a horizontal line indicating the raw data mean. The right side displays model estimates, with the diamonds representing the model-estimated marginal mean, error bars the 95% credible intervals, and density plots the posterior distribution. For the marginal differences of pairwise comparisons see Table S3 and S4. Figure 4. The proportion of time that gobies and shrimp were in contact before (Pre), during, and after (Post) exposure to different noise treatments: control ( n = 39), 4-stroke boat noise ( n = 37), and 2-stroke boat noise ( n = 47). The left side of each treatment by exposure phase, displays the raw data, with scatter plots and a horizontal line indicating the mean. The right side displays model estimates, with the diamonds representing the model-estimated marginal mean, error bars the 95% credible intervals, and density plots the posterior distribution. For the marginal differences of pairwise comparisons Table S5. Information & Authors Information Version history V1 Version 1 23 June 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords alpheus amblyeleotris steinitzi animal behaviour field study interspecies interaction noise pollution ocean noise Authors Affiliations Jack Manera 0009-0003-7947-6473 [email protected] Monash University - Clayton Campus View all articles by this author Jake Martin Deakin University View all articles by this author Maria Palacios RMIT University View all articles by this author Rachel Mason Deakin University View all articles by this author Mark McCormick 0000-0001-9289-1645 James Cook University Faculty of Science and Engineering View all articles by this author Bob Wong Monash University View all articles by this author Metrics & Citations Metrics Article Usage 273 views 171 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Jack Manera, Jake Martin, Maria Palacios, et al. 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