By Sharon Young

Scientists recently announced that they believe China's white dolphin (baiji), an ancient species originating more than 20 million years ago, is extinct—the first marine mammal species in more than 50 years to be called extinct. The announcement highlights the need for a renewed commitment to saving the many other imperiled species around the world.

China's busy Yangtze River was the baiji's home. Beset by conflicts with local and commercial fisheries and a living in degraded habitat, the dolphins were in decline for decades. This shy species was nearly blind and relied on echolocation to find food and navigate. Scientists also blame its plight on increasing ship traffic and noise in the area that interfered with its ability to hear key biological sounds.

Another Yangtze River dweller, the Chinese finless porpoise, is also at grave risk of extinction. Only 700 individuals remain. Chinese scientists have stated that this is the same situation in which baiji found themselves a mere 20 years ago.

The loss of the baiji urgently underscores the need to help the many other species around the world that are imperiled,including:

• Harbor Porpoise in the Baltic Sea. These small, shy animals are caught in commercial gillnets and their populations in the Baltic and Black Seas may be as low as 600 animals.
  
• Vaquita in Mexico. This is the smallest harbor porpoise. While gillnets catch thousands of harbor porpoises worldwide, the situation for vaquita is particularly grim, as it is estimated that there are fewer than 500 remaining.
  
• North Atlantic Right Whales on the East Coast of the U.S. These large whales faced the heaviest pressure from early whalers. Although the population began to recover, it has been declining again since the 1990's because of entanglement in commercial gillnets and lobster gear and in collisions with large ships. Less than 350 right whales remain.
  
• Maui's Dolphins in New Zealand. There are only approximately 100 of these dolphins remaining and they continue to be caught in commercial fishing nets.
  
• Irawaddy Dolphins in the Philippines. There are only approximately 70 remaining and they too are caught by commercial fisheries.

Some species continue to be exploited despite limited knowledge on their status:

• Fishermen in Japan kill up to 20,000 dolphins and small whales annually, many in drive hunts. A coalition of scientists and zoo professionals have called for an end to these hunts because they threaten the conservation status of wild dolphin populations.
  
• Even though fin whales are endangered, Iceland started hunting them in October 2006. The population of fin whales has declined by at least 50 percent over the last three generations.    
  
• In the Eastern Tropical Pacific Ocean, dolphins are chased and encircled with purse seine nets as a method of catching the tuna swimming beneath, killing up to 5,000 dolphins annually.

Sharon Young is the Marine Issues field director for The Humane Society of the United States.