To the list of humans assaults on our marine environment from giant garbage islands to over-fishing, add one that you can't see: noise pollution.

US scientists led by Anne Simonis at the Pacific Islands Fisheries Science Centrehave identified a "strong association" between strandings of rare whale species and the use of sonar in anti-submarine warfare exercises.

A Blainsville's beaked whale, photographed in Guam, a US territory in Pacific. Credit:Adam U/NOAA

The researchers focused on beaked whales, a relatively little studied group of cetaceans that emit signals to "echolocate" prey and to navigate in their dives into dark ocean depths as deep as almost 3 kilometres.

Navies began introducing so-called mid-frequency active sonar from the early 1960s. Since then, researchers have recorded at least 12 mass stranding events involving two or more beaked whales that coincided with naval exercises, and 27 others near a naval base or ship, according to work published by The Royal Society.