No-take Marine Protected Areas Research Articles

Study on the relationship between economic input growth in Marine protected areas and environmental governance in the North Pacific Coast of Costa Rica: Based on reef fish assemblages

Reef fish communities under fishing pressure often experience reduced biomass, abundance, and altered size structure. The establishment of marine protected areas (MPAs) can help mitigate these declines. However, the success of MPAs, especially in developing countries with financial and socioeconomic challenges, largely hinges on effective enforcement. This study utilized underwater visual surveys (UVS) and baited remote underwater video stations (BRUVS) to evaluate population density, size distribution, and biomass of both economically valuable (e.g., target and ornamental species) and ecologically important (e.g., small/large predators and herbivores) fish groups within and outside a no-take MPA on the northern Pacific coast of Costa Rica.The results indicated that protective measures did not significantly affect the biomass of economically valuable fish species. However, there were notable differences in fish abundance and size distribution between no-take zones (where fishing is prohibited) and open-fishing zones. This suggests that, despite potential illegal fishing activities within the MPA, certain fish community components benefit from the protective measures.Specifically, herbivores and ornamental fish, which are often targeted by artisanal compressor fishing and the aquarium trade, exhibited higher biomass and abundance levels within the MPA. Additionally, significant shark species such as Galeocerdo cuvier, Carcharhinus leucas, and Carcharhinus limbatus were exclusively found within the MPA.The study also highlighted the crucial role of habitat quality, particularly high coral cover, in enhancing the biomass of ornamental fish.This research contributes to the growing body of evidence that MPAs, even with limited enforcement, consistently offer ecological benefits for reef fish communities

Chemical contamination affecting filter-feeding bivalves in no-take marine protected areas from Brazil

Marine protected areas (MPAs) are zones geographically delimited under pre-defined management goals, seeking to reduce anthropogenic threats to biodiversity. Despite this, in recent years reports of MPAs affected by chemical contamination has grown. Therefore, this study addresses this critical issue assessing legacy and current chemical contamination in filter-feeder bivalves obtained in very restrictive no-take MPAs from Brazil. The detected pollutants encompass polycyclic aromatic hydrocarbons (PAHs), linear alkylbenzenes (LABs), and persistent organic pollutants (POPs) like dichlorodiphenyltrichloroethane (DDTs) and polychlorinated biphenyls (PCBs). Despite protective measures, bivalves from nine MPAs exhibited high LABs (13.2–1139.0 ng g−1) and DDTs levels (0.1–62.3 ng g−1). PAHs were present in low concentrations (3.1–29.03 ng g−1), as PCBs (0.7–6.4 ng g−1), hexachlorobenzene (0.1–0.2 ng g−1), and Mirex (0.1–0.3 ng g−1). Regardless of the sentinel species, MPAs and management categories, similar accumulation patterns were observed for LABs, DDTs, PAHs, and PCBs. Based on the limits proposed by Oslo Paris Commission, the measured levels of PAHs, PCBs and were below the environmental assessment criteria. Such findings indicate the no biological effects are expected to occur. However, they are higher considering background conditions typically measured in remote or pristine areas and potential simultaneous exposure. Such findings indicate an influence of anthropogenic sources, emphasizing the urgency for monitoring programs guiding strategic management efforts to safeguard these areas.

The illegal exploitation of threatened manta and devil rays in the Chagos Archipelago, one of the world’s largest no-take MPAs

Illegal fishing is a concern within marine protected areas (MPA) worldwide, particularly for threatened species such as manta and devil rays (mobulids). However, due to the lack of taxonomic knowledge of enforcement personnel, illegal fishing catch records relating to mobulids can be limited. Here, an examination of illegal catch photographs from local enforcement authorities of the Chagos Archipelago’s vast no-take MPA revealed approximately 79 individual mobulids from just seven vessels, equating to an estimated 20 tonnes. This is likely a vast underestimation due to the limited detection of illegal fishing activity and species-specific reporting. If catches of this magnitude are commonplace within the MPA, they are likely having a detrimental effect on local mobulid populations. Accurate and consistent catch data recording and reporting are crucial to fulfil mobulid conservation responsibilities, as is comprehensive research on the movement ecology and habitat use dynamics of all mobulid species in the region.

Climate change reduces long-term population benefits from no-take marine protected areas through selective pressures on species movement.

Marine protected areas (MPAs) are important conservation tools that confer ecosystem benefits by removing fishing within their borders to allow stocks to rebuild. Fishing mortality outside a traditionally fixed MPA can exert selective pressure for low movement alleles, resulting in enhanced protection. While evolving to move less may be useful for conservation presently, it could be detrimental in the face of climate change for species that need to move to track their thermal optimum. Here, we build a spatially explicit simulation model to assess the impact of movement evolution in and around static MPAs resulting from both fishing mortality and temperature-dependent natural mortality on conservation benefits across five climate scenarios: (i) linear mean temperature shift, (ii) El Niño/La Niña conditions, (iii) heat waves, (iv) heatwaves with a mean temperature shift, and (v) no climate change. While movement evolution allows populations within MPAs to survive longer, we find that over time, climate change degrades the benefits by selecting for higher movement genotypes. Resulting population declines within MPAs are faster than expected based on climate mortality alone, even within the largest MPAs. Our findings suggest that while static MPAs may conserve species for a time, other strategies, such as dynamic MPA networks or assisted migration, may also be required to effectively incorporate climate change into conservation planning.

A diverse portfolio of marine protected areas can better advance global conservation and equity

Marine protected areas (MPAs) are widely used for ocean conservation, yet the relative impacts of various types of MPAs are poorly understood. We estimated impacts on fish biomass from no-take and multiple-use (fished) MPAs, employing a rigorous matched counterfactual design with a global dataset of >14,000 surveys in and around 216 MPAs. Both no-take and multiple-use MPAs generated positive conservation outcomes relative to no protection (58.2% and 12.6% fish biomass increases, respectively), with smaller estimated differences between the two MPA types when controlling for additional confounding factors (8.3% increase). Relative performance depended on context and management: no-take MPAs performed better in areas of high human pressure but similar to multiple-use in remote locations. Multiple-use MPA performance was low in high-pressure areas but improved significantly with better management, producing similar outcomes to no-take MPAs when adequately staffed and appropriate use regulations were applied. For priority conservation areas where no-take restrictions are not possible or ethical, our findings show that a portfolio of well-designed and well-managed multiple-use MPAs represents a viable and potentially equitable pathway to advance local and global conservation.

Co-management of marine protected areas: Challenges and lessons from the most urbanized coastline of the South Western Atlantic

Marine Protected Areas (MPAs) are powerful instruments to conserve biodiversity and ecosystems, if supported by an effective management structure. In Brazil, no-take and multiple-use MPAs have advisory councils that allow co-management as an important strategy to deal with conservation challenges, mainly in urbanized coastal areas. However, the profile of members and their perceptions regarding advisory council challenges remain poorly known. Here, we assessed the advisory management councils of the largest network of MPAs in the South Western Atlantic, situated next to one of the largest metropolitan areas in the world. Seven MPA advisory councils were initially characterized through consultation with the MPA managers, followed by interviews with each advisory council member. We found that advisory council members were mostly agents of the local government, university scientists, members of local associations, and employees of non-governmental organizations. Compared with no-take MPAs, multiple-use MPAs tended to have greater diversity of member profiles in terms of institutional affiliation, gender, training level and age group. Although the majority of respondents considered the advisory councils an effective management tool, almost 30% of the interviewees did not recognize this mechanism as efficient, and the perceived capacity for advisory councils to respond to challenges was lower in no-take MPAs. This perception was attributed to a lack of complete actor inclusivity and the low decision-making power of advisory councils. There was a general agreement that no-take MPA advisory councils in particular are not achieving their sustainability goals and have progressed less than multiple-use MPAs in terms of co-management. To overcome this, we provide a series of recommendations to improve stakeholder participation and co-management of MPA operation.

Forty Years of No-Take Protection Preserves Local Fish Diversity in a Small Urban Marine Protected Area

Small no-take marine protected areas (MPAs) in urban settings can fail to adequately protect biodiversity due to the combined effects of illegal fishing and species emigrating outside the protected area boundaries. Further assessment of the effectiveness of these areas is needed to provide insights into how they can best be managed to generate conservation benefits. The Fly Point no-take MPA in Port Stephens, New South Wales, Australia, was used as a case study, with the objective of examining whether a small urban no-take MPA can produce conservation benefits, despite the handicaps imposed by its size and location. Diver-based underwater visual census data, recording fish species and abundances, was obtained from 434 surveys conducted in Port Stephens (2009–2022) at three sites within the Fly Point no-take MPA and at three surrounding sites open to fishing. These data were analysed using permutational multivariate analysis of variance to determine whether no-take protection significantly benefited fish species richness and diversity. We found significantly higher species richness for sites in the no-take MPA than in surrounding areas and significant differences in assemblages between no-take and fished areas, driven in part by greater abundances of two fishery-targeted species in the no-take MPA (Acanthopagrus australis and Scorpis lineolata). Generally, fish diversity was also significantly higher for sites within the no-take MPA, although diversity was also high in fished sites adjacent to the no-take MPA. Study results demonstrate that small urban no-take MPAs can provide conservation benefits, especially when these areas have been protected for more than a decade and where high visibility and local stewardship enable adequate enforcement of no-take restrictions. Consequently, planning for MPAs in urban areas should endeavour to ensure high levels of public support and, ideally, should situate MPAs in highly visible locations, in order to maximise their conservation outcomes.

Optimizing efficiency and resilience of no-take marine protected areas for fish conservation under climate change along the coastlines of China Seas.

Climate change is one of the major threats to coastal fish biodiversity, and optimization of no-take marine protected areas (MPAs) is imminent. We predicted fish redistribution under climate change in coastal China Seas with joint species distribution modeling and prioritized areas for conservation with Zonation, for which we used core area zonation (CAZ) and additive benefit function (ABF). Based on our results, we devised an expansion plan of no-take MPAs. Under climate change, fish were redistributed northward along the coast. These redistributions were segmented by the Yangtze River estuary and its adjacent waters, indicating a possible biogeographical barrier. Under CAZ and ABF, significantly more fish habitat was conserved than under random prioritization (p<0.001, Cohen's d=-0.36 and -0.62, respectively). The ABF better represented areas with higher species richness, whereas CAZ better represented core habitats for species with narrow distributions. Without accounting for species redistribution, the expanded MPAs were mainly distributed in the northwest of the South China Sea, the East China Sea, the north of the Yellow Sea, and the west of the Bohai Sea. When accounting for species redistribution, the proposed MPAs were mainly distributed in the north of the Bohai Sea and southwest of the Yellow Sea, corresponding to the northern species redistributions. These MPAs conserved less habitat for fishes at present but protected more and better quality habitat for fishes in 2050 and 2100 than those MPAs that did not account for species redistribution, indicating improved fish conservation under climate change. Incorporating species redistribution and trade-offs between areas with high species richness and areas that contain habitats for rare species are suggested to address coastal fish conservation under climate change. This work provides valuable information for fish conservation and is a precursor to systematic conservation planning along the coastlines of China Seas.

Identifying suitable indicators to measure ecological condition of rocky reef ecosystems in South Africa

Baseline data for reference conditions are needed to determine the impacts of human pressures on the structure and functioning of marine ecosystems. However, baseline data are seldom available, and a comprehensive understanding of what good ecological condition is or how to measure it is often lacking. In the absence of true baselines, well established and effective marine protected areas (MPAs) can be used to approximate reference conditions. Thus, the aim of this study was to use effective no-take MPAs to identify suitable indicators that can be used for condition assessments of rocky reefs in South Africa. To achieve this, we tested the response of two types of metrics (compositional and size-based), using in situ fish and benthic community data, to three levels of human pressures in two ecoregions in South Africa. Results showed that traditionally-used structural metrics, such as total abundance or species richness, were less responsive than size-based metrics, including total biomass, average length and proportion of mature fish. Rocky reef ecosystems exposed to low anthropogenic pressure were characterised by a higher biomass, average length and proportion of mature and large (>30 cm) fish than reefs with moderate and high pressures. Benthic communities appeared more resilient than fish communities to the typical human pressures in the study region. Overall, the greatest effect of pressure was observed in the heavily impacted sub-tropical Natal Shelf Ecoregion, while rocky reefs in the warm-temperate Agulhas Shelf Ecoregion appeared to be in better condition than expected. This study identified assemblage patterns and indicators that appeared responsive and sensitive to different levels of human pressure, which can be used to infer good and poor ecological condition of rocky reef ecosystems. These results indicate which species (e.g., target species) and traits (e.g., size) are most vulnerable to local human pressures and will be suitable for condition assessments.

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems.

Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014-2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no-take state marine reserves, and 76 partial-take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no-take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat-wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem-wide consequences resulting from acute climate-driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.

Consistent edge effect patterns revealed using continuous surveys across an Eastern Mediterranean no-take marine protected area

AbstractBecause marine protected areas (MPAs) are not equally effective across their areas, monitoring should progress from dichotomic (within vs. outside) to a finer spatial resolution. Here, we examine the effect of an Eastern Mediterranean no-take MPA on fishes across the MPA and into fished areas, using three methods: underwater visual censuses, acoustic surveys, and towed-diver surveys. The Eastern Mediterranean includes non-indigenous species, so the effect of the MPA was also evaluated for its resistance to invasion. The fine-scale analysis revealed ecological phenomena that could not be captured by dichotomic sampling, such as the edge effect, a reduction of fish biomass along the MPA periphery. Despite their differences, all three methods revealed similar spatial patterns. The fine-scale analysis did not support a biotic resistance of the MPA to non-indigenous species. Our study supports the prevalence of edge effects even in well-enforced no-take MPAs and highlights the need for continuous monitoring to reveal these patterns.

Assessing the multiple benefits of partially protected marine protected areas in Australia: A systematic review protocol.

There is global pressure to protect more of the world's oceans, primarily to protect biodiversity, and to fulfill the "30 by 30" goal set by the International Union for the Conservation of Nature (IUCN) that has recently been ratified under the Kunming-Montreal Global Biodiversity Framework at the fifteenth Conference of Parties (COP-15). Fully protected marine protected areas (MPAs) provide the highest level of protection for biodiversity from destructive or extractive practices and may limit access to the area itself. Fully protected MPAs (also commonly referred to as 'no-take MPAs') ban all fishing activities, thereby removing the realisation of direct economic and social benefits from resource extraction within these areas. However, fully protected MPAs can still act as source of productivity to surrounding areas, while also providing an important scientific reference role for off-reserve management thereby providing indirect economic and social outcomes, as well as biodiversity benefits. Sustainable marine resource management strives to achieve 'triple-bottom line' benefits, where economic, social, and biodiversity benefits are maximised in managed areas of the ocean. Implementing 'partially protected' areas (PPAs) in areas of high biodiversity value (i.e., inshore, productive areas of the ocean) that allow for some extractive activities, may allow us to supplement fully MPAs to meet IUCN conservation goals, while maximising social and economic benefits. However, our current understanding lacks explicit quantitative assessments of whether and how PPAs can benefit (or otherwise) biodiversity, while also providing economic and social benefits. This study provides a method to systematically review the scientific and legislative literature to understand how PPAs may contribute to conserving biodiversity while also providing social and economic benefits to Australia. The implementation of partially protected areas (PPAs) requires careful consideration of many potentially competing factors, and an understanding of the types of partial protection already in place in a region. We have developed a systematic literature review protocol focussing on the primary research question: "What is the current state of partially protected area (PPA) implementation across Australian marine areas?". The aim of the review is to provide marine resource managers with a comprehensive overview of PPAs in Australia, including associated goals and stated management strategies to achieve these goals, and a methodological approach that may be utilised globally. The review protocol was designed by the research team for a Fisheries Resource and Development Corporation (FRDC) strategic research grant and will seek input from a project steering committee for the project on aggregation of the initial results. The steering committee is made up of stakeholders from a wide range of backgrounds and interests, covering marine conservation, fisheries management, Indigenous values, and academic research in Australia. Multiple academic databases, alongside Australian Federal, State, and Territory legislation and related policies will be reviewed using Boolean keyword search strings for both academic databases and relevant grey literature. Results from eligible documents will be compiled and insights from the review collated to provide information on the status of PPA implementation in Australia.

Marine protected areas are linked to higher predation rates by fish in shallow urbanised reefs, but only in no-take reserves

Marine protected areas (MPAs) in which fishing is limited are a widespread management strategy to protect marine ecosystems. While many studies show clear effects of MPAs on fish biomass, much less is known about how protection influences the strength of ecological processes such as herbivory and predation. We characterised fish assemblages and used feeding assays to contrast rates of herbivory and predation by fish in MPAs (no-take and those with partial protection) and in fished sites in Sydney, Australia’s largest city. In no-take MPAs, large fish were more abundant, species richness was greater, and the biomass of predatory, herbivorous and all fish combined was higher. In contrast, sites with partial protection were indistinguishable from fished sites. Predation was higher in no-take MPAs than in partially protected MPAs, while herbivory was less influenced by protection status. These results show that protection from fishing within urbanised reefs can facilitate energy flow to higher trophic levels via increases in predation.

Spatial modeling reveals a growing threat to the world's largest rhodolith beds

Rhodolith beds comprise a highly biodiverse and productive ecosystem that dominates the mid and outer shelf of the tropical eastern South American coast. Conservation planning and specific conservation measures are lacking, while impacts over rhodolith beds are escalating due to carbonate mining, and other activities such as oil and gas exploration and seaport dredging. Primary data detailing the spatial extent and characteristics of rhodolith beds within the Brazilian Economic Exclusive Zone (EEZ) depend on extensive acoustic surveys and ground truthing, which are costly and logistically challenging. Here, we compiled an extensive database of rhodolith occurrence from the scientific and grey literature. ‘Ensemble’ Ecological Niche Modelling (EENM) techniques predicted the total area suitable for rhodoliths across the Brazilian EEZ and gave insight into the environmental variables driving their distribution in this region. Using the suitability map produced from the ensemble model, we compared rhodolith spatial overlap with oil and gas and mining activities and marine protected areas (MPAs). Light, saturation state of calcite and minimum temperature were the main predictors of rhodolith occurrence. Rhodoliths were predicted to occur over ∼167,379 km2 of the Brazilian EEZ largely (∼95%) in the Amazonas (AM), Northeastern Brazil (NB) and Eastern Brazil (EB) ecoregions. The representation of rhodoliths in areas with mining and oil and gas activities was similar for the EEZ as a whole. Within each ecoregion, representation of rhodolith beds in MPAs is negatively related with their overlap with mining and oil and gas activities. Eastern Brazil (EB) stood out as the area with the highest representation of rhodoliths under threat, in an area 6.7 times larger than those represented in MPAs, including the south region of the largest continuous extension of rhodolith beds, in the Abrolhos bank. Within the NB and AM ecoregions, which are under growing industrialization, rhodolith beds are poorly represented in no-take MPAs. Our results provide a basis for moving toward more effective management and conservation strategies for rhodolith beds in Brazil's EEZ.

Protection from fishing improves body growth of an exploited species.

Hunting and fishing are often size-selective, which favours slow body growth. In addition, fast growth rate has been shown to be positively correlated with behavioural traits that increase encounter rates and catchability in passive fishing gears such as baited traps. This harvest-induced selection should be effectively eliminated in no-take marine-protected areas (MPAs) unless strong density dependence results in reduced growth rates. We compared body growth of European lobster (Homarus gammarus) between three MPAs and three fished areas. After 14 years of protection from intensive, size-selective lobster fisheries, the densities in MPAs have increased considerably, and we demonstrate that females moult more frequently and grow more during each moult in the MPAs. A similar, but weaker pattern was evident for males. This study suggests that MPAs can shield a wild population from slow-growth selection, which can explain the rapid recovery of size structure following implementation. If slow-growth selection is a widespread phenomenon in fisheries, the effectiveness of MPAs as a management tool can be higher than currently anticipated.

Nearshore marine biodiversity of Osa Peninsula, Costa Rica: Where the ocean meets the rainforest.

Osa Peninsula in remote southwest Costa Rica harbors 2.5% of global terrestrial biodiversity in only 1,200 km2 and has the largest remaining tract of Pacific lowland wet forest in Mesoamerica. However, little is known about the marine ecosystems of this diverse region. Much of the coastline consists of soft sediment exposed to strong wave action. Three major hard bottom habitat types define this region, including: 1) coral reefs around Isla del Caño Biological Reserve, a no-take marine protected area (MPA) of 52 km2, 2) coastal rocky reefs and islets along the peninsula, including Corcovado National Park, and 3) submerged pinnacles just outside the Isla del Caño MPA. Average coral cover at Isla del Caño was 21%, composed primarily of Porites lobata and Pocillopora elegans. In contrast, coastal rocky reefs were dominated by turf algae (39.8%) and macroalgae (20.7%) with low coral cover (1.1%). Submerged pinnacles were dominated by crustose coralline algae (33.3%) and erect coralline algae (25.7%). Fish assemblage characteristics (species richness, abundance, biomass) were significantly higher at the pinnacles compared to the other habitats and was dominated by schooling species such as Haemulon steindachneri, and the herbivores Kyphosus ocyurus, and Acanthurus xanthopterus. Top predators, primarily Triaenodon obesus, Caranx sexfasciatus, and Lutjanus argentimaculatus, were also most abundant at these pinnacles and accounted for the largest differences in fish trophic structure among habitats. Despite Isla del Caño being fully protected from fishing, biomass was similar to fished areas along the coast and lower than the adjacent submerged pinnacles outside the reserve. Similarly, Corcovado National Park includes 20.3 km2 of no-take MPAs; however, there is limited enforcement, and we noted several instances of fishing within the park. The unique configuration of healthy offshore coral reefs and pinnacles connected to coastal habitats provides corridors for many species including large predators such as sharks and other marine megafauna, which warrants additional protection.

Predator-derived bioregions in the Southern Ocean: Characteristics, drivers and representation in marine protected areas

Multiple initiatives have called for large-scale representative networks of marine protected areas (MPAs). MPAs should be ecologically representative to be effective, but in large, remote regions this can be difficult to quantify and assess. We present a novel bioregionalization for the Southern Ocean, which uses the modelled circumpolar habitat importance of 17 marine bird and mammal species. The habitat-use of these predators indicates biodiversity patterns that require representation in Southern Ocean conservation and management planning. In the predator habitat importance predictions, we identified 17 statistical clusters, falling into four larger groups. We characterized and contrasted these clusters based on their predator, prey and oceanographic characteristics. Under the existing Southern Ocean MPA network, some clusters fall short of 10 % representation, yet others meet or exceed these targets. Implementation of currently proposed MPAs can in some cases contribute to meeting even 30 % spatial coverage conservation targets. However, the effectiveness of mixed-use versus no-take MPAs should be taken into consideration, since some clusters are not adequately represented by no-take MPAs. These results, combined with previous studies in the Southern Ocean, can help inform the continued design, implementation, and evaluation of a representative system of MPAs for Southern Ocean conservation and management.

External fishing effort regulates positive effects of no-take marine protected areas

Marine protected areas (MPAs) have been established across the globe to mitigate the effects of multiple stressors on marine communities. In many locations, MPAs have generated positive effects on fish communities, but the impacts of fishing pressure—the primary stressor MPAs seek to manage—have not been well investigated. We examined changes in fish biomass inside and outside of no-take MPAs over 14 years in central California, USA. Using data from the community-based science program, the California Collaborative Fisheries Research Program, we tested which environmental and human-induced stressors most influence the strength of MPA responses. While temperature and productivity were included in the best fit model, we found that fine-scale fishing effort data, following reserve implementation, best explained the spatial variation in fish community responses to MPAs. Specifically, differences in fish biomass between MPAs and sites open to fishing were larger for reserves near heavily fished locations and these areas exhibited the highest rate of change in fish biomass, indicating strong positive effects of the MPA on the most heavily exploited fish communities. As MPAs continue to be used as a prominent conservation strategy in coastal systems, managers should consider both the suite of human-induced (socio-ecological interactions) and environmental conditions that may alter MPA success as well as establish long-term monitoring programs to fully assess the functionality of marine reserves into the future.

Using movement models and systematic conservation planning to inform marine protected area design for a multi-species predator community

Marine protected areas (MPAs) are increasingly applied to regulate fishing and conserve marine biodiversity. Yet, MPAs are often designed without sufficient ecological knowledge of the species they are intended to protect. This is particularly relevant to large and wide-ranging marine predators including many elasmobranchs (sharks and rays), for which region-specific space-use information is limited. Further, uncertainty remains in how to integrate movement datasets with systematic conservation planning frameworks to meet explicit conservation objectives. We addressed these knowledge gaps by combining movement models, constructed from passive acoustic telemetry data for eight elasmobranch species, and systematic conservation planning to investigate the design and adequacy of MPAs in Bimini, The Bahamas. Currently, there is a proposal for a no-take MPA in North Bimini (NBMPA), although it is unclear how this MPA would benefit elasmobranch communities if or when implemented. Our results show that although the NBMPA would contribute to elasmobranch conservation, the supplementation with an additional MPA southwest of Bimini would be necessary to protect important habitats for multiple elasmobranch species. This southwestern area was highlighted as a conservation priority area of both permanent MPA designs as well as seasonal time-area closures, regardless of NBMPA implementation status and conservation targets considered in this study. Our integrative approach also demonstrates its ability to optimize MPA designs for marine predator communities, combining multi-species movement models, constructed from acoustic telemetry datasets that include space-use estimates over multiple years, with MPA optimization tools.

Self-financed marine protected areas

Marine protected areas (MPAs) are an important tool for conservation but can be victims of their own success—higher fish biomass within MPAs create incentives to poach. This insight underpins the finding that fishing persists in most MPAs worldwide, and it raises questions about MPA monitoring and enforcement. We propose a novel institution to enhance MPA design—a ‘Conservation Finance Area (CFA)’—that utilizes leased fishing zones inside of MPAs, fed by spillover, to finance monitoring and enforcement and achieve greater conservation success. Using a bioeconomic model we show that CFAs can fully finance enforcement, deter illegal fishing, and ultimately maximize fish biomass. Moreover, we show that unless a large, exogenous, and perpetual enforcement budget is available, implementing a CFA in a no-take MPA would always result in higher biomass than without. We also explore real-world enabling conditions, providing a plausible funding pathway to improve outcomes for existing and future MPAs.