Damselfish on Coral Reef

Damselfish on Coral Reef

Photograph by Paul Sutherland, National Geographic

Coral reefs teem with fish. Some are plankton eaters, others feed on corals, and “grazers” devour ocean vegetation like algae. Larger predators, like snappers and sharks, always stand at the ready to feast on smaller fish.

When humans overharvest reef fish species, the impact can be significant. The loss of “grazers,” for example, can cause algae populations to explode and spur bacteria growth that compromises coral health.