Trawling is a type of fishing in which a trawl is actively dragged or pulled through the water behind one or more trawlers. Trawls are fishing nets that are dragged along the seafloor or in midwater at a specific depth. The word comes from the Dutch term "trawl", which means "a large net used for fishing". Trawls were originally used to catch herring and other groundfish off the coast of Norway. Modern trawlers still use this method to catch fish on the floor of the ocean, but they also catch shrimp, squid, and other marine organisms as well. These days, trawling is done mostly by countries that have oil resources, such as Norway, Russia, and Canada. But even these countries have moved away from using trawlers to catch seafood because of the impact it has on marine ecosystems. Instead, they now hire fishermen who use hook and line or circle hooks to catch fish. The world's largest trawler is the Prirazlomnaya, which is operated by the Russian company Murmansk Trawler Co. It was built in Japan in 1991 and can hold up to 100,000 tons. This makes it larger than most fisheries worldwide. The second largest trawler is the Ekolist FV, which is operated by the Finnish company Greenland Sea Fisheries.