Significant numbers of sharks — including blue and mako — have perished as “by-catch” in commercial tuna and swordfish operations in recent decades. Collapsing shark populations already have severely disrupted the food chain of at least two coastal marine ecosystems – along the east coast of the United States and in the Gulf of Mexico. In the high seas, there could be even more severe consequences because the shark is a top predator, marine biologists say.
Sharks are prized for their meat and, in Asia, especially for their fins, a prestige food thought to convey health benefits. They are especially vulnerable to overfishing because most species take many years to mature and produce relatively few young.
The soaring value of shark meat has prompted some tuna and swordfish fisheries to target them as a lucrative sideline, said Sonja Forham, policy director for the Shark Alliance. She is a co-author of the IUCN study, which surveyed 64 species of open water , or pelagic, sharks.
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