Reserve sizes needed to protect coral reef fishes

Marine reserves are a commonly applied conservation tool, but their size is often chosen based on considerations of socioeconomic rather than ecological impact. Here, we use a simple individual-based model together with the latest empirical information on home ranges, densities and schooling behaviour in 66 coral reef fishes to quantify the conservation effectiveness of various reserve sizes. We find that standard reserves with a diameter of 1-2 km can achieve partial protection (50% of the maximum number of individuals) of 56% of all simulated species. Partial protection of the most important fishery species, and of species with diverse functional roles, required 2-10 km wide reserves. Full protection of nearly all simulated species required 100 km wide reserves. Linear regressions based on the mean home range and density, and even just the maximum length, of fish species approximated these results reliably, and can therefore be used to support locally effective decision making

The inclusion of fisheries and tourism in marine protected areas to support conservation in Indonesia

With the rapid growth of Indonesia’s marine protected area (MPAs) estate in Indonesia, reaching 23.9 million hectares by January 2020, attention needs to be focused on strengthening the effectiveness of MPA management. Consolidating and expanding protection of Indonesia’s marine resources is critical with increasing pressure from a fast-expanding population, illegal, unreported, and unregulated fishing, pollution, coastal development, unsustainable tourism and climate change. Biodiversity conservation must therefore concurrently consider multiple economic sectors such as fisheries and tourism, and their synergies with MPA management. This paper aims to outline the current landscape of fisheries and marine tourism pertaining to area-based conservation in Indonesia, to inform and support improved integration into effective MPA management. Four areas to focus efforts were identified: diversification of governance types of community-based management, improved coordination between fisheries and MPAs during planning and management implementation, the development and support of pathways for sustainable tourism, and planning for future conditions. Sustainable development for fisheries and tourism must be incorporated into all aspects of MPA management, whilst recognising that current management systems are insufficient to ensure long-term sustainability for natural resources and local communities, and strategies need to increase resilience of social-ecological systems in anticipation of future conditions

Marine protected areas can benefit biodiversity even when bycatch species only partially overlap fisheries

Publication status: PublishedFunder: Cambridge Australia Poynton ScholarshipFunder: Royal Society Wolfson Research Merit AwardAbstract Marine protected areas (MPAs) are increasingly relied upon to preserve biodiversity and ensure fisheries sustainability. Although recent analyses have shown that MPAs can provide overall biodiversity benefits even when they only redistribute fishing effort, these did not account for refuges outside of fishing grounds for non‐target species. It has been argued that such refuges could render MPAs obsolete where their chief benefit is to ensure species persistence. Here, we modelled the outcomes associated with placing MPAs within a seascape where non‐target species' ranges can extend beyond fishing grounds. In scenarios with no explicit fishing‐induced habitat damage, we found that MPAs provided a net biodiversity benefit so long as there was at least an approximately 60% overlap between fishing grounds and non‐target species' ranges. In scenarios with explicit fishing‐induced habitat damage for non‐target species, we found that MPAs instead benefitted biodiversity at all overlaps, but that this was reduced if target species' abundances also declined with damage. Additionally, we identified counterintuitive mechanisms by which MPAs could either help or harm the same species depending on their location by changing fishing effort distribution patterns. However, MPAs did always increase the total fishing effort required to reach a catch target. Policy implications: Our results showed that MPAs could still deliver biodiversity benefits in otherwise well‐regulated fisheries when species' ranges and fishing grounds did not fully overlap, and particularly when sensitive species and habitats were present. Well‐placed MPAs should thus be considered in such settings. However, MPAs were also less likely to be useful when range overlaps were low and always resulted in higher fishing effort to maintain the same catches. </jats:p

Marine protected areas can benefit biodiversity even when bycatch species only partially overlap fisheries

1. Marine protected areas (MPAs) are increasingly relied upon to preserve biodiversity and ensure fisheries sustainability. Although recent analyses have shown that MPAs can provide overall biodiversity benefits even when they only redistribute fishing effort, these did not account for refuges outside of fishing grounds for non-target species. It has been argued that such refuges could render MPAs obsolete where their chief benefit is to ensure species persistence. 2. Here, we modelled the outcomes associated with placing MPAs within a seascape where non-target species’ ranges can extend beyond fishing grounds. 3. In scenarios with no explicit fishing-induced habitat damage, we found that MPAs provided a net biodiversity benefit so long as there was at least an approximately 60% overlap between fishing grounds and non-target species’ ranges. In scenarios with explicit fishing-induced habitat damage for non-target species, we found that MPAs instead benefitted biodiversity at all overlaps, but that this was reduced if target species’ abundances also declined with damage. 4. Additionally, we identified counterintuitive mechanisms by which MPAs could either help or harm the same species depending on their location by changing fishing effort distribution patterns. However, MPAs did always increase the total fishing effort required to reach a catch target. 5. Policy implications: Our results showed that MPAs could still deliver biodiversity benefits in otherwise well-regulated fisheries when species’ ranges and fishing grounds did not fully overlap, and particularly when sensitive species and habitats were present. Well-placed MPAs should thus be considered in such settings. However, MPAs were also less likely to be useful when range overlaps were low, and always resulted in higher fishing effort to maintain the same catches.PE is funded by a Cambridge Australia Poynton Scholarship, AB a Royal Society Wolfson Research Merit Award, MHH an Australian Research Council Discovery Early Career Researcher Award (DE190101416), and NT a MEXT Advancement of Technologies for Utilizing Big Data of Marine Life Award (JPMXD1521469887)

Ocean currents and the population genetic signature of fish migrations

Animal migrations are a fascinating and global phenomenon, yet they are often difficult to study and sometimes poorly understood. Here, we build on classic ecological theory by hypothesizing that some enigmatic spawning migrations across coastal marine habitats can be inferred from the population genetic signature of larval dispersal by ocean currents. We test this assumption by integrating spatially realistic simulations of alternative spawning migration routes, associated patterns of larval dispersal, and associated variation in the population genetic structure of eastern Australian sea mullet (Mugil cephalus). We then use simulation results to assess the implications of alternative spawning destinations for larval replenishment, and we contrast simulated against measured population genetic variation. Both analyses suggest that the spawning migrations of M. cephalus in eastern Australia are likely to be localized (approximately 100 km along the shore), and that spawning is likely to occur in inshore waters. Our conclusions are supported by multiple lines of evidence available through independent studies, but they challenge the more traditional assumption of a single, long-distance migration event with subsequent offshore spawning in the East Australian Current. More generally, our study operationalizes classic theory on the relationship between fish migrations, ocean currents, and reproductive success. However, rather than confirming the traditionally assumed adaptation of migratory behavior to dominant ocean current flow, our findings support the concept of a genetically measurable link between fish migrations and local oceanographic conditions, specifically water temperature and coastal retention of larvae. We believe that future studies using similar approaches for high resolution and spatially realistic ecological–genetic scenario testing can help rapidly advance our understanding of key ecological processes in many other marine species

Quantitative decision support tools facilitate social-ecological alignment in community-based marine protected area design

Marine protected areas (MPAs) are increasingly used to support both biodiversity conservation and fisheries management. However, MPA performance is likely to be compromised if people who depend on fishing are excluded from MPA design decision making. Participatory MPA design helps to address this problem by engaging local stakeholders in all critical decisions, including the total coverage, placement, and local size of no-take marine reserves. Here, we report the findings from a participatory MPA design project on Selayar Island, Indonesia, in which a community initiated collaborations with scientists to access modern quantitative tools for community-led MPA scenario testing. The outcomes highlight a local disagreement between ecologically and socially desirable MPA designs. Focused on social considerations, the initial community-supported MPA design consisted of four small reserves (0.5–1 km wide) in predominately southern community waters, where they were intended to restrict external fishers. Ecologically optimal MPA designs, in contrast, consisted of one or two large reserves (4–6 km wide) in northern community waters, where they were expected to restrict primarily local fishers but better support the rebuilding of fish populations and fisheries. However, ecologically optimal MPA designs were socially infeasible. Using quantitative MPA performance assessments, the community negotiated an alternative MPA design consisting of two 1.5–2 km wide reserves at socially and ecologically favorable locations. Compared to the initial proposal, this revised MPA design was estimated (1) to protect three to four times more individuals of key fishery species within reserve boundaries and (2) to double local fishery catches. We conclude that even simple MPA design tools, which quantify and visualize local conservation and fishery outcomes under alternative MPA scenarios, add value to participatory decision making and likely MPA performance

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

BackgroundThere 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.Methods and expected outputsThe 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

Correction to: Ocean zoning within a sparing versus sharing framework

The article “Ocean zoning within a sparing versus sharing framework,” written by Jennifer McGowan, Michael Bode, Matthew H. Holden, Katrina Davis, Nils C. Krueck, Maria Beger, Katherine L. Yates, and Hugh P. Possingham, was originally published electronically on the publisher’s internet portal

Individual and population benefits of marine reserves for reef sharks

No-take marine protected areas (MPAs) are a commonly applied tool to reduce human fishing impacts on marine and coastal ecosystems. However, conservation outcomes of MPAs for mobile and long-lived predators such as sharks are highly variable. Here, we use empirical animal tracking data from 459 individual sharks and baited remote underwater video surveys undertaken in 36 countries to construct an empirically supported individual-based model that estimates the conservation effectiveness of MPAs for five species of coral reef-associated sharks (Triaenodon obesus, Carcharhinus melanopterus, Carcharhinus amblyrhynchos, Carcharhinus perezi, and Ginglymostoma cirratum). We demonstrate how species-specific individual movement traits can contribute to fishing mortality of sharks found within MPAs as they move outside to adjacent fishing grounds. We discovered that the world's officially recorded coral reef-based managed areas (with a median width of 9.4 km) would need to be enforced as strict no-take MPAs and up to 5 times larger to expect protection of the majority of individuals of the five investigated reef shark species. The magnitude of this effect depended on local abundances and fishing pressure, with MPAs required to be 1.6-2.6 times larger to protect the same number of Atlantic and Caribbean species, which occur at lower abundances than similar species in the western Pacific. Furthermore, our model was used to quantify partially substantial reductions (>50%) in fishing mortality resulting from small increases in MPA size, allowing us to bridge a critical gap between traditional conservation planning and fisheries management. Overall, our results highlight the challenge of relying on abundance data alone to ensure that estimates of shark conservation impacts of MPAs follow the precautionary approach