Rise and Fall of Right Whales
Endangered right whales are unexpectedly bouyant in water
Endangered right whales may be too buoyant for their own good. Biologists in Massachusetts recently learned that the 60-ton mammals can rise to the surface from great depths without swimming. The researchers, from the Woods Hole Oceanographic Institution, attached tags to several North Atlantic right whales and recorded information about their dives. They found that the animals float to the surface from as deep as 250 feet. Most other marine mammals, in contrast, lose buoyancy on dives as water pressure collapses their lungs and pushes air out. This floating ability, probably due to the creature's blubber, may be a problem for right whales. Collisions with ships and entanglement in fishing gear are major causes of death for the species. With less than 300 of the animals remaining in the North Atlantic, experts say the population's prospects are sinking.