When doing industrial fishing, people want to catch certain species of fish. When they are using nets, they will also catch other species. These are called bycatch or by-catch. Most of the time, the animals caught will be severely injured or killed. Most of these species are thrown back into ithe sea, but some of the bycatch is used. The exact amount of bycatch is not known. There are estimates that up to a quarter of the total may be bycatch. When catching shrimp, up to eighty percent may be bycatch. Another problem is that the amount of bycatch is not recorded, and does not show up in statistics.