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
Blue cod change. Since a number of evidence indicated that blue cod are relatively sedentary, the fishing pressure may lead to potential local depletion. Recent studies showed that the genetic differences were significant between mainland List of islands of New Zealand population and Chatham Island population. On the other hand, the differences within mainlandList of islands of New Zealand populations were limited while the pattern of the isolation by distance was detected. Further research using microsatellite DNA markers suggested that some significant genetic differences between mainland population exist which indicate the potential long-distance dispersal, but the dispersal rate is too low to