What kind of ships to the deep-sea fishermen take?

The deep-sea fishermen go fishing on trawler, which can be easily identified by their unique masts and bridge-like structures. The fishermen fix their nets on the trawlers before casting them in the water and then haul up the catch with the help of ropes. Unlike the coastal fishermen, the deep-sea fishermen travel far into the open sea to catch fish and often stay there for up 60 days. To prevent the fish form spoiling, it is processed in the sea itself and kept in big freezers, Animals rights activists and environmentalists often allege that fishermen do not spare even endangered sea creatures such as dolphins and whales. Many species of fish, like the codfish, are now on the verge of extinction owing to large-scale deep-sea fishing.