Abstract | Extinction risk and conservation of the world’s sharks and rays

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Extinction risk and conservation of the world’s sharks and rays

Abstract

Affiliation details

Simon Fraser University, Canada; NatureBureau International, United Kingdom; College of William and Mary, United States; British Antarctic Survey, Natural Environment Research Council, United Kingdom; Charles Darwin University, Australia; NOAA/National Marine Fisheries Service, United States; The Ocean Foundation, United States; National Institute of Water and Atmospheric Research, New Zealand; International Union for the Conservation of Nature, United Kingdom; James Cook University, Australia; University of Florida, United States; Old Dominion University, United States; South African Museum, South Africa; Moss Landing Marine Laboratories, United States; Australian Institute of Marine Science, Australia; Conservation International, United States; Commonwealth Scientific and Industrial Research Organisation, Australia

The rapid expansion of human activities threatens ocean-wide biodiversity. Numerous marine animal populations have declined, yet it remains unclear whether these trends are symptomatic of a chronic accumulation of global marine extinction risk. We present the first systematic analysis of threat for a globally distributed lineage of 1,041 chondrichthyan fishes—sharks, rays, and chimaeras. We estimate that one-quarter are threatened according to IUCN Red List criteria due to overfishing (targeted and incidental). Large-bodied, shallow-water species are at greatest risk and five out of the seven most threatened families are rays. Overall chondrichthyan extinction risk is substantially higher than for most other vertebrates, and only one-third of species are considered safe. Population depletion has occurred throughout the world’s ice-free waters, but is particularly prevalent in the Indo-Pacific Biodiversity Triangle and Mediterranean Sea. Improved management of fisheries and trade is urgently needed to avoid extinctions and promote population recovery.

DOI: http://dx.doi.org/10.7554/eLife.00590.001