BOSTON — Estimates vary but there are between 75 to 80 whale species in the world's oceans. Most have dwindled to 10 to 20 percent of their pre-hunting populations before widespread commercial whaling took place over three centuries.
Whaling has decreased drastically today, because of strict antihunting regulations in this century. In a landmark event, the International Whaling Commission voted for a moratorium on commercial whaling beginning with the 1985 and 1986 hunting seasons.
Now, only three countries - Norway, Japan, and Iceland - engage in whale hunting. These countries primarily hunt minke whales, which is considered an abundant species. Japan, however, only does what it calls "scientific whaling," for the purpose of collecting scientific data, but many of the whales caught are sold for commercial purposes and consumption. (Inuits from Greenland, Canada, and Alaska also hunt a small number of beluga and bowhead whales.)
Major threats facing whales:
Pollution. Chlorine from pesticides and PCBs from the electronics industry wash into waterways and oceans, eventually causing reproductive problems.
Less physical space. Whales are threatened when their living space is taken over by vessel traffic, development, damming, and irrigation projects. Loss of calving grounds has been a problem. In Mexico, a proposed saltworks plant in Baja California will require the construction of dams. But the operation will drive away gray whales from their calving areas off the coast.
"The places that whales go to breed, eat, and live in are being absorbed by human uses," says Michael Williamson, creator of WhaleNet, a Web site about whales.
Entanglements and ship strikes. Entanglements in fishing gear are a common problem for dolphins and porpoises (considered whales). Right and, occasionally, humpback whales are prone to strikes by large vessels. "We need to create an awareness in the shipping industry for these whales," says Nina Young, marine-mammal research scientist for the Center for Marine Conservation in Washington.
Most endangered whales:
Right whales. Their population hasn't recovered since hunting for them ended in approximately 1860. Slow swimmers that yield a large amount of oil, they were so named because they were the "right" whale to hunt. In pre-whaling days, they numbered about 300,000 worldwide; now there are only 300 remaining in North Atlantic and about 4,000 off South America.
Blue whales. Only 5 percent of the original pre-hunted population now exists. These giant animals, the largest to have ever lived on earth, measure approximately 100 feet long and weigh 90 tons. They live in many waters including the Pacific and Atlantic Oceans and the Gulf of St. Lawrence. Their numbers reached about 226,000 in pre-whaling days, but now only about 15,000 remain. The mammals are making a comeback in some regions off the California coast, but in areas around Antarctica, the population isn't increasing as much.