Echo from the end of a dolphin species
The baiji, a freshwater dolphin, has used sonar to find fish in China's Yangtze River for some 20 million years. Last week, scientists declared it basically extinct. Can the end of a nearly blind cetacean help humans see the need for greater species conservation?
Five events in Earth's history have caused extinction waves, including the asteroid thought to have slammed into the Yucatán and ended the dinosaur age. Whether the planet is on the verge of a sixth wave of extinctions, or already in it, is a matter of debate, but either way, the situation should be taken seriously.
The World Conservation Union's "Red List" is at an all-time high: 16,119 threatened species (out of 15 million estimated species). This century-old trend is largely human-made and ongoing, with one harbinger being the extinction of many large mammals from North America.
In 1973, the United States responded with the Endangered Species Act, the toughest such protection law in the world. Wolves, bald eagles, and grizzlies have rebounded, and about 85 percent of the 1,322 species on the US endangered list are stable or increasing, the Center for Biological Diversity in Tucson, Ariz., estimates.
Other places in the world are not so conservation-minded. Hot spots include Indonesia, Papua New Guinea, and Brazil, where massive logging and mining are eliminating forest habitat at alarming rates. And "China is dangerously near a crisis point" with its environment, writes Pan Yue, the vice minister of China's State Environmental Protection Administration.