Marine mammals and sonar concern, but very little definitive information was known. In 1995 a comprehensive book on the relation between marine mammals and noise had been published, and it did not even mention strandings. In 2013, research showed beaked whales were highly sensitive to mid-frequency active sonar. Blue whales have also been shown to flee from the source of mid-frequency sonar, while naval use of mid- and high- frequency side-scan sonar was deemed 'the most probable cause' of a mass stranding of around 50 short-beaked common dolphin ("Delphinus delphis") on 9 June 2008 in Falmouth Bay, Cornwall, UK. There was anecdotal evidence from
Hydrus (legendary creature) Hydrus (legendary creature) The Hydrus (also known as "Enhydros, Enidros, Hildris, Hydra, Idra, Idres, Ydre, Ydris", and "Ydrus") is a creature from Medieval bestiaries. They were said to be found in the Nile River. While in the Nile, a crocodile would roll the hydrus in the mud before eating the smaller creature. However, once inside the crocodile's stomach, the hydrus would burst free from the stomach lining. In medieval Christian tradition, this bursting free from the crocodile became an emblem of the resurrection of Christ bursting free from Hell. There is considerable confusion in applying the name hydrus and its