In Asia . Fish farms are dangerous in themselves because diseases spread from the farmed fish and affedt the wild fish. Coral reefs are like the rainforests of the sea, supporting many fish. This slogan made Greenpeace, an international environmental organisation, famous, and it still applies. Whales, dolphins and many big sea mammals have been hunted to the point of extinction.
Most countries use the sea as a sewer.
For example, coastal cities in Africa dump hundreds of millions of litres of sewage and industrial waste into the sea a year. This will continue as they cannot afford sewage treatment plants. As sewage, fertilisers and other . In the past, the Soviets dumped nuclear waste in the shallow seas of the Arctic circle. As these began to leak, the marine life came under threat.