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The efficacy of large marine protected areas (MPA) for the conservation of mobile pelagic species is widely debated. Here, we quantified spatial and temporal trends in standardized catch per unit effort (CPUE) of two target pelagic species, yellowfin (Thunnus albacares) and bigeye tuna (Thunnus obesus) in the Indian Ocean to analyze the impact of the British Indian Ocean Territory (BIOT) MPA's creation in 2010. We applied generalized additive mixed effects models to historical BIOT longline fishery logbooks and official catch and effort statistics from the Indian Ocean Tuna Commission (IOTC) to standardize CPUEs and to evaluate long-term trends and distribution patterns across the equatorial Indian Ocean. We find that trends in population indices from within BIOT prior to the MPA's establishment mirror those of the wider Indian Ocean. We also suggest that there may be behavioral plasticity within the yellowfin tuna stock, with some individuals possibly undertaking alternative migration patterns or exhibiting residency behavior within BIOT. Yet, we find no direct evidence of any improvement in standardized CPUE indices of either species in the area surrounding the BIOT MPA, nearly 8 years after its establishment. The average size of yellowfin and bigeye tunas caught both increased after the MPA's establishment. These patterns were also evident across the equatorial Indian Ocean, suggesting that any MPA effect is in combination with other regional drivers, such as behavioral changes in the fishing fleets in response to the threat of Somali Piracy. We therefore conclude that BIOT MPA may be providing local conservation value to tunas, but it is not significant enough to halt the overall regional decline in yellowfin tuna stocks. Thus, we emphasize that large MPAs should be considered in conjunction with other fishery management regulations and wider regional processes, rather than as a silver bullet, in order to provide the conservation and management benefits needed f

The efficacy of large marine protected areas (MPA) for the conservation of mobile pelagic species is widely debated. Here, we quantified spatial and temporal trends in standardized catch per unit effort (CPUE) of two target pelagic species, yellowfin (Thunnus albacares) and bigeye tuna (Thunnus obesus) in the Indian Ocean to analyze the impact of the British Indian Ocean Territory (BIOT) MPA's creation in 2010. We applied generalized additive mixed effects models to historical BIOT longline fishery logbooks and official catch and effort statistics from the Indian Ocean Tuna Commission (IOTC) to standardize CPUEs and to evaluate long-term trends and distribution patterns across the equatorial Indian Ocean. We find that trends in population indices from within BIOT prior to the MPA's establishment mirror those of the wider Indian Ocean. We also suggest that there may be behavioral plasticity within the yellowfin tuna stock, with some individuals possibly undertaking alternative migration patterns or exhibiting residency behavior within BIOT. Yet, we find no direct evidence of any improvement in standardized CPUE indices of either species in the area surrounding the BIOT MPA, nearly 8 years after its establishment. The average size of yellowfin and bigeye tunas caught both increased after the MPA's establishment. These patterns were also evident across the equatorial Indian Ocean, suggesting that any MPA effect is in combination with other regional drivers, such as behavioral changes in the fishing fleets in response to the threat of Somali Piracy. We therefore conclude that BIOT MPA may be providing local conservation value to tunas, but it is not significant enough to halt the overall regional decline in yellowfin tuna stocks. Thus, we emphasize that large MPAs should be considered in conjunction with other fishery management regulations and wider regional processes, rather than as a silver bullet, in order to provide the conservation and management benefits needed f

Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific by using 1,041 midwater baited videos to survey sharks and other pelagic predators such as rainbow runner (Elagatis bipinnulata), mahi-mahi (Coryphaena hippurus), and black marlin (Istiompax indica). We modeled three key predator community attributes: vertebrate species richness, mean maximum body size, and shark abundance as a function of geomorphology, environmental conditions, and human pressures. All attributes were primarily driven by geomorphology (35%−62% variance explained) and environmental conditions (14%−49%). While human pressures had no influence on species richness, both body size and shark abundance responded strongly to distance to human markets (12%−20%). Refuges were identified at more than 1,250 km from human markets for body size and for shark abundance. These refuges were identified as remote and shallow seabed features, such as seamounts, submerged banks, and reefs. Worryingly, hotpots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take

There are two textual errors in the published paper. In the Abstract, the last line reads “hotpots” instead of “hotspots.” The same textual error is present in the Introduction. The last line of the Abstract should read as follows: Worryingly, hotspots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations. The first line of the last paragraph of the Introduction should read as follows: Here, we utilize an extensive data set of standardized and nondestructive baited video surveys from nine regions across the Indo-Pacific region to model predator diversity and abundance and to identify hotspots of vertebrate species richness, mean maximum body size weighted by abundance (hereafter “body size”), and shark abundance as a function of environmental conditions, geomorphology, human pressure, and management levels. The funding statement also ommits funding received from the Centre for the Synthesis and Analysis of Biodiversity. The amended Financial Disclosure should read as follows: This work was supported by the Australian Government’s National Environmental Research Program (NERP) Marine Biodiversity Hub (TBL, PB, JC, JJM) and by the Bertar-elli Foundation (TBL, JJM). Additional support was provided by Darwin Initiative grant (Project #19027, HK), Centre for the Synthesis and Analysis of Biodiversity (CESAB, TBL, DM, LV, JBJ, JJM), Total Foundation (PELAGIC Project, TBL, DM, LV, JBJ, JJM), French Oceanic Fleet and New Caledonian Government Pristine reef and Apex grants (DM, LV), and National Geographic’s Pristine Seas programme (AF, ES).’

There are two textual errors in the published paper. In the Abstract, the last line reads “hotpots” instead of “hotspots.” The same textual error is present in the Introduction. The last line of the Abstract should read as follows: Worryingly, hotspots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations. The first line of the last paragraph of the Introduction should read as follows: Here, we utilize an extensive data set of standardized and nondestructive baited video surveys from nine regions across the Indo-Pacific region to model predator diversity and abundance and to identify hotspots of vertebrate species richness, mean maximum body size weighted by abundance (hereafter “body size”), and shark abundance as a function of environmental conditions, geomorphology, human pressure, and management levels. The funding statement also ommits funding received from the Centre for the Synthesis and Analysis of Biodiversity. The amended Financial Disclosure should read as follows: This work was supported by the Australian Government’s National Environmental Research Program (NERP) Marine Biodiversity Hub (TBL, PB, JC, JJM) and by the Bertar-elli Foundation (TBL, JJM). Additional support was provided by Darwin Initiative grant (Project #19027, HK), Centre for the Synthesis and Analysis of Biodiversity (CESAB, TBL, DM, LV, JBJ, JJM), Total Foundation (PELAGIC Project, TBL, DM, LV, JBJ, JJM), French Oceanic Fleet and New Caledonian Government Pristine reef and Apex grants (DM, LV), and National Geographic’s Pristine Seas programme (AF, ES).’

Seahorses (family Syngnathidae, genus Hippocampus) have set precedents globally. They were among the first marine fishes of commercial importance to be listed on both the IUCN Red List and CITES Appendix II. Overfishing and non-selective fishing are two agents in their depletion, so management is clearly needed. We here outline what is known about these fishes and their trade, before considering the potential role the culture and release could play in rebuilding wild populations.