Bycatch is a term for the unintentional capture of marine animals, typically from larger fisheries that utilize methods that capture a ton of organisms all at once. For instance, a gillnet is a large net that, when fish try to swim through, their gills get caught and they cannot swim away. The purse seine is a huge net that scoops up the fish and closes around them (think of that scene in Finding Nemo). One of the worst is dredging, where a bar with a net attached is dragged along the sea floor, tearing up habitats and capturing anything settled on the bottom. Bycatch is a leading cause of whale, shark, dolphin, and turtle deaths, and is estimated to kill around 40% of fish that's captured. :'( Bycatch is a term for the unintentional capture of marine animals, typically from larger fisheries that utilize methods that capture a ton of organisms all at once. For instance, a gillnet is a large net that, when fish try to swim through, their gills get caught and they cannot swim away. The purse seine is a huge net that scoops up the fish and closes around them (think of that scene in Finding Nemo). One of the worst is dredging, where a bar with a net attached is dragged along the sea floor, tearing up habitats and capturing anything settled on the bottom. Bycatch is a leading cause of whale, shark, dolphin, and turtle deaths, and is estimated to kill around 40% of fish that's captured. :'(