On September 6 a federal judge gave the U.S. Navy the go-ahead to build an undersea warfare training range close to the right whales’ only known calving ground in North Florida. The facility will inundate the surrounding waters with sonar, which has a disastrous effect on whales and other marine mammals.

A mother right whale and her calf swimming off of Amelia Island, Florida. (Photo: FWC Fish and Wildlife Research Institute)

North Atlantic right whales are the most critically endangered species of large whale with only 300 individuals left in the world. This massive species was called the right whale by whalers because they were the “right” whale to kill. Swimming slowly close to shore, they made easy targets.

The Navy’s $100 million facility, designed to train submarines, ships, and aircraft, will span nearly 500 square miles of ocean perilously close to the calving grounds, putting whales and other sea mammals at risk of both ship strikes and sonar.

Hunting of the right whale ceased in the 1930s following the Convention for the Regulation of Whaling, the predecessor to today’s International Whaling Commission. By then it was almost too late–the right whale population was already decimated, and things haven’t improved since. Like other large mammals, right whales are slow breeders. Females do not reach sexual maturity until they are about nine years old, and they only breed every three years.

Though the threat of whaling has passed, right whales are still in terrible danger of being struck by ships or entangled in their fishing gear. In 2010 alone there were five right whales perilously entangled in fishing gear. Two did not survive.

Right whales spend much of the year in the waters off of Nova Scotia, near the Bay of Fundy, feeding on plankton. As winter arrives they migrate south along the coast to give birth to their calves in the warm waters off of southern Georgia and northern Florida. The small patch of ocean is the only known calving area for right whales.

Right whales are especially vulnerable to fatal collisions with ships because of their dark color and lack of a dorsal fin. The danger increases for calving mothers, who spend a lot of time near the surface as they give birth and as their young develop the lung capacity to dive deeper. Currently, the Navy’s only way to avoid ship strikes is by visual detection, which does not bode well for the fate of nearby whales.

Just as menacing is the threat of sonar which can be deadly for ocean mammals. Sound travels through water much faster than air, and can be deafening to marine mammals miles from the source. Loud blasts of sonar often cause whales to surface quickly, and the rapid change in pressure can lead to bleeding from the ears and eyes.

Naval sonar has been linked to multiple marine mammal deaths, notably the stranding of whales and dolphins in the Bahamas in 2000. Examinations of the stranded animals revealed internal hemorrhaging and bleeding in their ears and brains. Another stranding occurred in North Carolina’s Outer Banks in 2005, when 34 whales beached shortly after Navy sonar training. Similar problems have been reported with Orcas in Puget Sound off the coast of Washington.

Sonar can also disrupt normal whale activity like navigation or feeding, cause panic and disorientation. Even whale watching boats can cause hearing trouble and make it hard for whales to communicate.

The Navy’s refusal to give the baby whales a fighting chance by restricting sonar use during the calving season is outrageously typical of the military when it comes to environmental problems. It’s not hard to see how this court decision will likely spell disaster for right whales.

Source: Justine E. Hausheer, “The Wrong Choice for Endangered Right Whales,” audubon.org.