Collapse and Conservation of Shark Populations in the Northwest Atlantic

TLDR

Overexploitation threatens many large vertebrates, and while tunas and sea turtles are already conservation concerns, the status of most shark species remains uncertain. The study aims to use closed‑area models to identify priority areas for shark conservation and to evaluate how effort reallocation and site selection can benefit multiple threatened species. The authors applied closed‑area modeling to highlight conservation priority zones and assess the impact of reallocating fishing effort and selecting reserve sites. Analysis of the largest Northwest Atlantic shark dataset reveals rapid declines, with scalloped hammerhead, white, and thresher sharks each dropping more than 75 % over the past 15 years.

Abstract

Overexploitation threatens the future of many large vertebrates. In the ocean, tunas and sea turtles are current conservation concerns because of this intense pressure. The status of most shark species, in contrast, remains uncertain. Using the largest data set in the Northwest Atlantic, we show rapid large declines in large coastal and oceanic shark populations. Scalloped hammerhead, white, and thresher sharks are each estimated to have declined by over 75% in the past 15 years. Closed-area models highlight priority areas for shark conservation, and the need to consider effort reallocation and site selection if marine reserves are to benefit multiple threatened species.