The Essex Naturalist
53
During the 20th century there has been a large decline in the number of
cetaceans in the North Sea. During the first 50 years the large whales were
hunted, in some cases, almost to extinction, after which whaling pressure was
applied to smaller species such as minke, northern bottlenose and pilot whales.
In 1986 a ban on the hunting of all species was introduced by the International
Whaling Commission; however, Norway continues to take minke whales and
pilot whales are exploited by Faroe Islanders.
Fig. 3. Strandings along Essex coast for each decade between 1912-1997
Cetaceans have been stranded in all months with peaks in April (ten of the
records were of porpoises) and September. The decline during the winter
months is due to the reduced effort on the part of observers and the movement
of cetaceans from colder waters. The decline of smaller cetaceans, particularly
coastal species such as the porpoise and bottle-nosed dolphin has been due to
less direct action by man. The discharge of pollutants into the North Sea by
industrialised countries and the decimation of fish stocks, particularly the