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Many shark populations are in decline around the world, with severe ecological and economic consequences. Fisheries management and marine protected areas (MPAs) have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays ('elasmobranchs'), with little known about how fisheries management and MPAs interact to conserve these species. Here we use a dedicated global survey of coral reef elasmobranchs to assess 66 fully protected areas embedded within a range of fisheries management regimes across 36 countries. We show that conservation benefits were primarily for reef-associated sharks, which were twice as abundant in fully protected areas compared with areas open to fishing. Conservation benefits were greatest in large protected areas that incorporate distinct reefs. However, the same benefits were not evident for rays or wide-ranging sharks that are both economically and ecologically important while also threatened with extinction. We show that conservation benefits from fully protected areas are close to doubled when embedded within areas of effective fisheries management, highlighting the importance of a mixed management approach of both effective fisheries management and well-designed fully protected areas to conserve tropical elasmobranch assemblages globally., (© 2024. Crown.)

Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status 1,2 . Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats 3 . Here we address this knowledge gap using data from more than 15,000 standardized baited remote underwater video stations that were deployed on 371 reefs in 58 nations to estimate the conservation status of reef sharks globally. Our results reveal the profound impact that fishing has had on reef shark populations: we observed no sharks on almost 20% of the surveyed reefs. Reef sharks were almost completely absent from reefs in several nations, and shark depletion was strongly related to socio-economic conditions such as the size and proximity of the nearest market, poor governance and the density of the human population. However, opportunities for the conservation of reef sharks remain: shark sanctuaries, closed areas, catch limits and an absence of gillnets and longlines were associated with a substantially higher relative abundance of reef sharks. These results reveal several policy pathways for the restoration and management of reef shark populations, from direct top-down management of fishing to indirect improvement of governance conditions. Reef shark populations will only have a high chance of recovery by engaging key socio-economic aspects of tropical fisheries.

Species-specific biological data are commonly combined with fishery operational data to model exploited stocks and determine appropriate levels of exploitation. However, this approach to fishery management is predicated using the' to 'predicated on the ability of fishery data collectors to correctly identify exploited species. Sharks and other elasmobranch fishes (Elasmobranchii) can be particularly difficult to identify in the field, due to the close physical similarity to other species and/or a lack of taxonomic resolution in some lineages. This paper provides an overview of the difficulties surrounding the field identification of a number of elasmobranch species found in the Arabian/Persian Gulf, where they are heavily exploited and in urgent need of careful management. [ABSTRACT FROM AUTHOR]

Sets of baited hooks decrease in fishing efficacy over time as catch accumulates and bait is lost, and this complicates the quantification of fishing effort for species abundance calculations. Although hook-timers facilitate a more accurate estimation of fishing time, they cannot provide taxonomic information in the case of escapees or bait loss, nor can they provide information on animals that approach the gear but do not physically engage with it. To overcome these limitations, the present study attached sport action cameras to baited drumlines during a catch-and-release survey of sharks in the shallow, coastal waters of the eastern Caicos Bank, Turks and Caicos Islands. Overall, the true fishing time was found to be appreciably less than the apparent fishing time and more sharks approached or interacted with the gear than were successfully captured by it. Furthermore, shark-gear interactions varied by species while the amount of bait loss differed between deployment areas. Taken together, these findings suggest that baited-hook surveys underestimate shark abundance and that the magnitude of this error varies by species and habitat type. • Bait loss results in a substantial reduction in the active fishing time of drumlines. • Baited hooks do not successfully capture all sharks that are attracted to the gear. • Shark interactions with baited drumlines vary by species. • Catch-per-unit-effort values for sharks derived from baited-hook surveys are negatively biased. [ABSTRACT FROM AUTHOR]

Abstract: The Sultanate of Oman has a long established traditional shark fishery, which has experienced increased demand in recent years due to the shark fin trade. Despite the long history of the fishery in Oman and neighbouring countries, few studies have been undertaken to determine the biological characteristics of the fishery or its ability to withstand this increased exploitation. The present study was undertaken as a first step to remedying this situation. A total of 47 species was confirmed from Oman''s coastal waters, of which 44 occurred in commercial landings. However, landings were dominated by eight species—Rhizoprionodon acutus, Iago omanensis, Carcharhinus sorrah, Loxodon macrorhinus, C. macloti, C. limbatus, Sphyrna lewini and C. falciformis. The species composition of landings varied along the coast and also with season. Brillouin Index values indicated that species diversity was greatest in the Muscat area, followed closely by Musandam. The Al-Wusta region displayed the lowest diversity. The occurrence of two uncommon shark species, Chaenogaleus macrostoma and Echinorhinus brucus, was of interest, as was the recording of a juvenile Carcharhinus galapagensis, extending its northern range in the Indian Ocean considerably. [Copyright &y& Elsevier]