The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is a critical measure of global aquatic and terrestrial biodiversity status. It is also the basis for the Red List Index, which tracks extinction risk over time. Sharks, rays, and chimaeras (Chondrichthyes) have now been comprehensively assessed twice (1996–2011 and 2012–2021) with hindcast assessments from 1970 onward, yielding an unprece...

The status of many shark species worldwide is concerning due to a combination of their life-history traits and widespread exposure to threats, especially fishing. However, the intrinsic vulnerability of species differ given that life-history traits vary with environmental conditions. Here, we aim to assess the links between sharks’ reproductive strategy, maximum depth recorded, and environment occupied (shelf, deepwater and pe...

Populations of many elasmobranchs have decreased globally, with over a third of species threatened with an elevated risk of extinction, largely due to fishing pressure. In West Africa, a general lack of species-specific catch data limits the ability to implement effective management, despite significant elasmobranch catch. The aim of this study was to (1) assess landings of mobulid rays, along with other elasmobranch species,...

Acoustic telemetry has been used to monitor the movement of aquatic animals in a broad range of aquatic environments. Despite their importance, mangrove habitats are understudied for the spatial ecology of elasmobranchs, with acoustic telemetry rarely used inside mangrove habitats. One reason for this may be a general assumption that acoustic signals would not be able to be detected by receivers in such shallow, structurally c...

Many citizen scientists are highly motivated to help address the current extinction crisis. Their work is making valuable contributions to protecting species by raising awareness, identifying species occurrences, assessing population trends, and informing direct management actions, such as captive breeding. However, clear guidance is lacking about how to use existing citizen science data sets and how to design effective citize...

River sharks ( Glyphis spp.) and some sawfishes (Pristidae) inhabit riverine environments, although their long‐term habitat use patterns are poorly known. We investigated the diadromous movements of the northern river shark ( Glyphis garricki ), speartooth shark ( Glyphis glyphis ), narrow sawfish ( Anoxypristis cuspidata ), and largetooth sawfish ( Pristis pristis ) using in situ laser ablation inductively coupled plasma mass...

Marine protected areas (MPAs) are key tools in addressing the global decline of sharks and rays, and marine parks and shark sanctuaries of various configurations have been established to conserve shark populations. However, assessments of their efficacy are compromised by inconsistent terminology, lack of standardized approaches to assess how MPAs contribute to shark and ray conservation, and ambiguity about how to integrate m...

Fisheries management is essential to guarantee sustainable capture of target species and avoid undesirable declines of incidentally captured species. A key challenge is halting and reversing declines of shark and ray species, and specifically assessing the degree to which management is sufficient to avoid declines in relatively data‐poor fisheries. While ecological risk analyses focus on intrinsic ‘productivity’ and extrinsic...

Area-based conservation is essential to safeguard declining biodiversity. Several approaches have been developed for identifying networks of globally important areas based on the delineation of sites or seascapes of importance for various elements of biodiversity (e.g., birds, marine mammals). Sharks, rays, and chimaeras are facing a biodiversity crisis with an estimated 37% of species threatened with extinction driven by over...

Shark placentae are derived from modifications to the fetal yolk sac and the maternal uterine mucosa. In almost all placental sharks, embryonic development occurs in an egg capsule that remains intact for the entire pregnancy, separating the fetal tissues from the maternal tissues at the placental interface. Here, we investigate the structure and permeability of the egg capsules that surround developing embryos of the placenta...

Delineation of population structure (i.e. stocks) is crucial to successfully manage exploited species and to address conservation concerns for threatened species. Fish migration and associated movements are key mechanisms through which discrete populations mix and are thus important determinants of population structure. Detailed information on fish migration and movements is becoming more accessible through advances in telemet...

Marine protected areas ( MPA s) are increasingly advocated for the conservation and management of sharks and rays. However, substantial uncertainty remains regarding which species can benefit from MPA s. Meanwhile, area‐focused protection targets have spurred recent and rapid gains in the creation of large MPA s, many of which carry vague objectives set by a diverse group of stakeholders with potentially different notions of “...

The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN R...