Another issue affecting the health of the oceans is bycatch, when fishing gear unintentionally catches species such as seabirds, sea turtles and other marine life. They are ultimately thrown overboard, dead or dying, because they have no market value or are prohibited to sell. Approximately 25% of the world's catch is wasted; 44 billion pounds of marine life a year are bycatch.

The shrimp trawler above tows a net through the water, catching everything in its path. Worldwide, estimates assert that for every single pound of shrimp trawled, between two and 10 pounds of unwanted marine life are caught and discarded overboard, dead or dying. This ratio varies from fishery to fishery. Shrimp bycatch also includes endangered sea turtles. Shrimp fishermen in the U.S., however, have incorporated Turtle Excluder Devices (TEDs) and other bycatch reduction gear, allowing sea turtles and other marine life to escape from nets while still in the water.