Earth Talk - Little is known of hard-to-track orcas
Orcas are very susceptible to pollution, due to their place at the top of the ocean food chain. But little is known of their habits since they're hard to track.
Q: How are populations of the world’s orca whales faring these days?
– J. Witham, Bangor, Maine
A: The largest member of the dolphin family and a major draw at marine parks, orcas (also known as “killer whales”) are highly intelligent and social marine mammals. Many of their habits are still a mystery to science, as the great black-and-white creatures, which can grow to 26 feet and weigh six tons, are fast-moving and difficult to track.
Given this uncertainty, the International Union for the Conservation of Nature (IUCN), a nonprofit group that maintains a frequently updated global list (the so-called Red List) of endangered and threatened wildlife, merely lists the status of orcas as “data deficient.” IUCN is currently involved in an assessment of orca populations around the world to determine what their status should be.
Orcas may not have a clear-cut conservation status internationally, but the US government is concerned enough about the animals that ply the waters of Washington’s Puget Sound and San Juan Islands to put them on the federal endangered species list. Chief among threats to orcas is loss of their food supply, mostly West Coast salmon populations destroyed by hydroelectric dams and other human encroachment. Habitat loss, chemical pollution, captures for marine mammal parks, and conflicts with fisheries have also played roles in the decline of the Northwest’s orcas.