No-take Areas Research Articles

Reaction-diffusion for fish populations with realistic mobility

Nonlinear reaction-diffusion equations, with Fisher logistic growth and constant diffusion coefficient, have been used in fisheries research to estimate sustainable harvesting rates and critical domain sizes of no-take areas. However, constant diffusivity in a population density corresponds to standard Brownian motion of individuals, with a normal distribution for displacement over a fixed time interval. For available good data sets on mobile fish populations, the distribution is certainly not normal. The data can be fitted with a long-tailed stable Lévy distribution that results from diffusion by fractional Laplacian. Exact multidimensional solutions are developed here for realistic Fisher–Kolmogorov–Petrovski-Piscounov models with diffusion by fractional Laplacian. These can also account for a delay in the reaction term. It is then shown how to modify critical domain sizes of protected areas with Dirichlet and Robin boundary conditions for populations.

Shortened food chain length in a fished versus unfished coral reef.

Direct exploitation through fishing is driving dramatic declines of wildlife populations in ocean environments, particularly for predatory and large-bodied taxa. Despite wide recognition of this pattern and well-established consequences of such trophic downgrading on ecosystem function, there have been few empirical studies examining the effects of fishing on whole system trophic architecture. Understanding these kinds of structural impacts is especially important in coral reef ecosystems-often heavily fished and facing multiple stressors. Given the often high dietary flexibility and numerous functional redundancies in diverse ecosystems such as coral reefs, it is important to establish whether web architecture is strongly impacted by fishing pressure or whether it might be resilient, at least to moderate-intensity pressure. To examine this question, we used a combination of bulk and compound-specific stable isotope analyses measured across a range of predatory and low-trophic-level consumers between two coral reef ecosystems that differed with respect to fishing pressure but otherwise remained largely similar. We found that even in a high-diversity system with relatively modest fishing pressure, there were strong reductions in the trophic position (TP) of the three highest TP consumers examined in the fished system but no effects on the TP of lower-level consumers. We saw no evidence that this shortening of the affected food webs was being driven by changes in basal resource consumption, for example, through changes in the spatial location of foraging by consumers. Instead, this likely reflected internal changes in food web architecture, suggesting that even in diverse systems and with relatively modest pressure, human harvest causes significant compressions in food chain length. This observed shortening of these food webs may have many important emergent ecological consequences for the functioning of ecosystems impacted by fishing or hunting. Such important structural shifts may be widespread but unnoticed by traditional surveys. This insight may also be useful for applied ecosystem managers grappling with choices about the relative importance of protection for remote and pristine areas and the value of strict no-take areas to protect not just the raw constituents of systems affected by fishing and hunting but also the health and functionality of whole systems.

Marine protected areas can be useful but are not a silver bullet for kelp conservation.

Kelp forests are among the most valuable ecosystems on Earth, but they are increasingly being degraded and lost due to a range of human-related stressors, leading to recent calls for their improved management and conservation. One of the primary tools to conserve marine species and biodiversity is the establishment of marine protected areas (MPAs). International commitments to protect 30% of the world's ecosystems are gaining momentum, offering a promising avenue to secure kelp forests into the Anthropocene. However, a clear understanding of the efficacy of MPAs for conserving kelp forests in a changing ocean is lacking. In this perspective, we question whether strengthened global protection will create meaningful conservation outcomes for kelp forests. We explore the benefits of MPAs for kelp conservation under a suite of different stressors, focusing on empirical evidence from protected kelp forests. We show that MPAs can be effective against some drivers of kelp loss (e.g., overgrazing, kelp harvesting), particularly when they are maintained in the long-term and enforced as no-take areas. There is also some evidence that MPAs can reduce impacts of climate change through building resilience in multi-stressor situations. However, MPAs also often fail to provide protection against ocean warming, marine heatwaves, coastal darkening, and pollution, which have emerged as dominant drivers of kelp forest loss globally. Although well-enforced MPAs should remain an important tool to protect kelp forests, successful kelp conservation will require implementing an additional suite of management solutions that target these accelerating threats.

Application of the Method Evaluation and Risk Assessment Tool for a Small-Scale Grouper Fishery in Indonesia

Management strategy evaluation using the Method Evaluation and Risk Assessment (MERA) platform was used to evaluate management procedures (MPs) for improving the management of the leopard coral grouper (Plectropomus leopardus) fishery in Saleh Bay, Indonesia. This grouper is a valuable species currently under high fishing pressure. It is targeted by small-scale fisheries using a wide range of fishing methods; hence, management recommendations are needed to ensure sustainability. A suite of MPs for data-limited conditions were evaluated for their ability to achieve limit and target biomass reference points (B/BMSY = 0.5 and B/BMSY = 1, respectively), while maintaining a target yield of at least 0.5 MSY. The simulation results suggest that the currently implemented harvest control rules (HCRs) in Saleh Bay (size limit and spatial closure) may not be effective in achieving the management objective to attain the target biomass reference point due to relatively low compliance with the size limit regulation (320 mm total length) and the very small proportion of existing MPA no-take areas (~2.2%). This study recommends that the fisheries management authority explores the feasibility of implementing the total allowable catch (TAC) and seasonal closure in addition to the existing fishing regulations for P. leopardus in Saleh Bay.

Movement patterns of Natal seacatfish Galeichthys troworum (Ariidae) tagged in the Pondoland Marine Protected Area, Eastern Cape, South Africa

A tag-recapture study was undertaken on the Natal seacatfish Galeichthys troworum in the Pondoland Marine Protected Area (PMPA) on the east coast of South Africa. A total of 473 fish were tagged over a period of 8 years, and 136 individuals (28.8%) were recaptured over a period of 16 years, some of them on multiple occasions. Most recaptures (82%) were caught within 200 m of their release site, with movements ranging between 0 and 617 m, and time-at-liberty ranging between 0 and 3 407 days (9.3 years). Data analysis showed that all recaptured fish remained in relatively small home ranges (of ∼360 m linear distance) and none of them abandoned their home range and moved out of the 2-km2 sampling blocks. While the no-take area of the PMPA provided effective protection for these fish, their relative abundance was similar in an adjacent exploited area. This is likely because G. troworum is not a desired linefish species, with most individuals caught being released, coupled with high post-release survival.

The future of the South Georgia and South Sandwich Islands marine protected area in a changing environment: The choice between industrial fisheries, or ecosystem protection

South Georgia and the South Sandwich Islands (SGSSI) comprise an Overseas Territory of the UK. For over two centuries, the islands and surrounding waters were subject to serial over-exploitation of commercially valuable marine species. First seals, then whales, and later some species of fish were harvested to virtual economic extinction. Today, exploitation is strictly regulated: through the multilateral Convention on the Conservation of Antarctic Marine Living Resources; through the commercial whaling moratorium of the International Whaling Commission; and now, increasingly, through local sovereign government legislation. Commercial fisheries still operate for three species of fish and one species of crustacean, Antarctic krill. Here, I consider aspects of these fisheries, to help inform the current review of the SGSSI Marine Protected Area (MPA), highlighting how future management must take into account important ongoing changes in this biodiverse ecosystem. Two issues are of paramount importance: ongoing recovery of baleen whale species; and climate change. Both increase uncertainty for fisheries managers, so that considerations about their implications must now be directly included into the management of harvested and dependent species. With the recovery of some previously exploited species, and ongoing recovery of others, the MPA could now be managed with additional ecologically-appropriate large no-take areas, commensurate with increasing levels of ocean protection advocated for by a growing number of scientists and governments. Spatial protection reflecting the habitat use of baleen whales and their prey, krill, would, through umbrella protection, also protect other biodiversity integral to the operation of the marine ecosystem.

Assessing benthic reef assemblages: A comparison between no-take artificial reefs and partially protected natural reefs

The marine protected area (MPA) of the Espiritu Santo Archipelago (ESA; Gulf of California), is exposed to a high level of anthropogenic disturbances, consequently, the local authorities have deployed artificial reefs (shipwrecks) in the ESA area to increase fishing refuges, breeding sites, and tourist attractions. To explore the potential contribution of these artificial reefs as a conservation tool, we compared their benthic community structures (i.e. diversity and live cover categories) to those of the natural reefs. Our results indicate a higher abundance of mollusks on the artificial reefs compared to the natural reefs; a higher echinoderm abundance on the natural reefs; and a very similar species richness of hexacorals between the natural and artificial reefs, with 10 and 9 species recorded respectively. The natural reefs hosted a four-fold higher live cover of hexacorals than the artificial reefs, while the artificial reefs had a higher number of octocoral species, 8 versus 5 on the natural reefs. In addition, the artificial reefs had a 4.6 fold higher octocoral cover than the natural reefs. Overall findings indicate that the benthic community assemblages significantly differ between the natural and artificial reefs, which may be related to their location, structural composition, material, and morphology. These results suggest that shipwrecks have the potential to enhance local reef diversity by increasing the cover and abundance of certain benthic-associated species. Although the shipwrecks do not function as surrogate habitats for the adjacent natural rocky reefs, as no-take areas they provide suitable refuges for several target species (e.g. black coral and mollusks).

Drivers of temporal variation in benthic cover and coral health of an oceanic intertidal reef in Southwestern Atlantic

Intertidal environments and shallow reefs are subject to natural disturbances and impacts by humans that influence their dynamics and therefore their conservation. These environments are among the most subject to anthropogenic impacts worldwide, ranging from global warming to local pollution and disordered tourism. Fernando de Noronha Marine National Park is an important Marine Protected Area that covers marine habitats up to 50 m deep of an oceanic archipelago off North East Brazil. It is a no-take area, so the main potential impacts in intertidal and shallow environments there are related to tourism, pollution and climate change. One of the chief tourist attractions in this Park is a tide pool where snorkelers can dive under a series of regulations. We monitored corals and benthic organisms in this tide pool for two years and evaluated their response to different disturbances: burial by sand, temperature anomalies, and tourism. We observed high temporal variability in the benthic cover in the Atalaia pool, with an important role of the sand being naturally brought by waves coming from the southeast to south-southeast direction on a seasonal basis. Despite the highly variable environment of this pool leading to periodic visual coral cover decrease when sand accumulated, coral health was not significantly affected neither by burial nor by the number of visitors accessing the pool. However, sea temperature anomaly played a role, being the main environmental driver affecting coral health, leading to increased paleness, bleaching and unhealthy purple/pink color and causing changes on the associated symbionts. Regardless of the local scope of this monitoring, this is an interesting study case to be used by other marine parks, explicitly showing how biological monitoring can aid the evaluation and potential adjustments to management strategies.

A pan-Baltic assessment of temporal trends in coastal pike populations

The northern pike (Esox lucius) is an iconic predatory fish species of significant recreational value and ecological role in the Baltic Sea. Some earlier studies indicate local declines of pike in the region, but a thorough spatial evaluation of regional population trends of pike in the Baltic Sea is lacking. In this study, we collate data from 59 unique time-series from fisheries landings and fishery-independent monitoring programs to address temporal trends in pike populations since the mid-2000′s in eight countries surrounding the Baltic Sea. In a common analysis considering all time-series in concert, we found indications of an overall regional temporal decline of pike in the Baltic Sea, but trends differed among countries. Individual negative trends in time-series were moreover found in several regions of the Baltic Sea, but predominantly so in the central and southern parts, while positive trends were only found in Estonia and northern Finland. The mix of data used in this study is inherently noisy and to some extent of uncertain quality, but as a result of the overall negative trends, together with the socioeconomic and ecological importance of pike in coastal areas of the Baltic Sea, we suggest that actions should be taken to protect and restore pike populations. Management measures should be performed in combination with improved fishery-independent monitoring programs to provide data of better quality and development of citizen-science approaches as a data source for population estimates. Possible measures that could strengthen pike populations include harvest regulations (including size limits, no-take areas and spawning closures), habitat protection and restoration, and an ecosystem-based approach to management considering also the impact of natural predators.

Movement patterns and growth rate of Scotsman Polysteganus praeorbitalis (Sparidae) tagged in the Pondoland Marine Protected Area, Eastern Cape, South Africa

A tag-recapture study was undertaken on Polysteganus praeorbitalis in the Pondoland Marine Protected Area (PMPA) on the east coast of South Africa. A total of 1 042 fish were tagged over a period of 16 years and 255 individuals (24.5%) were recaptured, some of them on multiple occasions. Data analysis showed that 84.7% of recaptured fish remained in relatively small home ranges (-750 m linear distance), while 13.3% abandoned their home ranges and undertook unidirectional movements (of 21-1 211 km) along the KwaZulu-Natal coast in a north-easterly direction, most likely to spawn. While the no-take area of the PMPA provides effective protection for resident fish, the export of adult P. praearbitalis provides strong evidence of the benefits that no-take MPAs can offer to adjacent fisheries. Based on the tag-recapture length data, the growth rate was found to be relatively slow, averaging 46 mm y-1. This growth rate was similar to that determined by a study of ageing using sectioned otoliths. Reliable tag-recapture data can thus be used to provide a valuable means of validating growth rates determined by other methods.

Effects of fishing on the trophic structure of carnivorous fish assemblages from shallow rocky bottoms of the Mediterranean Sea and the temperate Atlantic Ocean

Abstract Here, we assess whether fishery exploitation affects the trophic structure of carnivorous fish. We censused fish and analysed the stable isotope ratios of C and N of species targeted by fishermen in areas open to fishing and marine protected areas (MPAs) in the Mediterranean Sea and the north-eastern Atlantic Ocean. Results demonstrated a major impact of fishing on the biomass and size structure of nektobenthic carnivorous fish. However, those changes did not modify the diversity of the trophic resources used by the assemblage, the pattern of resource partitioning between species, or the degree of trophic redundancy. These results add to recent evidence suggesting that MPAs implemented in fished seascapes may fail to restore the original structure of the food webs that once existed in pre-fished ecosystems because regional decimation and extinction of highly mobile predators prevent recovering the original diversity of predators at local scales, even in no-take areas. If so, more strict local fishing regulations are unlikely to restore the original diversity of high trophic level carnivores and restoration goals should be reframed in terms of an objective that is less unrealistic than restoring the pre-fished condition while still recovering aspects of the historical trophic structure.

Assessing the effects of no-take zones in a marine protected area spanning two ecoregions and rock substrate types

This study assessed the effectiveness of no-take areas in the Table Mountain National Park MPA in protecting the biodiversity of intertidal rocky shores from impacts of harvesting. Surveys were conducted in areas of controlled harvesting and in no-take areas to compare the densities and sizes of exploited species and the community composition between shores experiencing these two levels of protection, in two ecoregions and on two types of rock substrate. Clear patterns emerged. Firstly, no-take areas had significantly greater densities of the exploited limpets Cymbula granatina, C. oculus and Scutellastra argenvillei, particularly on sandstone shores, relative to their abundance in harvested areas. Conversely, densities of the rarely harvested limpets S. cochlear, S. longicosta and S. granularis did not differ in any manner consistent with protection levels. Secondly, C. granatina and S. argenvillei were significantly larger in no-take areas, although C. oculus displayed the opposite pattern. None of the rarely harvested limpets showed consistent differences in sizes between protection levels. Thirdly, community composition differed between protection levels, particularly on sandstone shores and in the lower intertidal zones where limpets are common. No-take areas were distinguished by greater abundances of harvested limpets and mussels, while harvested areas were dominated by ephemeral and corticated algae, which flourished under reduced grazing pressure by limpets. Our study provides congruent evidence that no-take areas within this MPA are effective in maintaining a natural rocky-shore community composition, and natural densities and size structures of exploited species, testifying to the management success of no-take areas in the Table Mountain National Park, especially on sandstone shores of the Southern Benguela, where densities of harvested species are high, and harvesting is concentrated.

Rapid re-establishment of top-down control at a no-take artificial reef

Establishment of artificial reefs and no-take areas are management measures available for restoring deteriorated marine ecosystems, compensating for habitat loss and strengthening harvested populations. Following the establishment of no-take artificial reefs in western Sweden to compensate for hard bottoms lost to a shipping lane, we detected rapid positive effects on crustaceans and demersal fish compared to fished reference areas. The relative abundance and size structure of European lobster (Homarus gammarus) increased strongly in the no-take area indicating more than doubled and tripled egg production in 5 and 10 years, respectively. For benthic fish and crustacean communities, the abundances of gadoids and wrasses increased and the abundances of small decapod crustaceans decreased in the no-take area, likely indicating cascading effects of increased predation. The study demonstrates that relatively small no-take areas, enhanced by artificial reefs, can rapidly invigorate populations of lobster and fish that in turn may re-initiate local top-down control.

Among-individual variation in white seabream (Diplodus sargus) spatial behaviour and protection in a coastal no-take area

Abstract Marine protected areas (MPAs), and specially no-take areas (NTAs), play an important role in protecting target populations from fisheries. When developing spatial conservation and management tools, the design has mainly focused on population-level measures of fish home ranges, spawning and feeding areas, and migration routes. Intraspecific differences in fish behaviour, however, are often not accounted for, even though they could influence the level of realized protection. In this study, we investigated the intraspecific variation in spatial behaviour of a harvested fish, Diplodus sargus, and how it impacts the degree of protection granted by a NTA in the south of Portugal. We identified four behavioural types according to their spatial behaviour: residents, commuters, seasonal visitors, and single users. Time at risk (i.e. outside the NTA) greatly varied among the four groups, but also over the year for the seasonal and the single users. Our study shows how acoustic telemetry can assist spatial conservation and fisheries management and provides novel insight regarding the role of individual variation in behaviour to understand protection granted by MPAs to harvested species. It also suggests that incorporating such information into all stages of MPA design and implementation can result in increased resilience of the protected populations.

Movements of Hatchery-Reared Dusky Groupers Released in a Northeast Atlantic Coastal Marine Protected Area

No-take areas are key instruments to promote the effectiveness of Marine Protected Areas (MPAs), particularly concerning the protection of endangered species such as the dusky grouper (Epinephelus marginatus). However, despite the establishment of no-take areas and the prohibition of catching this species in a southwestern Portuguese MPA (SACVMP—‘Sudoeste Alentejano’ and ‘Costa Vicentina’ Marine Park) since 2011, there is still no evidence of population recovery. By using acoustic biotelemetry, this work aimed to evaluate the feasibility of restocking hatchery-reared adult dusky groupers in two no-take areas within the SACVMP. In 2019 and 2021, thirty groupers were tagged with acoustic transmitters and the site attachment and movements of the groupers were assessed in the releasing sites (no-take areas). None of the tagged fish settled down in either of the areas, leaving the no-take areas mainly at dusk and night. Some individuals displayed extended movements of more than a hundred kilometers along the Portuguese coast which was rarely reported for this species. At least in some coastal stretches, those movements were performed close to the shore, which may evidence the importance of coastal MPAs to protect and promote the connectivity of species more associated with rocky reef habitats. Following studies should focus on the conditions that promote site attachment and fidelity by hatchery-reared dusky groupers so that future large-scale restocking programs can be successful in MPAs with appropriate habitats.

Effects on faunistic composition and population characteristics of decapod crustaceans after the implementation of a fisheries no-take area in the NW Mediterranean

The establishment of fisheries no-take areas is considered an effective method for the recovery of populations of exploited species and their habitats. Here we study the faunistic composition of decapod crustaceans after the implementation of a no-take area in the Gulf of Roses (NW Mediterranean) in 2014. We studied the occurrence (presence/absence) and density of all decapod crustaceans sampled by trawling inside and outside a no-take area from March 2015 to July 2018. Sizes were assessed for all common species. A total of 33 species of decapod crustaceans were recorded. Four species showed significantly higher occurrences in the no-take area and three in the open area, while significantly higher densities were found for four species in the no-take area and three in the open area. Multivariate analysis showed marked differences between the no-take area and the open area, while also showing that the two areas were undergoing a divergence. The comparison of sizes between the two zones showed species-specific patterns that in many cases showed that both the smallest and the largest individuals were present in the no-take area, suggesting that the closing of this area would be important for recruitment and juvenile development, as well as for protection of large-sized individuals. All evidence indicates that the establishment of the no-take area has led to an improvement in biodiversity and species population descriptors.

Multidecadal monitoring highlighted long-term stability of protected assemblages within a Mediterranean marine reserve

Marine Protected Areas (MPAs) are at the core of management and conservation plans aimed at counteracting the ongoing widespread degradation of marine ecosystems. Although the outcomes of protection in enhancing marine biodiversity and restoring populations of exploited species are widely recognized, the putative effect of MPAs in increasing the resilience of marine communities and ecosystems is still underexplored. In this study, long-term data from a no-take area of a Mediterranean MPA and unprotected locations were used to investigate the effects of full protection on the temporal stability of sessile assemblages on shallow subtidal rocky reefs. Results highlighted that assemblages within the no-take area exhibited a more consistent structure over 20 years of study, whereas a significantly larger temporal variability characterized assemblages at the unprotected locations. Reduced levels of human pressure and stabilizing processes related to the re-establishment of the integrity of trophic networks within the MPA could underlie the observed patterns. Assessing whether MPAs may improve the ability of marine communities to absorb disturbance, from local to large scale sources, is essential to ascertain their contribution to future adaptive conservation strategies in the face of global change. This study provided evidence that MPAs, if well managed, can represent an effective tool to smooth fluctuations in the structure of marine communities, thus potentially reducing their vulnerability to natural and human-driven environmental changes.

Emerging marine protected areas of eastern Indonesia: Coral reef trends and priorities for management

Indonesian coral reefs are under pressure from illegal, unregulated and unreported fishing, the use of destructive fishing practices, land-based pollution, coastal development and climate change. Marine protected areas (MPAs) are necessary to allow habitat recovery and fish stock replenishment. Through the United States Agency for International Development Sustainable Ecosystems Advanced Project (2016–2021), Indonesia worked to improve fisheries productivity and sustainable livelihoods within the three provinces of Maluku, North Maluku and West Papua, where 13 new coral reef MPAs were designed for multiple use, with a zoning system to support biodiversity conservation and sustainable fisheries. At the time of writing in mid-2021, regulations to prohibit fishing within the no-take areas (NTAs) were not yet implemented. This paper presents baseline and trends in percent coral cover and reef fish density and biomass in the MPAs. In 2020, overall coral cover had increased from 42% to 45% across all MPAs. The average target fish biomass across all NTAs had declined from 1709 ( ± 176 SE) kg per hectare in 2017 to 884 ( ± 76 SE) kg per hectare in 2020, representing a significant decline of about 48%. Large and significant declines in many target fish families across multiple MPAs are reflective of unsustainable levels of exploitation. It is evident that management plans need to be implemented with adequate enforcement and stakeholder engagement to stem the decline of target species and to secure livelihoods for local fishing communities.

Spatially explicit food web modelling to consider fisheries impacts and ecosystem representation within Marine Protected Areas on the Kerguelen Plateau

Abstract The Kerguelen Plateau in the Indian sector of the Southern Ocean is a highly dynamic region for Southern Ocean ecosystems and an important region for the Patagonian toothfish fishery. Fished regions overlap with foraging regions for predators; however, no study has explored the spatial impacts of fishing on ecosystem dynamics. We developed two spatially explicit ecosystem models to (i) explore the spatial effects of fishing on the Patagonian toothfish and the ecosystem in scenarios with and without fishing; and (ii) use modelled distributions to compare ecosystem representation in Marine Protected Areas (MPAs) with existing studies. Consistent with other studies, we found decreases in Patagonian toothfish biomass in scenarios with fishing activity. In contrast, we found no spatial fishing impacts on ecosystem interactions. A majority of functional group distributions were positively correlated with phytoplankton and well distributed within no-take areas. This could indicate a high level of representation of species in MPAs. Our study provides valuable insights into spatial ecosystem dynamics on the Kerguelen Plateau; however, our interpretations were limited and more research is needed to disentangle the natural variation from fishing impacts and further explore spatio-temporal changes in phytoplankton on the ecosystem.

Depth and benthic habitat influence shallow and mesophotic predatory fishes on a remote, high-latitude coral reef

Predatory fishes on coral reefs continue to decline globally despite playing key roles in ecosystem functioning. Remote atolls and platform reefs provide potential refugia for predator populations, but quantitative information on their spatial distribution is required to establish accurate baselines for ongoing monitoring and conservation management. Current knowledge of predatory fish populations has been derived from targeted shallow diver-based surveys (<15 m). However, the spatial distribution and extent of predatory fishes on outer mesophotic shelf environments has remained under described. Middleton Reef is a remote, high-latitude, oceanic platform reef that is located within a no-take area in the Lord Howe Marine Park off eastern Australia. Here we used baited remote underwater stereo video to sample predatory fishes across lagoon and outer shelf habitats from depths 0-100 m, extending knowledge on use of mesophotic depths and habitats. Many predatory fish demonstrated clear depth and habitat associations over this depth range. Carcharhinid sharks and Carangid fishes were the most abundant predators sampled on Middleton Reef, with five predatory fishes accounting for over 90% of the predator fish biomass. Notably, Galapagos shark (Carcharhinus galapagensis) and the protected black rockcod (Epinephelus daemelii) dominated the predator fish assemblage. A higher richness of predator fish species was sampled on reef areas north and south of the lagoon. The more exposed southern aspect of the reef supported a different suite of predator fish across mesophotic habitats relative to the assemblage recorded in the north and lagoonal habitats, a pattern potentially driven by differences in hard coral cover. Biomass of predatory fishes in the more sheltered north habitats was twice that of other areas, predominantly driven by high abundances of Galapagos shark. This work adds to the growing body of literature highlighting the conservation value of isolated oceanic reefs and the need to ensure that lagoon, shallow and mesophotic habitats in these systems are adequately protected, as they support vulnerable ecologically and economically important predator fish assemblages.