Modern fishing boats include trawlers, such as this commercial shrimp trawler, Miss Mona. After the trawler dredges for shrimp, winches hoist the nets, called trawls, up toward the two horizontal side booms.
Trawlers catch fish by dragging large nets over the seafloor or through the water, then hauling the nets aboard with motorized winches.
The earliest trawlers were sail-powered. Diesel engines power modern trawlers, the largest of which reach 120 m (400 ft) in length. They are usually equipped with facilities for freezing their catch to keep it fresh until they reach shore. Large trawlers can store 8,400 cubic meters (296,600 cubic feet) of frozen fish. Trawlers hunt salmon, shrimp, haddock, and many other types of edible sea-dwelling organisms.