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Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas.sup.1-3. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goals.sup.4,5: the Living Planet Index (a measure of changes in abundance aggregated from 57 abundance time-series datasets for 18 oceanic shark and ray species) and the Red List Index (a measure of change in extinction risk calculated for all 31 oceanic species of sharks and rays). We find that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fishing pressure. This depletion has increased the global extinction risk to the point at which three-quarters of the species comprising this functionally important assemblage are threatened with extinction. Strict prohibitions and precautionary science-based catch limits are urgently needed to avert population collapse.sup.6,7, avoid the disruption of ecological functions and promote species recovery.sup.8,9. The global abundance of oceanic sharks and rays has decreased by 71% since 1970 and 24 species are threatened with extinction owing to a concomitant increase in fishing pressure., Author(s): Nathan Pacoureau [sup.1] , Cassandra L. Rigby [sup.2] , Peter M. Kyne [sup.3] , Richard B. Sherley [sup.4] , Henning Winker [sup.5] [sup.6] , John K. Carlson [sup.7] , [...]

The National Marine Fisheries Service (NMFS) began placing at-sea observers on commercial shrimping (Penaeidae and Sicyonia brevirostris) vessels in the early 1990's in the southeastern region of the United States (U.S.) to identify and minimize the impacts of shrimp trawling on federally managed species. Recent analysis of bycatch data relative to smalltooth sawfish, Pristis pectinata, a species endangered globally, indicated a high level of uncertainty in the estimated take in the U.S. Due to costs associated with observer coverage, and given the rare event of capturing a smalltooth sawfish, increasing observer coverage to refine take estimates of this species is not considered practical. We explored the use of electronic monitoring (EM) to provide a valid alternative to increased observer coverage for the purpose of documenting fishery interactions with smalltooth sawfish. This system was additionally used to document interactions with other protected species and large teleost and elasmobranch bycatches (>1.0 kg). While no smalltooth sawfish were observed, the catch and safe release of a loggerhead sea turtle, Caretta caretta, was recorded by both the EM system and observer. The EM system was used to record commercial shrimp vessel operations during six trips, encompassing 1,733 h of video over 94 sea days, with a certified fishery observer also being present for the full duration of each trip. Catch composition documented by the EM reviewer was compared to observer data. Overall, 20 tows contained a total of 33 bycatch items in the observer sample that met criteria of being over 1.0 kg. Of these catch items, 87.9% were also detected by the EM reviewer compared to observer data. Detection rates for elasmobranchs were higher in comparison to teleosts, at 95.8%. Pairwise comparison of EM video to data collected by onboard observers (animals >1.0 kg in size) lead us to conclude that EM would be an effective tool for detecting protected resources and larger fauna interactions in the Gulf of Mexico shrimp trawl fishery., Introduction The use of electronic monitoring (EM) has the potential to augment the collection of bycatch information and lessen the need for onboard scientific observers, which in some cases can [...]

Abstract--Preliminary validation of annual growth band deposition in vertebrae of great hammerhead shark (Sphyrna mokarran) was conducted by using bomb radiocarbon analysis. Adult specimens (n=2) were collected and thin sections [...]

ABSTRACT--Night sharks, Carcharhinus signatus, are an oceanic species generally occurring in outer continental shelf waters in the western North Atlantic Ocean including the Caribbean Sea and Gulf of Mexico. Although [...]

Abstract--The age and growth dynamics of the spinner shark (Carcharhinus brevipinna) in the northwest Atlantic Ocean off the southeast United States and in the Gulf of Mexico were examined and [...]

Abstract--The life history and population dynamics of the finetooth shark (Carcharhinus isodon) in the northeastern Gulf of Mexico were studied by determining age, growth, size-at-maturity, natural mortality, productivity, and elasticity [...]