People abuse the coastal marine environment by destroying habitats, by over-fishing and pollution.
Land prices are rising too, forcing change in economic activity and forcing out local fishing villagers. World fish catches peaked in 1987 and are now falling. Because modern fishing techniques suck up too many fish, large and small so there are not enough young fish left to breed. In Asia . Fish farms are dangerous in themselves because diseases spread from the farmed fish and affedt the wild fish.