Global mercury concentrations in biota: their use as a basis for a global biomonitoring framework

Ecotoxicology, Год журнала: 2024, Номер 33(4-5), С. 325 - 396

Опубликована: Апрель 29, 2024

Abstract An important provision of the Minamata Convention on Mercury is to monitor and evaluate effectiveness adopted measures its implementation. Here, we describe for first time currently available biotic mercury (Hg) data a global scale improve understanding efforts reduce impact Hg pollution people environment. Data from peer-reviewed literature were compiled in Global Biotic Synthesis (GBMS) database (>550,000 points). These provide foundation establishing biomonitoring framework needed track concentrations biota globally. We exposure taxa identified by Convention: fish, sea turtles, birds, marine mammals. Based GBMS database, are presented at relevant geographic scales continents oceanic basins. identify some effective regional templates monitoring methylmercury (MeHg) availability environment, but overall illustrate that there general lack initiatives around world, especially Africa, Australia, Indo-Pacific, Middle East, South Atlantic Pacific Oceans. Temporal trend generally limited. Ecologically sensitive sites (where have above average MeHg tissue concentrations) been throughout world. Efforts model quantify ecosystem sensitivity locally, regionally, globally could help establish efficient programs. present network includes three-step continental approach integrate existing prioritize filling gaps linked with key sources. standardized builds an evidence-based evaluation assess Convention’s progress

Язык: Английский

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Prevalence of endangered shark trophies in automated detection of the online wildlife trade

Biological Conservation, Год журнала: 2025, Номер 304, С. 110992 - 110992

Опубликована: Фев. 19, 2025

Язык: Английский

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The vulnerability of sharks, skates, and rays to ocean deoxygenation: Physiological mechanisms, behavioral responses, and ecological impacts

Journal of Fish Biology, Год журнала: 2024, Номер 105(2), С. 482 - 511

Опубликована: Июнь 9, 2024

Abstract Levels of dissolved oxygen in open ocean and coastal waters are decreasing (ocean deoxygenation), with poorly understood effects on marine megafauna. All the more than 1000 species elasmobranchs (sharks, skates, rays) obligate water breathers, a variety life‐history strategies requirements. This review demonstrates that although many typically avoid hypoxic water, they also appear capable withstanding mild to moderate hypoxia changes activity, ventilatory responses, alterations circulatory hematological parameters, morphological gill structures. However, such may be insufficient withstand severe, progressive, or prolonged anoxia where anaerobic metabolic pathways used for limited periods. As temperatures increase climate warming, ectothermic will exhibit elevated rates likely less able tolerate even associated deoxygenation. result, sustained conditions warmer surface‐pelagic lead shifts elasmobranch distributions. Mass mortalities linked directly deoxygenation have only rarely been observed but underreported. One key concern is how reductions habitat volume as result expanding resulting from influence interactions between industrial fisheries. Catch per unit effort threatened pelagic sharks by longline fisheries, instance, has shown higher above minimum zones compared adjacent, normoxic regions, attributed vertical compression overlapping increased fishing effort. How compound stressor heatwaves alters vulnerability remains an question. With over third listed endangered, priority conservation management now lies understanding mitigating addition population declines already occurring overfishing.

Язык: Английский

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Discovery of a potential open ocean nursery for the endangered shortfin mako shark in a global fishing hotspot

Scientific Reports, Год журнала: 2025, Номер 15(1)

Опубликована: Янв. 16, 2025

Populations of large pelagic sharks are declining worldwide due to overfishing. Determining the overlap between shark populations and fishing activities is important inform conservation measures. However, for many threatened whereabouts particularly vulnerable life-history stages - such as pregnant females juveniles poorly known. Here, we investigated spatial distribution size classes, energy transfer reproductive states endangered shortfin mako, Isurus oxyrinchus, using spatially resolved catch data from a Spanish surface longline vessel (1996 2009) in South-east Pacific Ocean. Our results suggest general eastward gradient occurrence thousands kilometers western oceanic feeding grounds towards eastern Pacific, where observed an aggregation area small juveniles. Moreover, potential nursery likely overlapped hotspot, increasing vulnerability fisheries. that limiting pressure this could reduce mortality early life contribute species.

Язык: Английский

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Environmental and spatial modeling of the critically endangered sand tiger shark, Carcharias taurus, in the Southwest Atlantic Ocean

Environmental Biology of Fishes, Год журнала: 2025, Номер unknown

Опубликована: Янв. 24, 2025

Язык: Английский

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Ecological erosion and expanding extinction risk of sharks and rays

Science, Год журнала: 2024, Номер 386(6726)

Опубликована: Дек. 5, 2024

The true state of ocean biodiversity is difficult to assess, and there are few global indicators track the primary threat overfishing. We calculated a 50-year Red List Index extinction risk ecological function for 1199 sharks rays found that since 1970, overfishing has halved their populations worsened by 19%. Overfishing largest species in nearshore pelagic habitats risks loss ecomorphotypes 5 22% erosion functional diversity. Extinction higher countries with large human coastal but lower nations stronger governance, larger economies, greater beneficial fisheries subsidies. Restricting fishing (including incidental catch) trade sustainable levels combined prohibiting retention highly threatened can avert further depletion, widespread population connectivity, top-down predator control.

Язык: Английский

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Unseen overlap between fishing vessels and top predators in the northeast Pacific

Science Advances, Год журнала: 2024, Номер 10(10)

Опубликована: Март 6, 2024

Accurate assessments of human-wildlife risk associated with industrial fishing are critical for the conservation marine top predators. Automatic Identification System (AIS) data provide a means mapping and estimating risk; however, can be obscured by gaps in AIS record due to technical issues intentional disabling. We assessed extent which unseen vessel activity estimates overlap between 14 predators including sharks, tunas, mammals, seabirds, critically endangered leatherback turtles. Among vessels equipped northeast Pacific, up 24% total predator was unseen, 36% some individual species. Waters near 10°N had high sharks yet low reported shark catch, revealing potential discrepancies self-reported datasets. Accounting illuminates hidden risk, demonstrating challenges solutions transparent sustainable fisheries.

Язык: Английский

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Rays in the Shadows: Batoid Diversity, Occurrence, and Conservation Status in Fiji

Biology, Год журнала: 2024, Номер 13(2), С. 73 - 73

Опубликована: Янв. 26, 2024

Over recent decades, elasmobranchs (sharks, rays, and skates) have been increasingly recognized among the world’s most threatened marine wildlife, leading to heightened scientific attention. However, batoids (rays are relatively understudied, especially in Large Ocean States of Pacific. This synthesis compiles insights on batoid diversity occurrence Fiji’s waters by integrating a literature review, participatory science programs such as Great Fiji Shark Count (GFSC) Initiative, Projects Abroad (PA), Manta Project (MPF), iNaturalist, along with environmental DNA. Nineteen species from seven families were identified: 19 literature, 12 programs, six eDNA analysis. Notably, this study provides first photographic evidence for bentfin devil ray (Mobula thurstoni, Lloyd, 1908) Fiji. GFSC data indicated highest Western Division, spotted eagle rays (Aetobatus ocellatus, Kuhl, 1823) maskrays (Neotrygon sp.) being observed most. In-person interviews conducted PA provided information wedgefishes potentially sawfishes. MPF records iNaturalist uploads dominated reef manta (M. alfredi, Krefft, 1868), while pink whipray (Pateobatis fai, Jordan Seale, 1906) yielded DNA sequences. Overall, 68.4% face an elevated extinction risk based International Union Conservation Nature Red List criteria. Although caution is warranted older literature-based giant guitarfish (Glaucostegus typus, Anonymous [Bennett], 1830), stingaree (Plesiobatis daviesi, Wallace, 1967), lack sawfish verification, highlights effectiveness combined methodological approach establishing reference point understudied taxon

Язык: Английский

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Shark conservation requires mortality-limiting regulations amid global change

Trends in Ecology & Evolution, Год журнала: 2024, Номер 39(4), С. 320 - 322

Опубликована: Март 16, 2024

Язык: Английский

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Addressing illegal longlining and ghost fishing in the Galapagos marine reserve: an overview of challenges and potential solutions

Frontiers in Marine Science, Год журнала: 2024, Номер 11

Опубликована: Июнь 6, 2024

Despite regulations aimed at curbing shark finning and bycatch, fishing mortality rates continue to escalate, partly due unintended consequences of these policies which, along with illegal, unreported, unregulated ghost fishing, undermine conservation efforts. The ineffectiveness current curb highlights the pressing need for reevaluating strategies, especially in ecologically sensitive areas. In this context, debate on enforcing longlining bans multiple-use marine protected areas, including sanctuaries, is intensifying. Some argue total minimize incidental mortalities, while others highlight socioeconomic importance longlining, advocating alternative measures. 2000, longline was banned Galapagos Marine Reserve (GMR) as a precautionary measure prevent illegal sharks bycatch endangered, threatened, species. After 24 years enforcement, official anecdotal evidence indicate that small-scale tuna are increasing threats across reserve. This paper provides an overview controversy within GMR, incorporating scientific evidence, legal considerations, perceptions from community. We offer novel insights recommendations development fishery ecosystem approach fisheries. aims reconcile goals needs local communities, also proposing innovative solutions address longstanding surrounding GMR.

Язык: Английский

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