<p class="MsoNormal">Doomed by a gill net, a thresher shark in Mexico's Gulf of California is among an estimated 40 million sharks killed yearly for their fins. Removing top predators, such as sharks and bluefin tuna, from the ecosystem can degrade marine habitats.</p>

Trapped Thresher Shark

Doomed by a gill net, a thresher shark in Mexico's Gulf of California is among an estimated 40 million sharks killed yearly for their fins. Removing top predators, such as sharks and bluefin tuna, from the ecosystem can degrade marine habitats.

Photograph by Brian J. Skerry

Ocean Habitat Destruction

See photos of examples of ocean habitat destruction (such as bleached coral, bottom trawlers, and more) in this photo gallery from National Geographic.

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