Conservation successes and challenges for wide-ranging sharks and rays

Abstract

Overfishing is the most significant threat facing sharks and rays. Given the growth in consumption of seafood, combined with the compounding effects of habitat loss, climate change, and pollution, there is a need to identify recovery paths, particularly in poorly managed and poorly monitored fisheries. Here, we document conservation through fisheries management success for 11 coastal sharks in US waters by comparing population trends through a Bayesian state-space model before and after the implementation of the 1993 Fisheries Management Plan for Sharks. We took advantage of the spatial and temporal gradients in fishing exposure and fisheries management in the Western Atlantic to analyze the effect on the Red List status of all 26 wide-ranging coastal sharks and rays. We show that extinction risk was greater where fishing pressure was higher, but this was offset by the strength of management engagement (indicated by strength of National and Regional Plan of Action for sharks and rays). The regional Red List Index (which tracks changes in extinction risk through time) declined in all regions until the 1980s but then improved in the North and Central Atlantic such that the average extinction risk is currently half that in the Southwest. Many sharks and rays are wide ranging, and successful fisheries management in one country can be undone by poorly regulated or unregulated fishing elsewhere. Our study underscores that well-enforced, science-based management of carefully monitored fisheries can achieve conservation success, even for slow-growing species.

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems

“…Conceptually, while MPAs could be considered the "treatment" or "control" in our analyses (i.e., fishing is considered either the experiment or the control), we take a social-ecological system perspective and consider human activities, including fishing, to be integral system components (Kandel et al, 2022). Thus, in our analytical framework, MPAs are considered the experimental treatment where fishing is removed (e.g., Pacoureau et al, 2023).…”

High overexploitation risk due to management shortfall in highly traded requiem sharks

“…Globally widespread species of sharks are subject to fragmented management, requiring a coherent response (Dulvy et al., 2017). The wide‐ranging requiem sharks suffer from a patchwork of management and might have lower extinction risk only if a significant part of their range lies within the waters of better managed countries like the United States (Pacoureau et al., 2023). For example, Dusky Shark ( C. obscurus ) is well‐managed in the United States and Australia, but less so elsewhere in its range (Figures 1 and 2).…”

Emerging human–shark conflicts in the New York Bight: A call for expansive science and management

“…Population declines of sharks and their relatives have been well documented over the last several decades on a global scale—primarily attributed to targeted fishing and by‐catch by commercial and recreational fisheries (Baum et al, 2003; Dulvy et al, 2014, 2021). In the United States, federal and state management actions such as catch quotas, closed seasons, gear restrictions, and species prohibitions aim to sustainably manage shark populations (Pacoureau et al, 2023; Shiffman & Hueter, 2017; Simpfendorfer & Dulvy, 2017). These measures may have been adequate to support initial recovery for some species (Pacoureau et al, 2023; Peterson et al, 2017).…”

“…In the United States, federal and state management actions such as catch quotas, closed seasons, gear restrictions, and species prohibitions aim to sustainably manage shark populations (Pacoureau et al, 2023; Shiffman & Hueter, 2017; Simpfendorfer & Dulvy, 2017). These measures may have been adequate to support initial recovery for some species (Pacoureau et al, 2023; Peterson et al, 2017). However, for others, current management efforts have proven unsuccessful (Sherman et al, 2023), or their effectiveness remains unknown (Barker & Schluessel, 2005; Dulvy et al, 2017).…”

“…Further, not all species present in the New York Bight are likely to be responsible for a NHSI. Therefore, statements generalizing that “sharks” have increased in abundance, while true for some species (Pacoureau et al, 2023), provide platitudes for media outlets, do not inform the public, and are contextually inaccurate. Further, this conjecture places blame on species that are not responsible for NHSIs, further increasing conservation risk for all species.…”