West Coast

Why Beaked Whales Return To Navy Sonar Range Despite Frequent Disturbance

Using data from underwater robots, scientists have discovered that beaked whales prefer to feed within parts of a Navy sonar test range off Southern California that have dense patches of deep-sea squid.

Their findings, published January 29 in the Journal of Applied Ecology, show that beaked whales need these prey hotspots to survive and that similar patches do not exist in nearby “sonar-free” areas.

For decades, the U.S. Navy has used high-powered sonar during anti-submarine training and testing exercises in various ocean habitats, including the San Nicolas Basin off Southern California. Beaked whales are particularly sensitive to these kinds of military sonars, which sometimes result in mass stranding events. Following legal action from environmental activists related to these risks, the Navy modified some training activities, created “sonar-free” areas, and spent more than a decade and tens of millions of dollars trying to find ways to reduce the harm to beaked whales and other mammals.