1981: Animals can sometimes make humans look really stupid.
In October, a Soviet submarine ran aground on rocks close to the naval base at Karlskrona in southern Sweden. This was undeniable evidence of foreign intrusion into Swedish territorial waters, and it made Swedes jumpy.
For the next decade, unidentified submarines were frequently reported along the country’s coastline.
The Swedish Royal Navy established sonar contacts and detected the cavitation sounds produced by submarine propellers.
In the 1990s – this is where the animals come in – fresh analysis of underwater noises attributed them to swimming mink, or possibly to shoals of herring releasing bubbles of gas from their anuses.
Source: Ola Tunander, The Secret War against Sweden: US and British Submarine Deception in the 1980s (2004), p. 216