Otter trawlers are fishing vessels that use a type of net called an otter trawl to catch fish and other marine life. The net is designed with two large, weighted doors that open the net as it is dragged along the seabed. This method allows for the capture of a wide variety of species, including cod, shrimp, and flounder. These trawlers are typically equipped with powerful engines and advanced technology to locate fish. While effective for harvesting seafood, otter trawling can also raise concerns about bycatch, which refers to the unintended capture of non-target species, and the impact on marine ecosystems.