Seine nets (also known as ring, or round, nets) are used to catch sardines, herring, pilchards, salmon, and tuna. The other principal form of surrounding net is the trawl, a bag-shaped net that is dragged by a specialized vessel (trawler) along the bottom of the sea or in midwater.
A trawl is a large net, conical in shape, designed to be towed along the sea bottom. The trawl is pulled through the water by one or more boats, called trawlers or draggers. The activity of pulling the trawl through the water is called trawling or dragging.
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