From Paper Parks to Real Protection: Ecological Performance of No-Take Zones in Aceh Besar, Indonesia

From Paper Parks to Real Protection: Ecological Performance of No-Take Zones in Aceh Besar, Indonesia | 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 From Paper Parks to Real Protection: Ecological Performance of No-Take Zones in Aceh Besar, Indonesia Rian Firdaus, Fredinan Yulianda, Zairion Zairion, Gatot Yulianto, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8589881/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 This study aimed to quantify the ecological responses of coral reef habitats and fish communities within four adjacent no-take zone (NTZs): Lhoknga, Lampuuk, Bunta Island, and South Batee Island in Aceh Besar Marine Protected Area, Indonesia, and to test whether protection implemented between 2018 and 2024 has improved ecosystem condition. Using a before-and-after comparative design, benthic cover and reef fish community structure were quantified from field surveys. Field survey data were integrated with satellite-derived water quality parameters, including sea surface temperature and nutrients. Results revealed spatial heterogeneity in recovery trajectories, with no statistically significant aggregate changes in live coral cover, fish abundance, or fish biomass across the NTZ network. South Batee Island exhibited exceptional benthic recovery but a substantial decline in fish biomass, indicating a critical disconnect between habitat improvement and resource protection, driven by weak enforcement. In contrast, only Bunta Island maintained concurrent positive trends in both habitat conditions and fish biomass. Across all sites, rising sea surface temperatures imposed chronic thermal stress. These findings challenge the assumption that regulatory designation of no-take zones guarantees ecosystem restoration in Aceh Besar, revealing instead that enforcement intensity, habitat quality, and climate stress determine NTZ effectiveness to a far greater extent than legal status alone, underscoring the urgent need to shift management focus from nominal protection to active compliance monitoring and adaptive management. Marine protected areas no-take zones ecological performance before–and–after monitoring Aceh Besar Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Introduction Marine ecosystems and their associated biota have been negatively impacted by climate change (Venegas et al. 2023), which is further exacerbated by increasing anthropogenic pressures (Zhao et al. 2025). To protect marine ecosystems, the International Union for Conservation of Nature has developed the concept of Marine Protected Areas (Grorud-Colvert et al. 2021). MPAs are established to conserve biodiversity, maintain ecosystem functions, and ensure sustainable resource utilization through an ecosystem-based approach to marine area management. MPA planning and management is often comprised of zoning systems, ranging from single-use to multi-use designations (Horta e Costa et al. 2016). In the MPA framework, no-take zones (NTZs) are specific types of marine protected areas where all extractive activities are strictly prohibited (Costello and Ballantine 2015). NTZs in a marine reserve provide the best protection for ocean ecosystems (Sala and Giakoumi 2018) and are supported by recent findings (Hopf et al. 2024). No-take zones have proven more effective at increasing fish abundance and biomass compared to open waters, with evidence derived from various long-term and short-term studies. Early research demonstrated that no-take zones can increase species populations (Alcala 1988) and accelerate the recovery of depleted fish stocks. Subsequent findings revealed that no-take zones not only strengthen fish stocks within the zone (Halpern 2003) But also promote the spillover of adult fish and larvae to surrounding areas (Gell and Roberts 2003; Russ et al. 2004). No-take zones generally exhibit higher biomass compared to open waters (Lester 2009), with target species abundance consistently higher within no-take zones due to the absence of fishing pressure (Halpern et al. 2009). Recent research indicates that no-take zones are effective in restoring biomass and recovering ecosystem ecological functions. Biomass increases of 463% were observed in Cabo Pulmo National Park over approximately 10 years (Aburto-Oropeza et al. 2011). NTZs in Tapanuli Tengah (North Sumatra) achieve significantly higher coral cover (64–69%) and fish abundance (10,520–19,440 ind. ha⁻¹) compared to non-protected areas (Harahap et al. 2025). Despite their demonstrated effectiveness across multiple contexts, although no-take zones are recognized as effective, their success often varies across locations due to influences from zone size (Claudet 2008; Espinosa-Andrade, 2020; Ohayon et al. 2021), habitat conditions (Rees et al. 2018; Baliwe et al. 2022), enforcement level (Campbell et al. 2012; Advani et al. 2015) and community engagement (Kura et al. 2023). This study focuses on Aceh Besar Regency, which faces the Indian Ocean directly, and is one of Indonesia's marine protected area implementing a multi-use zoning system based on resource utilization (Muhammad et al. 2021). This zoning system comprises: (1) No-take zones, (2) Sustainable Fisheries Zones, (3) Utilization Zones, and (4) Other Zones. The area is utilized by approximately 4,577 fishers, the majority of whom are classified as small-scale fishers according to Indonesian definitions (Halim et al. 2019). However, despite the implementation of this conservation framework, significant knowledge gaps persist regarding the ecological outcome in Aceh Besar Regency. Specific evaluations regarding the effectiveness of no-take zones remain unavailable in the literature or in management reports. Scientific data concerning the ecosystems and resources within the NTZs, particularly those implemented between 2018 (proposed by the local Government) and 2020 (established by the central Government), remains unavailable to date. Although the Indonesian Government has established formal monitoring frameworks for MPA effectiveness, namely the Technical Guidelines for Evaluating the Management Effectiveness of Aquatic, Coastal, and Small Islands Conservation Areas (E-KKP3K), subsequently renamed as the Evaluation of the Effectiveness of Conservation Area Management (EVIKA), these frameworks have not been rigorously implemented in practice. This information gap hinders monitoring and evaluation efforts, thereby limiting understanding of the extent to which existing conservation strategies have been successful or unsuccessful. To address these critical research gaps and provide empirical evidence for this understudied system, this study aims to evaluate the response of coral reef ecosystems and fish resources in no-take zones between 2018 and 2024 using a before–and–after approach. This research contributes to understanding ecological performance in adjacent NTZs, providing empirical evidence essential for evaluating conservation efficacy in tropical systems. This investigation addresses whether the implementation of no-take zones during this period successfully enhanced ecosystem conditions and fish resources, thereby informing future management and policy decisions for marine conservation in Indonesia and beyond. Methods A before–and–after comparative framework was applied to quantify ecological changes in four NTZs in Aceh Besar, Indonesia: Lhoknga, Lampuuk, Bunta Island, and South Batee Island. Baseline field surveys conducted in 2018 were compared with resurveys in 2024. The NTZ at Tuan Island was excluded from temporal analysis due to its relocation to Lhok Keutapang in 2024. Benthic composition was quantified using photographic transects (50 m) and processed using Coral Point Count with Excel extensions (CPCe) (Kohler and Gill 2006). Each image was annotated with a 25-point uniform grid, producing approximately 1,875 points per site. Benthic categories included live coral, dead coral, dead coral with algae, rubble, soft coral, sponge, sand, rock, and other substrates . Reef fish communities were assessed using Underwater Visual Census (UVC)(English et al. 1998) along two replicated belt transects per site, each spanning 100 × 5 m (Samoilys and Carlos 2000). Fish biomass (kg ha⁻¹) was estimated from total length measurements using species-specific length-weight relationships \(\:W={a\:L}^{b}\) with parameters obtained from FishBase (Ernawati et al. 2024). To contextualize ecological responses within the broader oceanographic environment, water quality parameters were derived including sea surface temperature (°C), salinity (practical salinity units, psu), pH, dissolved oxygen (mmol m⁻³), nitrate (NO₃⁻), and phosphate (PO₄³⁻) from Marine Copernicus datasets (CMEMS GLO12) spanning 2018–2024. This incorporation captured spatial and temporal variability in water quality parameters across NTZs. Temporal differences between 2018 and 2024 were examined using paired t-tests and Mann-Whitney U tests, depending on the data characteristics, with effect sizes reported as Cohen's d. Fish community composition was evaluated using PERMANOVA (Bray-Curtis dissimilarity; 9,999 permutations), followed by Similarity Percentage (SIMPER) analysis to identify the contributing factors to temporal dissimilarity. Relationships among water quality variables were assessed using the Pearson correlation coefficient. All statistical analyses were performed in PAST v4.17 (Hammer et al. 2001) with significance determined at α = 0.05. The spatial configuration of the Marine Protected Area network, illustrating the proximity of sampling stations to diverse management zones, is presented in Fig. 1 . Specific operational details, including the exact coordinates and dimensions of the designated no-take zones, are summarized in Table 1 . Table 1 Study Sites within No-Take Zone Marine Protected Areas No-take zone Size (ha) Lat-Long Date Survey After Before Lhoknga 17.04 95.21694° E, 5.43385° S 2024/07/12 2018/02/03 Lampuuk 90.00 95.21677° E, 5.48455° S 2024/07/12 2018/02/03 Bunta Island 105.60 95.15025° E, 5.55320° S 2024/07/12 2018/02/03 South Batee Island 124.52 95.33340° E, 5.95338° S 2024/11/30 2018/02/20 Lhok Keutapang 66.60 95.20022° E, 5.55232° S 2024/11/30 NA Tuan Island NA 95.24817° E, 5.56403° S NA 2018/02/20 Results Benthic and Geomorphic Characteristics in the No-take zone Satellite imagery from the Allen Coral Atlas provided baseline data on benthic cover within the designated NTZs. These data revealed that each NTZ exhibited distinct ecological characteristics from the outset of its designation. Although relatively small in size, the NTZ in Lhoknga displayed the highest benthic cover percentage. In contrast, the larger NTZ in South Batee Island showed lower benthic cover. These differences are likely attributed to geomorphological factors, such as the dominance of reef slopes and inner reef flats in Lhoknga and Lampuuk, compared to the prevalence of terrestrial reef flats and shallow lagoons in South Batee Island and Lhok Keutapang. Geomorphological analysis of five study sites revealed spatial heterogeneity in reef structure, with reef slope as the dominant (Lampuuk: 99.45%; Lhoknga: 73.04%; Bunta Island: 53.72%; South Batee Island: 49.53%) and terrestrial reef flat in one location (Lhok Keutapang: 46.23%). These initial observations reflect the pre-existing condition of coral reef habitats before the full implementation of protection measures. They should not be interpreted as the direct outcome of conservation efforts. A detailed quantitative breakdown of the initial benthic composition and geomorphic zones for each site is provided in Table 2. Table 2. Benthic composition and Geomorphic zonation within no-take zones (NTZs). Substrate component Unit Lhoknga Lampuuk Bunta Island South Batee Island Lhok Keutapang NTZ size ha 17.04 90 105.6 124.52 66.6 Benthic cover Coral/Algae ha 6.68 27.43 22.02 19.59 10.4 Rock ha 0.51 0.47 2.84 1.22 0.81 Rubble ha 2.94 0.59 4.16 11.89 4.84 Sand ha 0.07 NA 1.33 2.54 0.55 Seagrass ha 0.65 0.15 2.08 0.76 2.68 Total benthic area ha 10.85 28.64 32.43 36 19.28 % of NTZ area % 63.67 31.82 30.71 28.91 28.95 Geomorphic zone Reef Slope ha 8.95 17.94 32.17 16.94 8.61 Terrestrial Reef Flat ha 2.93 0.07 20.4 11.57 9.01 Inner Reef Flat ha 0.18 NA 2.87 2.58 0.01 Outer Reef Flat ha 0.19 NA 0.22 0.48 0.53 Back Reef Slope ha NA NA 2.01 1.05 0.05 Shallow Lagoon ha NA NA 1.64 NA NA Deep Lagoon ha NA 0.02 0.57 1.09 NA Plateau ha NA 0.01 NA 0.5 1.27 Total geomorphic area ha 12.25 18.04 59.88 34.21 19.48 % of NTZ area % 71.89 20.04 56.7 27.47 29.25 The data reveal fundamental structural differences between sites, with Lhoknga dominated by reef slopes while South Batee Island features extensive terrestrial reef flats. To visualize this spatial heterogeneity, Figure 2 maps the distribution of benthic habitats and geomorphic features across the five study sites. Coral Cover Change Benthic community composition analysis identified distinct ecological response patterns. Bunta Island and South Batee Island demonstrated the highest recovery capacity, sustaining high and stable live coral cover (>60%) throughout the 6-year study period. South Batee Island exhibited an exceptional reversal in ecological performance. In 2018, severe reef degradation, characterized by the dominance of dead coral, was apparent. By 2024, recovery was evident through a decrease in dead coral cover, accompanied by an increase in live coral cover. This rapid reversal indicates high recovery potential and suggests adequate larval supply. Both no-take zones demonstrated high ecological resilience, characterized by fast recovery rates. The temporal dynamics of benthic substrate composition, contrasting the shifts between live and dead coral cover over the six years, are illustrated in Figure 3. Lampuuk NTZ demonstrated positive but gradual recovery. This recovery rate was attributed to persistent environmental stress, particularly sedimentation pressure. Sedimentation at this site originated from natural terrestrial runoff during the rainy season and local hydrographic and oceanographic dynamics that accumulated sediment. Lampuuk exemplified a location with a positive but constrained recovery trajectory. Lhoknga NTZ also demonstrated positive recovery patterns. However, rubble persistence remained high despite increasing coral cover. Observations indicate this site remains in an early recovery phase with incomplete substrate restabilization. Lhok Keutapang NTZ, with limited 2024 data, displayed moderate reef status characterized by balanced composition between live coral and consolidated substrates (rock). However, the presence of rubble indicates physical stress or degradation events. Stable, hard substrate availability (such as rock) offers potential for prospective coral expansion, provided physical stability is maintained. Statistical analysis of live coral cover across four no-take zones (Lhoknga, Lampuuk, Bunta Island, and South Batee Island) revealed no significant temporal changes. Although mean cover increased from 41.8% to 49.1%, paired t-tests demonstrated this increase was not statistically significant (p = 0.56; Cohen's d = 0.43). Substantial spatial variability characterized the study sites. Lhoknga and Lampuuk experienced live coral cover declines of 14.7% each, while South Batee Island exhibited the highest increase at 77.7%. Dead coral cover similarly showed no significant temporal change (p = 0.78; Cohen's d = 0.2), despite pronounced site-level differences. Lhoknga increased 34.5% while South Batee Island decreased 38.5%. This spatial heterogeneity in recovery trajectory highlights the importance of understanding site-specific reef resilience mechanisms and the effectiveness of science-based marine management. Recovery trajectories revealed that fast-recovering sites (South Batee and Bunta) possess high recovery capacity when pressure decreases, suggesting inherent reef resilience at these locations. In contrast, stagnating or phase-shifting sites (Lampuuk and Lhoknga) require targeted management interventions to mitigate environmental stressors. Fish Biomass and Richness SIMPER analysis revealed the highest Bray-Curtis dissimilarity in fish assemblages at South Batee Island NTZ (68.92%), Lampuuk (23.82%), Lhoknga (23.74%), and Bunta Island (12.76%). Fish assemblages at Lhoknga across both years were dominated by three species: Aeoliscus strigatus (29.79% contribution), Dascyllus carneus (21.28%), and Chromis dimidiata (8.51%). At Lampuuk, Caesio teres and Chromis caudalis contributed to community dissimilarity, accounting for 25.99% and 19.77%, respectively. South Batee Island exhibited a distinct species composition, with Neopomacentrus filamentosus (13.67%), Chromis viridis (9.11%), and Naso caeruleacauda (6.38%) being the most abundant species. To visualize these compositional shifts, Figure 4 details the relative abundance of dominant fish species and highlights the specific contributors to community dissimilarity. PERMANOVA analysis indicated that fish community composition did not change significantly between 2018 and 2024 (F = 0.36; p = 0.89). Although coral reef condition exhibited spatial variation, fish community structure remained stable over the six-year monitoring period. Fish species richness rose on average from 22 species in 2018 to 29 species in 2024, but paired t-tests showed this increase lacked statistical significance (p = 0.49; Cohen's d = 0.52). South Batee Island drove this medium effect size through an exceptional gain of 35 species (140% increase), while the other three sites experienced declines in species richness. Total fish abundance showed no significant difference between monitoring periods (p = 0.83; Cohen's d = 0.15), with means dropping slightly from 313 individuals (2018) to 299 individuals (2024). Spatial patterns revealed that Lhoknga and Lampuuk suffered abundance declines of 34.3% and 32.8%, respectively, while Bunta Island and South Batee Island gained 30.4% and 27.3%, respectively. Fish density (individuals/ha) exhibited no significant change between 2018 and 2024 (mean difference = 290 ind. ha⁻¹; p = 0.83; Cohen's d = 0.15), as means fell from 6,270 ind. ha⁻¹ to 5,980 ind. ha⁻¹. Lhoknga and Lampuuk drove the general decline pattern (-34.3% and -32.8%, respectively), whereas Bunta Island and South Batee Island achieved density increases. Mean fish biomass dropped from 295.1 kg ha⁻¹ (2018) to 224.4 kg ha⁻¹ (2024), yet statistical tests confirmed this difference lacked significance (p = 0.43; Cohen's d = 0.59). This medium effect size indicates a substantial reduction in biomass, although it is not statistically significant. Lhoknga, Lampuuk, and South Batee Island recorded biomass declines of 25.13%, 34.11%, and 43.10%, respectively, while Bunta Island alone experienced a gain of 11.95%. To further elucidate the stability and turnover of fish assemblages, Figure 5 visualizes the flow of species composition between the two monitoring periods and the trophic level of the composition. The Sankey diagram tracks changes in fish community composition across four no-take zones between 2018 and 2024. Bunta Island shows the highest temporal stability, with consistent gray flows and minimal species turnover, whereas Lhoknga and Lampuuk exhibit weakening communities, indicated by thinning gray bands and red streams that terminate in 2018. In contrast, South Batee Island demonstrates clear recovery, with thick green flows in 2024 that represent successful colonization by new species and only limited species loss. Coral reef fish biomass declined on average by 51%, dropping from 0.653 kg ha⁻¹ in 2018 to 0.315 kg ha⁻¹ in 2024. Bunta Island consistently recorded the highest fish biomass in both 2018 and 2024, demonstrating that the NTZ at this site maintained relatively stable and supportive habitat conditions. South Batee Island experienced the sharpest total biomass decline of 43% over the six years, indicating higher ecosystem vulnerability. While sustainable-use MPAs are expected to enhance fish biomass and food security (Viana et al., 2024), our findings of declining biomass indicate local enforcement gaps. The divergent trajectories of fish biomass and the associated shifts in dominant species are plotted in Figure 6. A declining trend in fish biomass and shifts in species dominance across adjacent no-take zones was observed, showing that spatial proximity does not guarantee ecological uniformity. Biomass visualizations indicate that herbivorous and omnivorous species present in 2018 increasingly gave way to corallivorous species by 2024, particularly at sites where biomass declined, strongly signalling deteriorating coral reef habitat quality, given the dependence of Chaetodon trifasciatus on healthy coral. Across sites, Caranx melampygus exhibited the most significant increase in biomass, while Acanthurus lineatus showed the largest decline in biomass. Species occurrence analysis further indicates uneven dynamics in the reef fish community, with South Batee Island recording the highest community turnover and other sites losing key indicator species, collectively demonstrating substantial spatial and temporal variability in the effectiveness of NTZs. These results suggest that the establishment of NTZs alone does not guarantee ecological recovery or that the NTZ is not being fully enforced. The Shannon diversity index (H′) across all sites averaged 2.42 ± 0.41 in 2018 and increased to 2.81 ± 0.40 in 2024, indicating the maintenance of moderate diversity levels despite fluctuations in total abundance. South Batee Island demonstrated the most pronounced recovery, with H′ increasing from 2.78 to 3.44 (ΔH′ = +0.66), accompanied by a decrease in the dominance index (C) from 0.08 to 0.05, suggesting a more even species distribution and enhanced community complexity. Conversely, sites experiencing abundance declines (Lhoknga: -82 individuals; Lampuuk: -143 individuals) maintained stable diversity and evenness values (E = 0.83-0.89), indicating that compositional structure remained resilient despite numerical reductions. Bunta Island showed concurrent increases in abundance (+56 individuals) and diversity (ΔH′ = +0.09), suggesting active recruitment and improved habitat quality. Across all sites, dominance indices remained low (C < 0.15). Temporal Dynamic of Water Quality Water quality parameters within the Marine Protected Area (MPA) exhibited significant monotonic trends over the 2018–2024 period, as quantified by the non-parametric Sen's slope. Sea surface temperature displayed a stable increase of 0.07 °C yr⁻¹, rising from 29.54 °C to 30.34 °C, indicative of climate-driven warming that may exacerbate thermal stress on coral communities. In contrast, salinity declined at -0.1275 psu yr⁻¹ to 32.1 psu, accompanied by mild pH acidification (-0.002 units yr⁻¹ to 8.01) and dissolved oxygen depletion (-0.175 mol m⁻³ yr⁻¹ to 200.7 mol m⁻³). Nutrient dynamics were heterogeneous, with nitrate rising moderately (0.0036 mol m⁻³ yr⁻¹ to 0.0642 mol m⁻³) and phosphate surging more sharply (0.0011 mmol m⁻³ yr⁻¹ to 0.0174 mmol m⁻³), likely attributable to terrestrial runoff from Aceh Besar Regency and Banda Aceh City, which could precipitate eutrophication and trophic disequilibria. Long-term trends in key environmental parameters, which underpin the observed biological responses, are depicted in Figure 7. To understand the potential synergistic effects of these stressors, the interdependencies among environmental variables were statistically evaluated, as shown in Table 3 using Pearson correlation coefficients. Table 3 . Pearson correlation coefficients among seawater quality parameters Parameters Sea Temperature Salinity pH DO Nitrate Phosphate Sea Temperature 1.000 Salinity -0.584 1.000 pH -0.965 0.515 1.000 DO -0.165 0.243 0.000 1.000 Nitrate -0.069 -0.463 0.199 0.127 1.000 Phosphate 0.673 -0.387 -0.788 0.430 -0.011 1.000 Sea temperature emerges as the dominant driver among water quality parameters, exhibiting a robust negative correlation with pH (r = -0.965) and a moderately strong positive correlation with phosphate (r = 0.673). pH, in turn, wields considerable sway over phosphate (r = -0.788) and salinity (r = 0.515). By contrast, nitrate stands out as the least impactful element, yielding correlation coefficients near zero or merely weak (r < 0.2) across all other variables such as sea temperature (r = -0.069), pH (r = 0.199), and phosphate (r = -0.011). Dissolved oxygen, too, plays a subdued role, revealing only feeble ties (r < 0.3) to most parameters, save for its modest positive connection to phosphate (r = 0.430). The observed SST rise in Aceh mirrors the increasing frequency of marine heatwaves linked to bleaching events across the Indonesian archipelago (Ningsih et al. 2025), and this thermal stress likely contributed to the observed benthic community shifts, consistent with patterns documented in Raja Ampat reefs (Aji et al. 2024). Elevated nutrient levels indicate localized eutrophication, which can fundamentally alter microbenthic reef communities (Girard et al., 2025). The decline in dissolved oxygen is consistent with global trends of reef deoxygenation under ocean warming and may exacerbate metabolic stress in reef organisms (Pezner et al. 2023). Performance (before–after) No statistically significant changes were detected in live coral cover, dead coral cover, species richness, total individual abundance, fish abundance, or biomass between 2018 and 2024 across all no-take zones (paired t-test, all p > 0.4). While some parameters showed positive trends, all confidence intervals included zero, and effect sizes were at most moderate. The aggregate ecological changes across the four NTZs are summarized in Table 4. To comprehensively evaluate NTZ effectiveness, key ecological indicators were compared before (2018) and after (2024) protection implementation across all four sites. The aggregated and site-specific changes are presented in Table 4. Table 4. Summary of ecological changes across four NTZs (2018–2024) Parameter 2018 (mean) 2024 (mean) Mean difference (Δ) Δ (%) 95% CI t p-value Cohen’s d Live coral cover (%) 41.8 49.11 7.31 17.5 (-22.01, 36.62) 0.61 0.56 0.43 Dead coral cover (%) 25.51 22.36 -3.15 -12.4 (-23.47, 29.76) 0.29 0.78 0.2 Species richness 22 29.5 7.5 34.1 (-17.68, 32.68) 0.73 0.49 0.52 Fish abundance (ind. ha⁻¹) 6270 5980 -290 -4.6 (-2958, 3539) 0.22 0.83 0.15 Biomass (kg ha⁻¹) 295.1 224.4 -70.7 -24 (-135.47, 276.85) 0.84 0.43 0.59 Note: Δ% calculated from aggregate means. Detailed site-specific data are provided in Supplementary Table S1. As shown in Table 4, live coral cover increased by an average of 17.5%, while fish biomass declined by 24.0%. However, none of these changes were statistically significant at the network level (*p* > 0.05), indicating highly variable site-specific trajectories and limited overall effectiveness of protection measures during the six-year study period. These findings suggest that there is no robust evidence of ecological recovery during the study period in these no-take zones. The ecosystem performance was influenced by water quality changes, with a 2.71% increase in sea temperature. Other parameters showed decreased salinity (2.43%), pH (0.37%), dissolved oxygen (0.35%), nitrate (12.5%), and phosphate (33.33%). Percentage changes in ecological indicators between 2018 and 2024 revealed heterogeneous recovery trajectories (Figure 8). Live coral increased across all sites (Δ = +10% to +75%), accompanied by dead coral reductions (Δ = -15% to -75%). Fish abundance demonstrated divergent site responses (Δ = -50% to +40%), with South Batee Island and Bunta Island exhibiting positive community expansion while Lhoknga and Lampuuk experienced biomass contractions (Δ = -35% to -45%). Trophic group changes mirrored site-specific fish community trajectories, with herbivore densities ranging from a 55% decrease to a 30% increase across sites. To investigate the mechanistic links between habitat improvement and fish community responses, Figure 9 presents pairwise correlations of the observed ecological performances. A strong, statistically significant negative correlation was identified between the reduction in dead coral cover and the increase in fish species richness (r = -0.950; p = 0.050), indicating that substrate recovery directly facilitates ichthyofaunal diversification. A strong negative relationship exists between changes in live and dead coral cover (r = -0.867), further confirming that live coral expansion effectively displaces degraded substrate. Temporal analysis reveals a complex trajectory where increases in live coral do not immediately result in biomass gains (r = -0.801; p = 0.199). This discrepancy likely reflects a time-lag response in recovery. These findings underscore that substrate improvement is a critical precursor for biodiversity recovery and that biomass accumulation follows a delayed trajectory, necessitating long-term monitoring to capture the full extent of ecosystem benefits. Discussion The uneven ecological responses across Aceh Besar’s NTZs highlight the complexity of marine conservation. The significant decline in biomass at South Batee Island (43%) aligns with studies showing that the effectiveness of NTZs depends on enforcement and habitat quality (Edgar et al. 2014). Comparative evidence from Tapanuli Tengah NTZs in North Sumatra demonstrates this clearly: well-enforced sites achieve 64–69% hard coral cover, compared to 13–39% in non-protected areas, with fish abundances 3-4 times higher. In contrast, Bunta Island's biomass increase (11.9%) suggests stable habitat conditions, possibly due to lower anthropogenic pressures. The shift from herbivore-omnivore to corallivore dominance indicates declining coral health, consistent with global trends in degraded reefs (Hughes et al. 2007). This contrasts with the Anambas Islands, where adequate protection led to significant biomass recovery (Putra et al. 2021), further highlighting the critical role of enforcement. Weak enforcement, as evidenced by reported illegal fishing in Aceh Besar (Halim et al. 2019), likely exacerbates these declines. Adaptive management, including stricter patrols and habitat restoration, is critical to enhancing NTZ outcomes. Limitations include the lack of environmental data (e.g., sedimentation rates), which may influence observed trends. This analysis contends that future MPA establishment must embed operational commitments into design phases, rejecting the conventional approach of treating implementation as a secondary concern. This aligns with calls for shifting focus from merely expanding MPA coverage to enhancing the management effectiveness and connectivity of existing networks (White et al. 2014, 2021). Aceh Besar's NTZ network provides compelling evidence that operational rigor, not legal designation alone, determines conservation outcomes. The before and after observation window captures only early establishment dynamics and proves insufficient to detect long-term recovery trajectories. This study lacked control sites and operated with limited compliance enforcement data, which constrains our ability to partition the relative contributions of protection versus external stressors. Nevertheless, these constraints illuminate critical research priorities. Three essential research directions are proposed to advance marine conservation science: (1) implement long-term adaptive monitoring frameworks spanning ≥15 years with replicated control sites to quantify recovery trajectories; (2) integrate socio-economic and ecological data to link livelihood changes with ecological outcomes mechanistically; and (3) design matched experimental comparisons between high-enforcement and low-enforcement MPA networks across Indonesia's marine protected area system to isolate enforcement effects. For severely degraded sites, active restoration interventions could accelerate ecological recovery (Aja et al. 2025). Conclusion Six-year monitoring across four no-take zones demonstrates that regulatory designation alone fails to guarantee ecosystem restoration. Indeed, the lack of significant ecological recovery suggests that these areas may never have functioned as effectively as enforced no-take zones, undermining the premise of protection itself. Uneven ecological responses across sites are revealed: live coral cover increased at three locations. In comparison, fish biomass and abundance declined at three locations, with no statistically significant changes detected across measured parameters (all p > 0.4). The results indicate that enforcement intensity, habitat quality, and climate stress substantially determine the effectiveness of NTZs more than legal status. These findings challenge Indonesia's current marine conservation strategy, despite the country's national targets to establish 30 million hectares of protected areas by 2030. The data unequivocally show that protection without robust enforcement, active habitat restoration, and climate adaptation interventions produces limited ecological returns. Declarations Ethics and Consent to Participate Field surveys were conducted under Research Permit No. 500.5/2966, issued by the Department of Marine and Fisheries, Aceh Besar Regency, Indonesia. No experimental manipulation of animals or collection of endangered species was undertaken, and all surveys were conducted in accordance with applicable local and national regulations. Competing interests The authors declare no competing interests. Funding This research was supported by the Indonesian Education Scholarship (BPI), managed by the Center for Higher Education Funding and Assessment (Ministry of Higher Education, Science, and Technology) and funded by the Endowment Fund for Education Agency (LPDP), Ministry of Finance, Republic of Indonesia. The funders had no role in research design, data collection, analysis, interpretation, or preparation of the manuscript. Author Contribution R.F. conceived the study, designed the methodology, conducted the investigation, performed formal analysis and data curation, wrote the original draft, prepared visualizations, and managed project administration. F.Y., Z.Z., and G.Y. contributed to conceptualization, methodology, and supervision. A.T.W. contributed to conceptualization and validation. All authors (R.F., F.Y., Z.Z., G.Y., and A.T.W.) participated in writing – review & editing and approved the final manuscript. Acknowledgement This work was supported by the Indonesian Education Scholarship (BPI), managed by the Center for Higher Education Funding and Assessment (Ministry of Higher Education, Science, and Technology) and funded by the Endowment Fund for Education Agency (LPDP), Ministry of Finance, Republic of Indonesia. Data Availability The datasets generated and analysed during the current study are provided as Supplementary Materials accompanying this submission. Benthic cover data (Supplementary Data S1, S2), fish community data (S3, S4), water quality time series (S5), and statistical outputs (S6) are available with the published article or from the corresponding author on reasonable request. 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17:46:43","extension":"html","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":99079,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/dd3b97f25dd8fd144c9f07e2.html"},{"id":100709380,"identity":"df66905a-0a8b-42e2-ba17-64c909e0a711","added_by":"auto","created_at":"2026-01-20 17:43:40","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":389589,"visible":true,"origin":"","legend":"\u003cp\u003eMap of the Marine Protected Areas (MPAs) in Aceh Besar, Indonesia. The map shows the spatial distribution of management zones, including no-take zones (red), utilization zones (green), and sustainable fishing zones (blue). Black dots represent sampling stations where ecological surveys were conducted between 2018 and 2024.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/b8cc5c46658a7f2c9d868e21.png"},{"id":100709549,"identity":"b5d887dc-1723-4479-8db4-d508e7328ae5","added_by":"auto","created_at":"2026-01-20 17:45:28","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":315239,"visible":true,"origin":"","legend":"\u003cp\u003eBenthic and geomorphic zonation maps of the five NTZ sites: (a) Lhoknga, (b) Lampuuk, (c) Bunta Island, (d) South Batee Island, and (e) Lhok Keutapang. Benthic categories include coral/algae, rock, rubble, sand, and seagrass, while geomorphic zones comprise back reef slope, reef flat, lagoon, and terrestrial reef flat areas.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/7e0fe1c92c162a68e081812c.png"},{"id":100709985,"identity":"fc248866-44dd-486f-af3c-57f6faa1746d","added_by":"auto","created_at":"2026-01-20 17:46:52","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":304950,"visible":true,"origin":"","legend":"\u003cp\u003eEcological responses of benthic substrate composition at the six NTZ sites between 2018 and 2024. Stacked bars show the relative proportions of each benthic category, while dotted lines highlight the temporal dynamics between live coral (C) and dead coral (DC). Values represent the mean percentage cover per site from benthic transect surveys.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/a60c63729f6be9e978f8b2f1.png"},{"id":100710293,"identity":"5f0b3e33-71ba-4384-98ad-8bdce9f3d31b","added_by":"auto","created_at":"2026-01-20 17:50:07","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":639328,"visible":true,"origin":"","legend":"\u003cp\u003eTop 10 Species (before–after)\u003cstrong\u003e \u003c/strong\u003eRelative abundance (%) Contribution of each species to the total fish community. Percentage values on the right indicate the magnitude of change (increase ↑ or decrease ↓) for each species.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/b9019fb411947fb1895cb3b7.png"},{"id":100710244,"identity":"3fbac91e-89b6-4bcd-91ee-84474149a5ec","added_by":"auto","created_at":"2026-01-20 17:49:34","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":382128,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal dynamics and trophic composition of reef fish communities (2018–2024). (a) Sankey diagram illustrating changes in species composition, with gray flows representing stable species and colored flows indicating turnover (red: losses; green: recruitment). South Batee Island demonstrates substantial recovery in 2024. (b) Trophic group composition shows a decline in herbivores (2018: 31–47% to 2024: 23–50%) and an increase in carnivores, indicating deteriorating reef habitat quality.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/ff3aa1f3c4a0f168664fba49.png"},{"id":100709589,"identity":"322629fc-ba01-4bfb-8732-b43b85e96d22","added_by":"auto","created_at":"2026-01-20 17:45:38","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":246971,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal shifts in biomass and dominant reef fish species across NTZ sites between 2018 and 2024. Lines connect changes in biomass (kg ha⁻¹) of the most abundant species per site.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/bb75e66a95d9ba9ea3ffb458.png"},{"id":100710151,"identity":"3662b01a-6bd9-4406-9b72-6654a9266a8c","added_by":"auto","created_at":"2026-01-20 17:48:36","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":451210,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal trends and absolute changes of water quality parameters. Blue lines represent the annual means of sea temperature, salinity, pH, dissolved oxygen, nitrate, and phosphate, with red dashed lines indicating Sen’s slope trends. The bottom panel shows absolute changes (Δ 2018–2024).\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/2e549565bc425937f3cefa46.png"},{"id":100710168,"identity":"2a323d4a-7a3b-48fa-98d7-269756ea240f","added_by":"auto","created_at":"2026-01-20 17:48:45","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":175209,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePercentage change (Δ%) in ecological indicators across No-Take Zone (NTZ) sites between 2018 and 2024. Each panel represents a site: (a) Lhoknga, (b) Lampuuk, (c) Bunta Island, and (d) South Batee Island-illustrating relative changes in live coral (LC), dead coral (DC), fish species richness (SP), total individuals (TI), fish abundance (FA), biomass (BM), and trophic groups including herbivores (HV), omnivores (OM), carnivores (CA), and unclassified species (UN).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/23342074076f7d77f118898a.png"},{"id":100710391,"identity":"b6a72cfb-730a-42ca-bf10-d3c5455ac3a4","added_by":"auto","created_at":"2026-01-20 17:51:07","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":286417,"visible":true,"origin":"","legend":"\u003cp\u003ePairwise correlations of NTZ performance changes (2018–2024). Scatter plots show relationships between changes in coral cover, species richness, abundance, and biomass across four sites. Dashed lines: linear regression; shaded areas: 95% CI. r and p-values shown in subtitles. Strongest correlation: dead coral vs. species richness (r = -0.950; p = 0.050*).\u003c/p\u003e","description":"","filename":"floatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/a1a1ac9e9e3f749fb9fc490b.png"},{"id":100719289,"identity":"dd98be2b-9b61-4950-97d0-9ae21acc3c89","added_by":"auto","created_at":"2026-01-20 19:26:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3955933,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8589881/v1/03f17baf-044d-4c09-af2f-bd08152bf06e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"From Paper Parks to Real Protection: Ecological Performance of No-Take Zones in Aceh Besar, Indonesia","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMarine ecosystems and their associated biota have been negatively impacted by climate change (Venegas et al. 2023), which is further exacerbated by increasing anthropogenic pressures (Zhao et al. 2025). To protect marine ecosystems, the International Union for Conservation of Nature has developed the concept of Marine Protected Areas (Grorud-Colvert et al. 2021). MPAs are established to conserve biodiversity, maintain ecosystem functions, and ensure sustainable resource utilization through an ecosystem-based approach to marine area management. MPA planning and management is often comprised of zoning systems, ranging from single-use to multi-use designations (Horta e Costa et al. 2016).\u003c/p\u003e \u003cp\u003eIn the MPA framework, no-take zones (NTZs) are specific types of marine protected areas where all extractive activities are strictly prohibited (Costello and Ballantine 2015). NTZs in a marine reserve provide the best protection for ocean ecosystems (Sala and Giakoumi 2018) and are supported by recent findings (Hopf et al. 2024). No-take zones have proven more effective at increasing fish abundance and biomass compared to open waters, with evidence derived from various long-term and short-term studies. Early research demonstrated that no-take zones can increase species populations (Alcala 1988) and accelerate the recovery of depleted fish stocks. Subsequent findings revealed that no-take zones not only strengthen fish stocks within the zone (Halpern 2003) But also promote the spillover of adult fish and larvae to surrounding areas (Gell and Roberts 2003; Russ et al. 2004). No-take zones generally exhibit higher biomass compared to open waters (Lester 2009), with target species abundance consistently higher within no-take zones due to the absence of fishing pressure (Halpern et al. 2009). Recent research indicates that no-take zones are effective in restoring biomass and recovering ecosystem ecological functions. Biomass increases of 463% were observed in Cabo Pulmo National Park over approximately 10 years (Aburto-Oropeza et al. 2011). NTZs in Tapanuli Tengah (North Sumatra) achieve significantly higher coral cover (64\u0026ndash;69%) and fish abundance (10,520\u0026ndash;19,440 ind. ha⁻\u0026sup1;) compared to non-protected areas (Harahap et al. 2025).\u003c/p\u003e \u003cp\u003eDespite their demonstrated effectiveness across multiple contexts, although no-take zones are recognized as effective, their success often varies across locations due to influences from zone size (Claudet 2008; Espinosa-Andrade, 2020; Ohayon et al. 2021), habitat conditions (Rees et al. 2018; Baliwe et al. 2022), enforcement level (Campbell et al. 2012; Advani et al. 2015) and community engagement (Kura et al. 2023).\u003c/p\u003e \u003cp\u003eThis study focuses on Aceh Besar Regency, which faces the Indian Ocean directly, and is one of Indonesia's marine protected area implementing a multi-use zoning system based on resource utilization (Muhammad et al. 2021). This zoning system comprises: (1) No-take zones, (2) Sustainable Fisheries Zones, (3) Utilization Zones, and (4) Other Zones. The area is utilized by approximately 4,577 fishers, the majority of whom are classified as small-scale fishers according to Indonesian definitions (Halim et al. 2019).\u003c/p\u003e \u003cp\u003eHowever, despite the implementation of this conservation framework, significant knowledge gaps persist regarding the ecological outcome in Aceh Besar Regency. Specific evaluations regarding the effectiveness of no-take zones remain unavailable in the literature or in management reports. Scientific data concerning the ecosystems and resources within the NTZs, particularly those implemented between 2018 (proposed by the local Government) and 2020 (established by the central Government), remains unavailable to date. Although the Indonesian Government has established formal monitoring frameworks for MPA effectiveness, namely the Technical Guidelines for Evaluating the Management Effectiveness of Aquatic, Coastal, and Small Islands Conservation Areas (E-KKP3K), subsequently renamed as the Evaluation of the Effectiveness of Conservation Area Management (EVIKA), these frameworks have not been rigorously implemented in practice. This information gap hinders monitoring and evaluation efforts, thereby limiting understanding of the extent to which existing conservation strategies have been successful or unsuccessful.\u003c/p\u003e \u003cp\u003eTo address these critical research gaps and provide empirical evidence for this understudied system, this study aims to evaluate the response of coral reef ecosystems and fish resources in no-take zones between 2018 and 2024 using a before\u0026ndash;and\u0026ndash;after approach. This research contributes to understanding ecological performance in adjacent NTZs, providing empirical evidence essential for evaluating conservation efficacy in tropical systems. This investigation addresses whether the implementation of no-take zones during this period successfully enhanced ecosystem conditions and fish resources, thereby informing future management and policy decisions for marine conservation in Indonesia and beyond.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eA before\u0026ndash;and\u0026ndash;after comparative framework was applied to quantify ecological changes in four NTZs in Aceh Besar, Indonesia: Lhoknga, Lampuuk, Bunta Island, and South Batee Island. Baseline field surveys conducted in 2018 were compared with resurveys in 2024. The NTZ at Tuan Island was excluded from temporal analysis due to its relocation to Lhok Keutapang in 2024.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eBenthic composition was quantified using photographic transects (50 m) and processed using Coral Point Count with Excel extensions (CPCe) (Kohler and Gill 2006). Each image was annotated with a 25-point uniform grid, producing approximately 1,875 points per site. Benthic categories included \u003cem\u003elive coral, dead coral, dead coral with algae, rubble, soft coral, sponge, sand, rock, and other substrates\u003c/em\u003e. Reef fish communities were assessed using Underwater Visual Census (UVC)(English et al. 1998) along two replicated belt transects per site, each spanning 100 \u0026times; 5 m (Samoilys and Carlos 2000). Fish biomass (kg ha⁻\u0026sup1;) was estimated from total length measurements using species-specific length-weight relationships \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:W={a\\:L}^{b}\\)\u003c/span\u003e\u003c/span\u003e with parameters obtained from FishBase (Ernawati et al. 2024). To contextualize ecological responses within the broader oceanographic environment, water quality parameters were derived including sea surface temperature (\u0026deg;C), salinity (practical salinity units, psu), pH, dissolved oxygen (mmol m⁻\u0026sup3;), nitrate (NO₃⁻), and phosphate (PO₄\u0026sup3;⁻) from Marine Copernicus datasets (CMEMS GLO12) spanning 2018\u0026ndash;2024. This incorporation captured spatial and temporal variability in water quality parameters across NTZs.\u003c/p\u003e \u003cp\u003eTemporal differences between 2018 and 2024 were examined using paired t-tests and Mann-Whitney U tests, depending on the data characteristics, with effect sizes reported as Cohen's d. Fish community composition was evaluated using PERMANOVA (Bray-Curtis dissimilarity; 9,999 permutations), followed by Similarity Percentage (SIMPER) analysis to identify the contributing factors to temporal dissimilarity. Relationships among water quality variables were assessed using the Pearson correlation coefficient. All statistical analyses were performed in PAST v4.17 (Hammer et al. 2001) with significance determined at α\u0026thinsp;=\u0026thinsp;0.05. The spatial configuration of the Marine Protected Area network, illustrating the proximity of sampling stations to diverse management zones, is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Specific operational details, including the exact coordinates and dimensions of the designated no-take zones, are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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\u003eStudy Sites within No-Take Zone Marine Protected Areas\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=\"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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eNo-take zone\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSize (ha)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eLat-Long\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eDate Survey\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAfter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBefore\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLhoknga\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.21694\u0026deg; E, 5.43385\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024/07/12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2018/02/03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLampuuk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e90.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.21677\u0026deg; E, 5.48455\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024/07/12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2018/02/03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBunta Island\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e105.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.15025\u0026deg; E, 5.55320\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024/07/12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2018/02/03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSouth Batee Island\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e124.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.33340\u0026deg; E, 5.95338\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024/11/30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2018/02/20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLhok Keutapang\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.20022\u0026deg; E, 5.55232\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024/11/30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTuan Island\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95.24817\u0026deg; E, 5.56403\u0026deg; S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2018/02/20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003ch2\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cem\u003eBenthic and Geomorphic Characteristics in the No-take zone\u003c/em\u003e\u003c/h2\u003e\n\u003cp\u003eSatellite imagery from the Allen Coral Atlas provided baseline data on benthic cover within the designated NTZs. These data revealed that each NTZ exhibited distinct ecological characteristics from the outset of its designation. Although relatively small in size, the NTZ in Lhoknga displayed the highest benthic cover percentage. In contrast, the larger NTZ in South Batee Island showed lower benthic cover. These differences are likely attributed to geomorphological factors, such as the dominance of reef slopes and inner reef flats in Lhoknga and Lampuuk, compared to the prevalence of terrestrial reef flats and shallow lagoons in South Batee Island and Lhok Keutapang. Geomorphological analysis of five study sites revealed spatial heterogeneity in reef structure, with reef slope as the dominant (Lampuuk: 99.45%; Lhoknga: 73.04%; Bunta Island: 53.72%; South Batee Island: 49.53%) and terrestrial reef flat in one location (Lhok Keutapang: 46.23%). These initial observations reflect the pre-existing condition of coral reef habitats before the full implementation of protection measures. They should not be interpreted as the direct outcome of conservation efforts. A detailed quantitative breakdown of the initial benthic composition and geomorphic zones for each site is provided in\u003cstrong\u003e\u0026nbsp;Table 2.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u0026nbsp;\u003c/strong\u003eBenthic composition and Geomorphic zonation within no-take zones (NTZs).\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSubstrate component\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eUnit\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLhoknga\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLampuuk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBunta Island\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSouth Batee Island\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLhok Keutapang\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNTZ size\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e105.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e124.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e66.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBenthic cover\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCoral/Algae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRock\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRubble\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.84\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSeagrass\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTotal benthic area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e% of NTZ area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e63.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e31.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28.95\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGeomorphic zone\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eReef Slope\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.61\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTerrestrial Reef Flat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e20.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eInner Reef Flat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOuter Reef Flat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eBack Reef Slope\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eShallow Lagoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDeep Lagoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePlateau\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTotal geomorphic area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eha\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e59.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e34.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e% of NTZ area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e71.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e20.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e56.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e29.25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe data reveal fundamental structural differences between sites, with Lhoknga dominated by reef slopes while South Batee Island features extensive terrestrial reef flats. To visualize this spatial heterogeneity, Figure 2 maps the distribution of benthic habitats and geomorphic features across the five study sites.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cem\u003eCoral Cover Change\u003c/em\u003e\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eBenthic community composition analysis identified distinct ecological response patterns. Bunta Island and South Batee Island demonstrated the highest recovery capacity, sustaining high and stable live coral cover (\u0026gt;60%) throughout the 6-year study period. South Batee Island exhibited an exceptional reversal in ecological performance. In 2018, severe reef degradation, characterized by the dominance of dead coral, was apparent. By 2024, recovery was evident through a decrease in dead coral cover, accompanied by an increase in live coral cover. This rapid reversal indicates high recovery potential and suggests adequate larval supply. Both no-take zones demonstrated high ecological resilience, characterized by fast recovery rates. The temporal dynamics of benthic substrate composition, contrasting the shifts between live and dead coral cover over the six years, are illustrated in Figure 3.\u003c/p\u003e\n\u003cp\u003eLampuuk NTZ demonstrated positive but gradual recovery. This recovery rate was attributed to persistent environmental stress, particularly sedimentation pressure. Sedimentation at this site originated from natural terrestrial runoff during the rainy season and local hydrographic and oceanographic dynamics that accumulated sediment. Lampuuk exemplified a location with a positive but constrained recovery trajectory. Lhoknga NTZ also demonstrated positive recovery patterns. However, rubble persistence remained high despite increasing coral cover. Observations indicate this site remains in an early recovery phase with incomplete substrate restabilization. Lhok Keutapang NTZ, with limited 2024 data, displayed moderate reef status characterized by balanced composition between live coral and consolidated substrates (rock). However, the presence of rubble indicates physical stress or degradation events. Stable, hard substrate availability (such as rock) offers potential for prospective coral expansion, provided physical stability is maintained.\u003c/p\u003e\n\u003cp\u003eStatistical analysis of live coral cover across four no-take zones (Lhoknga, Lampuuk, Bunta Island, and South Batee Island) revealed no significant temporal changes. Although mean cover increased from 41.8% to 49.1%, paired t-tests demonstrated this increase was not statistically significant (p = 0.56; Cohen\u0026apos;s d = 0.43). Substantial spatial variability characterized the study sites. Lhoknga and Lampuuk experienced live coral cover declines of 14.7% each, while South Batee Island exhibited the highest increase at 77.7%. Dead coral cover similarly showed no significant temporal change (p = 0.78; Cohen\u0026apos;s d = 0.2), despite pronounced site-level differences. Lhoknga increased 34.5% while South Batee Island decreased 38.5%. This spatial heterogeneity in recovery trajectory highlights the importance of understanding site-specific reef resilience mechanisms and the effectiveness of science-based marine management. Recovery trajectories revealed that fast-recovering sites (South Batee and Bunta) possess high recovery capacity when pressure decreases, suggesting inherent reef resilience at these locations. In contrast, stagnating or phase-shifting sites (Lampuuk and Lhoknga) require targeted management interventions to mitigate environmental stressors.\u003c/p\u003e\n\u003ch2\u003e\u003cem\u003e\u0026nbsp;\u003cstrong\u003eFish Biomass and Richness\u003c/strong\u003e\u003c/em\u003e\u003c/h2\u003e\n\u003cp\u003eSIMPER analysis revealed the highest Bray-Curtis dissimilarity in fish assemblages at South Batee Island NTZ (68.92%), Lampuuk (23.82%), Lhoknga (23.74%), and Bunta Island (12.76%). \u0026nbsp;Fish assemblages at Lhoknga across both years were dominated by three species: \u003cem\u003eAeoliscus strigatus\u003c/em\u003e (29.79% contribution), \u003cem\u003eDascyllus carneus\u003c/em\u003e (21.28%), and \u003cem\u003eChromis dimidiata\u003c/em\u003e (8.51%). At Lampuuk, \u003cem\u003eCaesio teres\u003c/em\u003e and \u003cem\u003eChromis caudalis\u003c/em\u003e contributed to community dissimilarity, accounting for 25.99% and 19.77%, respectively. South Batee Island exhibited a distinct species composition, with \u003cem\u003eNeopomacentrus filamentosus\u003c/em\u003e (13.67%), \u003cem\u003eChromis viridis\u003c/em\u003e (9.11%), and \u003cem\u003eNaso caeruleacauda\u003c/em\u003e (6.38%) being the most abundant species. To visualize these compositional shifts, Figure 4 details the relative abundance of dominant fish species and highlights the specific contributors to community dissimilarity.\u003c/p\u003e\n\u003cp\u003ePERMANOVA analysis indicated that fish community composition did not change significantly between 2018 and 2024 (F = 0.36; p = 0.89). Although coral reef condition exhibited spatial variation, fish community structure remained stable over the six-year monitoring period. Fish species richness rose on average from 22 species in 2018 to 29 species in 2024, but paired t-tests showed this increase lacked statistical significance (p = 0.49; Cohen\u0026apos;s d = 0.52). South Batee Island drove this medium effect size through an exceptional gain of 35 species (140% increase), while the other three sites experienced declines in species richness. Total fish abundance showed no significant difference between monitoring periods (p = 0.83; Cohen\u0026apos;s d = 0.15), with means dropping slightly from 313 individuals (2018) to 299 individuals (2024). Spatial patterns revealed that Lhoknga and Lampuuk suffered abundance declines of 34.3% and 32.8%, respectively, while Bunta Island and South Batee Island gained 30.4% and 27.3%, respectively. Fish density (individuals/ha) exhibited no significant change between 2018 and 2024 (mean difference = 290 ind. ha⁻\u0026sup1;; p = 0.83; Cohen\u0026apos;s d = 0.15), as means fell from 6,270 ind. ha⁻\u0026sup1; to 5,980 ind. ha⁻\u0026sup1;. Lhoknga and Lampuuk drove the general decline pattern (-34.3% and -32.8%, respectively), whereas Bunta Island and South Batee Island achieved density increases. Mean fish biomass dropped from 295.1 kg ha⁻\u0026sup1; (2018) to 224.4 kg ha⁻\u0026sup1; (2024), yet statistical tests confirmed this difference lacked significance (p = 0.43; Cohen\u0026apos;s d = 0.59). This medium effect size indicates a substantial reduction in biomass, although it is not statistically significant. Lhoknga, Lampuuk, and South Batee Island recorded biomass declines of 25.13%, 34.11%, and 43.10%, respectively, while Bunta Island alone experienced a gain of 11.95%. To further elucidate the stability and turnover of fish assemblages,\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eFigure 5 visualizes the flow of species composition between the two monitoring periods and the trophic level of the composition.\u003c/p\u003e\n\u003cp\u003eThe Sankey diagram tracks changes in fish community composition across four no-take zones between 2018 and 2024. Bunta Island shows the highest temporal stability, with consistent gray flows and minimal species turnover, whereas Lhoknga and Lampuuk exhibit weakening communities, indicated by thinning gray bands and red streams that terminate in 2018. In contrast, South Batee Island demonstrates clear recovery, with thick green flows in 2024 that represent successful colonization by new species and only limited species loss.\u003c/p\u003e\n\u003cp\u003eCoral reef fish biomass declined on average by 51%, dropping from 0.653 kg ha⁻\u0026sup1; in 2018 to 0.315 kg ha⁻\u0026sup1; in 2024. Bunta Island consistently recorded the highest fish biomass in both 2018 and 2024, demonstrating that the NTZ at this site maintained relatively stable and supportive habitat conditions. South Batee Island experienced the sharpest total biomass decline of 43% over the six years, indicating higher ecosystem vulnerability. While sustainable-use MPAs are expected to enhance fish biomass and food security (Viana et al., 2024), our findings of declining biomass indicate local enforcement gaps. The divergent trajectories of fish biomass and the associated shifts in dominant species are plotted in Figure 6.\u003c/p\u003e\n\u003cp\u003eA declining trend in fish biomass and shifts in species dominance across adjacent no-take zones was observed, showing that spatial proximity does not guarantee ecological uniformity. Biomass visualizations indicate that herbivorous and omnivorous species present in 2018 increasingly gave way to corallivorous species by 2024, particularly at sites where biomass declined, strongly signalling deteriorating coral reef habitat quality, given the dependence of \u003cem\u003eChaetodon trifasciatus\u003c/em\u003e on healthy coral. Across sites, \u003cem\u003eCaranx melampygus\u003c/em\u003e exhibited the most significant increase in biomass, while \u003cem\u003eAcanthurus lineatus\u003c/em\u003e showed the largest decline in biomass. Species occurrence analysis further indicates uneven dynamics in the reef fish community, with South Batee Island recording the highest community turnover and other sites losing key indicator species, collectively demonstrating substantial spatial and temporal variability in the effectiveness of NTZs. These results suggest that the establishment of NTZs alone does not guarantee ecological recovery or that the NTZ is not being fully enforced.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe Shannon diversity index (H\u0026prime;) across all sites averaged 2.42 \u0026plusmn; 0.41 in 2018 and increased to 2.81 \u0026plusmn; 0.40 in 2024, indicating the maintenance of moderate diversity levels despite fluctuations in total abundance. South Batee Island demonstrated the most pronounced recovery, with H\u0026prime; increasing from 2.78 to 3.44 (\u0026Delta;H\u0026prime; = +0.66), accompanied by a decrease in the dominance index (C) from 0.08 to 0.05, suggesting a more even species distribution and enhanced community complexity. Conversely, sites experiencing abundance declines (Lhoknga: -82 individuals; Lampuuk: -143 individuals) maintained stable diversity and evenness values (E = 0.83-0.89), indicating that compositional structure remained resilient despite numerical reductions. Bunta Island showed concurrent increases in abundance (+56 individuals) and diversity (\u0026Delta;H\u0026prime; = +0.09), suggesting active recruitment and improved habitat quality. Across all sites, dominance indices remained low (C \u0026lt; 0.15).\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003e\u003cem\u003e\u003cstrong\u003eTemporal Dynamic of Water Quality\u003c/strong\u003e\u003c/em\u003e\u003c/h2\u003e\n\u003cp\u003eWater quality parameters within the Marine Protected Area (MPA) exhibited significant monotonic trends over the 2018\u0026ndash;2024 period, as quantified by the non-parametric Sen\u0026apos;s slope. Sea surface temperature displayed a stable increase of 0.07 \u0026deg;C yr⁻\u0026sup1;, rising from 29.54 \u0026deg;C to 30.34 \u0026deg;C, indicative of climate-driven warming that may exacerbate thermal stress on coral communities. In contrast, salinity declined at -0.1275 psu yr⁻\u0026sup1; to 32.1 psu, accompanied by mild pH acidification (-0.002 units yr⁻\u0026sup1; to 8.01) and dissolved oxygen depletion (-0.175 mol m⁻\u0026sup3; yr⁻\u0026sup1; to 200.7 mol m⁻\u0026sup3;). Nutrient dynamics were heterogeneous, with nitrate rising moderately (0.0036 mol m⁻\u0026sup3; yr⁻\u0026sup1; to 0.0642 mol m⁻\u0026sup3;) and phosphate surging more sharply (0.0011 mmol m⁻\u0026sup3; yr⁻\u0026sup1; to 0.0174 mmol m⁻\u0026sup3;), likely attributable to terrestrial runoff from Aceh Besar Regency and Banda Aceh City, which could precipitate eutrophication and trophic disequilibria. Long-term trends in key environmental parameters, which underpin the observed biological responses, are depicted in Figure 7.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo understand the potential synergistic effects of these stressors, the interdependencies among environmental variables were statistically evaluated, as shown in Table 3 using Pearson correlation coefficients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e. Pearson correlation coefficients among seawater quality parameters\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eParameters\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eSea Temperature\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003eSalinity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003epH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003eDO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003eNitrate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003ePhosphate\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eSea Temperature\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eSalinity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e-0.584\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003epH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e-0.965\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.515\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eDO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e-0.165\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.243\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eNitrate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e-0.069\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e-0.463\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.199\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.127\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003ePhosphate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e0.673\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e-0.387\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e-0.788\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.430\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e-0.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSea temperature emerges as the dominant driver among water quality parameters, exhibiting a robust negative correlation with pH (r = -0.965) and a moderately strong positive correlation with phosphate (r = 0.673). pH, in turn, wields considerable sway over phosphate (r = -0.788) and salinity (r = 0.515). By contrast, nitrate stands out as the least impactful element, yielding correlation coefficients near zero or merely weak (r \u0026lt; 0.2) across all other variables such as sea temperature (r = -0.069), pH (r = 0.199), and phosphate (r = -0.011). Dissolved oxygen, too, plays a subdued role, revealing only feeble ties (r \u0026lt; 0.3) to most parameters, save for its modest positive connection to phosphate (r = 0.430). The observed SST rise in Aceh mirrors the increasing frequency of marine heatwaves linked to bleaching events across the Indonesian archipelago (Ningsih et al. 2025), and this thermal stress likely contributed to the observed benthic community shifts, consistent with patterns documented in Raja Ampat reefs (Aji et al. 2024). Elevated nutrient levels indicate localized eutrophication, which can fundamentally alter microbenthic reef communities (Girard et al.,\u0026nbsp;2025). The decline in dissolved oxygen is consistent with global trends of reef deoxygenation under ocean warming and may exacerbate metabolic stress in reef organisms (Pezner et al. 2023).\u003c/p\u003e\n\u003ch2\u003e\u003cem\u003e\u0026nbsp;\u003cstrong\u003ePerformance (before\u0026ndash;after)\u0026nbsp;\u003c/strong\u003e\u003c/em\u003e\u003c/h2\u003e\n\u003cp\u003eNo statistically significant changes were detected in live coral cover, dead coral cover, species richness, total individual abundance, fish abundance, or biomass between 2018 and 2024 across all no-take zones (paired t-test, all p \u0026gt; 0.4). While some parameters showed positive trends, all confidence intervals included zero, and effect sizes were at most moderate. The aggregate ecological changes across the four NTZs are summarized in Table 4. To comprehensively evaluate NTZ effectiveness, key ecological indicators were compared before (2018) and after (2024) protection implementation across all four sites. The aggregated and site-specific changes are presented in Table 4.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. \u0026nbsp;Summary of ecological changes across four NTZs (2018\u0026ndash;2024)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e2018 (mean)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e2024 (mean)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003eMean\u0026nbsp;\u003c/p\u003e\n \u003cp\u003edifference (\u0026Delta;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026Delta; (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003et\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 63px;\"\u003e\n \u003cp\u003eCohen\u0026rsquo;s d\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eLive coral cover\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e41.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e49.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 82px;\"\u003e\n \u003cp\u003e7.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e17.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e(-22.01, 36.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 35px;\"\u003e\n \u003cp\u003e0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eDead coral cover\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e25.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e22.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 82px;\"\u003e\n \u003cp\u003e-3.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-12.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e(-23.47, 29.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 35px;\"\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eSpecies richness\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e29.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 82px;\"\u003e\n \u003cp\u003e7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e34.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e(-17.68, 32.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 35px;\"\u003e\n \u003cp\u003e0.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eFish abundance\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(ind. ha⁻\u0026sup1;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e6270\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e5980\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 82px;\"\u003e\n \u003cp\u003e-290\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e(-2958, 3539)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 35px;\"\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 101px;\"\u003e\n \u003cp\u003eBiomass\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(kg ha⁻\u0026sup1;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e295.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e224.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 82px;\"\u003e\n \u003cp\u003e-70.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e-24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e(-135.47, 276.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 35px;\"\u003e\n \u003cp\u003e0.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: \u0026Delta;% calculated from aggregate means. Detailed site-specific data are provided in Supplementary Table S1.\u003c/p\u003e\n\u003cp\u003eAs shown in Table 4, live coral cover increased by an average of 17.5%, while fish biomass declined by 24.0%. However, none of these changes were statistically significant at the network level (*p* \u0026gt; 0.05), indicating highly variable site-specific trajectories and limited overall effectiveness of protection measures during the six-year study period. These findings suggest that there is no robust evidence of ecological recovery during the study period in these no-take zones. The ecosystem performance was influenced by water quality changes, with a 2.71% increase in sea temperature. Other parameters showed decreased salinity (2.43%), pH (0.37%), dissolved oxygen (0.35%), nitrate (12.5%), and phosphate (33.33%). Percentage changes in ecological indicators between 2018 and 2024 revealed heterogeneous recovery trajectories (Figure 8).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLive coral increased across all sites (\u0026Delta; = +10% to +75%), accompanied by dead coral reductions (\u0026Delta; = -15% to -75%). Fish abundance demonstrated divergent site responses (\u0026Delta; = -50% to +40%), with South Batee Island and Bunta Island exhibiting positive community expansion while Lhoknga and Lampuuk experienced biomass contractions (\u0026Delta; = -35% to -45%). Trophic group changes mirrored site-specific fish community trajectories, with herbivore densities ranging from a 55% decrease to a 30% increase across sites. \u0026nbsp;To investigate the mechanistic links between habitat improvement and fish community responses, Figure 9 presents pairwise correlations of the observed ecological performances.\u003c/p\u003e\n\u003cp\u003eA strong, statistically significant negative correlation was identified between the reduction in dead coral cover and the increase in fish species richness (r = -0.950; p = 0.050), indicating that substrate recovery directly facilitates ichthyofaunal diversification. A strong negative relationship exists between changes in live and dead coral cover (r = -0.867), further confirming that live coral expansion effectively displaces degraded substrate. Temporal analysis reveals a complex trajectory where increases in live coral do not immediately result in biomass gains (r = -0.801; p = 0.199). This discrepancy likely reflects a time-lag response in recovery. These findings underscore that substrate improvement is a critical precursor for biodiversity recovery and that biomass accumulation follows a delayed trajectory, necessitating long-term monitoring to capture the full extent of ecosystem benefits.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe uneven ecological responses across Aceh Besar\u0026rsquo;s NTZs highlight the complexity of marine conservation. The significant decline in biomass at South Batee Island (43%) aligns with studies showing that the effectiveness of NTZs depends on enforcement and habitat quality (Edgar et al. 2014). Comparative evidence from Tapanuli Tengah NTZs in North Sumatra demonstrates this clearly: well-enforced sites achieve 64\u0026ndash;69% hard coral cover, compared to 13\u0026ndash;39% in non-protected areas, with fish abundances 3-4 times higher. In contrast, Bunta Island\u0026apos;s biomass increase (11.9%) suggests stable habitat conditions, possibly due to lower anthropogenic pressures. The shift from herbivore-omnivore to corallivore dominance indicates declining coral health, consistent with global trends in degraded reefs (Hughes et al. 2007). This contrasts with the Anambas Islands, where adequate protection led to significant biomass recovery (Putra et al. 2021), further highlighting the critical role of enforcement. Weak enforcement, as evidenced by reported illegal fishing in Aceh Besar (Halim et al. 2019), likely exacerbates these declines. Adaptive management, including stricter patrols and habitat restoration, is critical to enhancing NTZ outcomes. Limitations include the lack of environmental data (e.g., sedimentation rates), which may influence observed trends.\u003c/p\u003e\n\u003cp\u003eThis analysis contends that future MPA establishment must embed operational commitments into design phases, rejecting the conventional approach of treating implementation as a secondary concern. This aligns with calls for shifting focus from merely expanding MPA coverage to enhancing the management effectiveness and connectivity of existing networks (White et al. 2014, 2021). Aceh Besar\u0026apos;s NTZ network provides compelling evidence that operational rigor, not legal designation alone, determines conservation outcomes. The before and after observation window captures only early establishment dynamics and proves insufficient to detect long-term recovery trajectories. This study lacked control sites and operated with limited compliance enforcement data, which constrains our ability to partition the relative contributions of protection versus external stressors. Nevertheless, these constraints illuminate critical research priorities. Three essential research directions are proposed to advance marine conservation science: (1) implement long-term adaptive monitoring frameworks spanning \u0026ge;15 years with replicated control sites to quantify recovery trajectories; (2) integrate socio-economic and ecological data to link livelihood changes with ecological outcomes mechanistically; and (3) design matched experimental comparisons between high-enforcement and low-enforcement MPA networks across Indonesia\u0026apos;s marine protected area system to isolate enforcement effects. For severely degraded sites, active restoration interventions could accelerate ecological recovery (Aja et al. 2025).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eSix-year monitoring across four no-take zones demonstrates that regulatory designation alone fails to guarantee ecosystem restoration. Indeed, the lack of significant ecological recovery suggests that these areas may never have functioned as effectively as enforced no-take zones, undermining the premise of protection itself. Uneven ecological responses across sites are revealed: live coral cover increased at three locations. In comparison, fish biomass and abundance declined at three locations, with no statistically significant changes detected across measured parameters (all p \u0026gt; 0.4). The results indicate that enforcement intensity, habitat quality, and climate stress substantially determine the effectiveness of NTZs more than legal status. These findings challenge Indonesia\u0026apos;s current marine conservation strategy, despite the country\u0026apos;s national targets to establish 30 million hectares of protected areas by 2030. The data unequivocally show that protection without robust enforcement, active habitat restoration, and climate adaptation interventions produces limited ecological returns.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics and Consent to Participate\u003c/h2\u003e\n\u003cp\u003eField surveys were conducted under Research Permit No. 500.5/2966, issued by the Department of Marine and Fisheries, Aceh Besar Regency, Indonesia. No experimental manipulation of animals or collection of endangered species was undertaken, and all surveys were conducted in accordance with applicable local and national regulations.\u003c/p\u003e\n\u003ch2\u003eCompeting interests\u003c/h2\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThis research was supported by the Indonesian Education Scholarship (BPI), managed by the Center for Higher Education Funding and Assessment (Ministry of Higher Education, Science, and Technology) and funded by the Endowment Fund for Education Agency (LPDP), Ministry of Finance, Republic of Indonesia. The funders had no role in research design, data collection, analysis, interpretation, or preparation of the manuscript.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eR.F. conceived the study, designed the methodology, conducted the investigation, performed formal analysis and data curation, wrote the original draft, prepared visualizations, and managed project administration. F.Y., Z.Z., and G.Y. contributed to conceptualization, methodology, and supervision. A.T.W. contributed to conceptualization and validation. All authors (R.F., F.Y., Z.Z., G.Y., and A.T.W.) participated in writing \u0026ndash; review \u0026amp; editing and approved the final manuscript.\u003c/p\u003e\n\u003ch2\u003eAcknowledgement\u003c/h2\u003e\n\u003cp\u003eThis work was supported by the Indonesian Education Scholarship (BPI), managed by the Center for Higher Education Funding and Assessment (Ministry of Higher Education, Science, and Technology) and funded by the Endowment Fund for Education Agency (LPDP), Ministry of Finance, Republic of Indonesia.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe datasets generated and analysed during the current study are provided as Supplementary Materials accompanying this submission. Benthic cover data (Supplementary Data S1, S2), fish community data (S3, S4), water quality time series (S5), and statistical outputs (S6) are available with the published article or from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAburto-Oropeza O, Erisman B, Galland GR, et al (2011) Large recovery of fish biomass in a no-take marine reserve. PLoS One 6:e23601. https://doi.org/10.1371/journal.pone.0023601\u003c/li\u003e\n\u003cli\u003eAdvani S, Rix L, Aherne D, et al (2015) Distance from a Fishing Community Explains Fish Abundance in a No-Take Zone with Weak Compliance. PLoS One 10:e0126098. https://doi.org/10.1371/journal.pone.0126098\u003c/li\u003e\n\u003cli\u003eAja C, Alisa G, Razak TB, et al (2025) Benthic communities on restored coral reefs confer equivalent aesthetic value to healthy reefs. 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Frontiers in Marine Science 11:1504995. https://doi.org/10.3389/fmars.2025.1504995\u003c/li\u003e\n\u003cli\u003eOhayon S, Granot I, Belmaker J (2021) A meta-analysis reveals edge effects within marine protected areas. Nature Ecology and Evolution 5:1301\u0026ndash;1308. https://doi.org/10.1038/s41559-021-01502-3\u003c/li\u003e\n\u003cli\u003ePezner AK, Courtney TA, Barkley HC, et al (2023) Increasing hypoxia on global coral reefs under ocean warming. Nature Climate Change 13:403\u0026ndash;409. https://doi.org/10.1038/s41558-023-01619-2\u003c/li\u003e\n\u003cli\u003ePutra RD, Siringiringo RM, Suryanti A, et al (2021) Impact of marine protected areas on economical important coral reef fish communities: An evaluation of the biological monitoring of coral reef fish in anambas islands, indonesia. Biodiversitas 22:4169\u0026ndash;4181. https://doi.org/10.13057/biodiv/d221006\u003c/li\u003e\n\u003cli\u003eRees M, Knott N, Neilson J, et al (2018) Accounting for habitat structural complexity improves the assessment of performance in no-take marine reserves. Biological Conservation 224:45\u0026ndash;55. https://doi.org/10.1016/j.biocon.2018.04.040\u003c/li\u003e\n\u003cli\u003eRuss GR, Alcala AC, Maypa AP, et al (2004) Marine reserve benefits local fisheries. Ecological Applications 14:597\u0026ndash;606. https://doi.org/10.1890/03-5076\u003c/li\u003e\n\u003cli\u003eSala E, Giakoumi S (2018) No-take marine reserves are the most effective protected areas in the ocean. ICES Journal of Marine Science 75:1166\u0026ndash;1168. https://doi.org/10.1093/icesjms/fsx059\u003c/li\u003e\n\u003cli\u003eSamoilys MA, Carlos G (2000) Determining methods of underwater visual census for estimating the abundance of coral reef fishes. 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Coastal Management 49:575\u0026ndash;597. https://doi.org/10.1080/08920753.2021.1967560\u003c/li\u003e\n\u003cli\u003eWhite AT, Ali\u0026ntilde;o PM, Cros A, et al (2014) Marine Protected Areas in the Coral Triangle: Progress, Issues, and Options. Coastal Management 42:87\u0026ndash;106. https://doi.org/10.1080/08920753.2014.878177\u003c/li\u003e\n\u003cli\u003eZhao L, Li T, Cong B, et al (2025) Marine Biodiversity Conservation Planning in the Indo-Pacific Convergence Zone Based on Ecological Spatial Analysis. Frontiers in Marine Science 11:1502344. https://doi.org/10.3389/fmars.2025.1502344\u003c/li\u003e\n\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":"Marine protected areas, no-take zones, ecological performance, before–and–after monitoring, Aceh Besar","lastPublishedDoi":"10.21203/rs.3.rs-8589881/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8589881/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study aimed to quantify the ecological responses of coral reef habitats and fish communities within four adjacent no-take zone (NTZs): Lhoknga, Lampuuk, Bunta Island, and South Batee Island in Aceh Besar Marine Protected Area, Indonesia, and to test whether protection implemented between 2018 and 2024 has improved ecosystem condition. Using a before-and-after comparative design, benthic cover and reef fish community structure were quantified from field surveys. Field survey data were integrated with satellite-derived water quality parameters, including sea surface temperature and nutrients. Results revealed spatial heterogeneity in recovery trajectories, with no statistically significant aggregate changes in live coral cover, fish abundance, or fish biomass across the NTZ network. South Batee Island exhibited exceptional benthic recovery but a substantial decline in fish biomass, indicating a critical disconnect between habitat improvement and resource protection, driven by weak enforcement. In contrast, only Bunta Island maintained concurrent positive trends in both habitat conditions and fish biomass. Across all sites, rising sea surface temperatures imposed chronic thermal stress. These findings challenge the assumption that regulatory designation of no-take zones guarantees ecosystem restoration in Aceh Besar, revealing instead that enforcement intensity, habitat quality, and climate stress determine NTZ effectiveness to a far greater extent than legal status alone, underscoring the urgent need to shift management focus from nominal protection to active compliance monitoring and adaptive management.\u003c/p\u003e","manuscriptTitle":"From Paper Parks to Real Protection: Ecological Performance of No-Take Zones in Aceh Besar, Indonesia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-20 14:42:07","doi":"10.21203/rs.3.rs-8589881/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":"476581fe-7f1f-45f5-a396-56c5f1f36e50","owner":[],"postedDate":"January 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-01-20T14:42:07+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-20 14:42:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8589881","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8589881","identity":"rs-8589881","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}