Ecological erosion and expanding extinction risk of sharks and rays

Thanks largely to Hollywood portrayals, many people view sharks as a dangerous threat or a tough, voracious predator. Sharks and other elasmobranchs in fact fill many different niches and play important ecological roles across ecosystems. Furthermore, although they are tough in many ways, they have mostly not been able to hold up to intense pressure from humans. Dulvy et al. looked across 50 years of data and found that total shark and ray abundance has declined by half since 1970, and these declines have led to a loss of key ecological functions across marine ecosystems. —Sacha Vignieri