Doomwatch (U.S. title: Island of the Ghouls) is a 1972 British science fiction film directed by Peter Sasdy and starring Ian Bannen, Judy Geeson and John Paul. Described as both a thriller and a horror film, it is based on the BBC television series Doomwatch (1970–1972). The screenplay was written by Clive Exton. In the United States it was released by Embassy Pictures.
Waters surrounding an island become contaminated by chemical dumping, and people who eat fish caught in those waters become deformed and violent.
An outsider visits a remote isolated village that has seemingly shunned modern life. Dr. Del Shaw, an investigator from the British ecological watchdog group nicknamed Doomwatch, is sent to the island of Balfe to file a report on the effects of a recent oil tanker spillage. He becomes fascinated with the mysterious behavioural disorders of the locals who display rudeness and random aggression and a strange genetic prevalence of thick lips and sloping brows. Investigation shows that the villagers have been suffering over a prolonged period from hormonal disorders, which are being caused by leaking drums of growth stimulants that have been dumped offshore. The islanders have been eating contaminated fish and develop a disorder of excessive hormonal growth, which produces aggression and eventually madness, attributed to a form of acromegaly. Rather than seek help from the mainland, they hide those who are deformed from any newcomers.