Grimsby is strongly linked with the sea fishing industry, which once generated wealth for the town. At its peak in the 1950s, it was the largest and busiest fishing port in the world. As a result of the Cod Wars with Iceland, this industry has been in decline for many years. In 1970 around 400 trawlers were based in the port, by 2013 only 5 trawlers remain based there. By comparison, 15 vessels are used to maintain offshore wind farms in the North Sea. The town still has the largest fish market in the UK, but most of what is sold
Fishing in the North Sea the 19th century large quantities of herring were produced in Scotland. Today mainly mackerel, Atlantic cod, whiting, coalfish, European plaice, and sole are caught. In addition, common shrimp, lobster, and crab, along with a variety of shellfish are harvested. In recent decades, overfishing has left many fisheries unproductive, disturbing the marine food chain dynamics and costing jobs in the fishing industry. Herring, cod and plaice fisheries may soon face the same plight as mackerel fishing which ceased in the 1970s due to overfishing. Since the 1960s, various regulations have attempted to protect the stocks of fish such as limited fishing