An otter trawl is a cone-shaped net with lateral wings extending forward from the opening, kept open horizontally by two “otter boards.” Fish are directed to a finer-mesh cone of net called the “cod end.”
Bottom trawls catch fish that live close to the sea floor, such as groundfish, and mid-water trawls catch fish that spend time up in the water column (“pelagic” fish), such as herring. Pair trawls use two vessels to tow a net.
A long wall of netting hanging from a floating line, with a weighted line along the bottom. A purse seiner circles the line and draws in the bottom line through rings, “pursing” the bottom of the net closed and thus capturing schools of fish near the water surface.
Mesh of monofilament twine of varied lengths and mesh sizes, stretched with weights across bottom water or with floats across surface waters. Drift gillnets are not anchored to the bottom and are free-floating on both ends or free-flowing at one end and attached to the vessel at the other end.