Traps are used to catch lobsters, crabs, and fish that live along the seafloor. Fish and crustaceans are lured into enclosures that are made of wood and wire, and then find that their escape is blocked. They are often connected to a network of lines and buoys, up to hundreds at a time, and left to sink up to a mile deep before being retrieved days later. Traps are less detrimental when they are fitted with trap doors that allow young individuals to escape. However, pots and traps may threaten animals outside of the cage itself. The lines used to mark the gear at the surface can entangle and kill passing marine mammals and sea turtles. Large whales, such as humpbacks and the endangered North Atlantic right whale can trail gear for hundreds of miles and then be susceptible to exhaustion or infections from the lacerations.
Dredges are mechanized rakes that scrape the seafloor to unearth burrowing shellfish such as clams, oysters, and scallops. Dredges are steel frames pulled along the seafloor to drive animals out of their hiding places and into the mesh net that follows the dredge. The destructive practice of dredging drastically affects seafloor habitats and completely changes the composition of marine communities. In 2012, the implementation of Turtle Deflector Dredges within the scallop fishery may have reduced sea turtle capture by more than 50 percent by blocking them from the dredge entrance.
Harpoons are considered one of the most responsible and selective fishing methods and are used to catch tuna and swordfish. There is little to no bycatch, which leaves the surrounding marine habitat intact. Harpoon fishermen target fish from the front of a boat and sometimes work with spotter planes to find fish. Some fisheries, such as the California drift gillnet fishery that targets swordfish and thresher sharks, should transition to cleaner gear types such as harpoons to improve their fishing efficiency and have a smaller impact on the oceans.