How Consumers Affect Biodiversity

A display in my local natural foods store stops me cold: Alongside products labeled "Not Tested on Animals" stand bottles of ground shark cartilage, and a book, Sharks Don't Get Cancer. While many studies have overwhelmingly discredited shark cartilage as a cancer therapy, approximately 50,000 Americans will consume it this year, The Amicus Journal reports. Meanwhile, shark populations have plunged since the 1970s, some species by more than 75%, due to overfishing, spurred in large part by Asia's appetite for shark-fin soup.

Sharks aren't the only dwindling predators prey to humans. "In New York City's Chinatown last summer, I found medicines containing powdered tiger and leopard bones, which are both illegal and endangered, in nine stores," reports Anthony Marr, director of Heal Our Planet Earth Global Environmental Organization. While most Americans may not be consuming poached wild animals, many of our mundane daily choices, from fish to clothing, do impact the viability of many species.

Biodiversity, the variety of life forms on Earth, is in trouble. Worldwide, approximately 34% of fish, 25% of mammals, 11% of birds, 20% of reptiles and 25% of amphibians, are on the World Conservation Union (IUCN) Red List of species threatened with extinction. "Currently, we are driving species to extinction up to 1,000 times faster than the natural rate, which is one in a million per year," says Stuart Pimm, Ph.D., professor of conservation biology at Columbia University in New York.

While it's important to support protective legislation, such as the U.S. Endangered Species Act, and its enforcement, there are two major threats to biodiversity that we as consumers can directly help abate: trade in threatened species, and proliferation of invasive species.

Trade in Threatened Species

"For a long list of threatened animal species out there, trade in their parts is the foremost threat," says Craig Hoover, senior program officer at TRAFFIC North America, a program of the IUCN and the World Wildlife Fund (WWF) that monitors trade in endangered species. Poached tigers, bears, rhinos, leopards and pangolins are used in traditional Chinese medicines sold in North American shops, although this is illegal under the United Nations' Convention on International Trade in Endangered Species (CITES). The hunting of "bushmeat" has surpassed habitat destruction as the number one threat to primates. And most Southeast Asian turtles have vanished into the soup pots of China.

Fueled by demand for ivory jewelry and carvings, elephant killings in Africa rose in 1999. Tortoiseshell combs and jewelry from endangered sea turtles are still sold in some Caribbean countries. The U.S. Department of Commerce has listed 98 species of fish -- a record number -- as harvested beyond sustainable levels. And New York socialites were subpoenaed by a U.S. district court in 1999 for owning shahtoosh shawls, from the wool of poached, endangered Tibetan antelopes called chirus, of which only 75,000 remain.

We can make a positive difference by avoiding such products, and telling others. "Ask exactly what you're purchasing and where it's coming from, and check to make sure it's not threatening wild populations," Hoover says. You can get a list of endangered species from TRAFFIC.

The same goes for plants. "Collection for the herb trade is a large factor in the precarious status of plants such as American ginseng, goldenseal, echinacea, black cohosh, and slippery elm," says Chris Robbins, program officer at TRAFFIC. Although goldenseal is listed as endangered or imperiled in numerous states, only 2.4% of the 260,000 pounds used in 1998 came from cultivated sources. "Consumer awareness is an enormous benefit to addressing these problems," Hoover adds.

Exotic Invaders

As a volunteer at The Nature Conservancy's Ives Road Fen Preserve in Michigan in 1996, I was puzzled to be assigned the task of demolishing every sample of an attractive, healthy bush. The reason soon became clear: My victim, the fast-growing European glossy buckthorn, was shading out and drinking up the water supply of the 150 rare native plants in the ecosystem. Such non-native, invasive species "are one, if not the primary, cause of species extinctions," Dr. Pimm says.

At least 4,500 non-native animals and plants have established populations in the U.S., and approximately 15% have become invasive, harming natives. And the invasions are accelerating. "The amount of both passenger and commercial cargo traffic has increased by about 100% in the past decade, and people and cargo bring things in with them," said Dan Glickman, then U.S. Secretary of Agriculture, in March 2000 in New York City, where he was addressing the emergency of the tree-killing Asian longhorned beetle. Since its discovery in the U.S. in 1996, 5,600 infested trees have had to be chipped and burned in New York and Chicago.

The beetle is believed to have entered the U.S. on wooden packing crates, like many invaders that hitch rides on ships and airplanes. Others are imported as pets or for beneficial purposes, then run amok. Invasive pests cost the U.S. around $138 billion per year, according to a 1999 Cornell University study.

The U.S. Department of Agriculture, responsible for controlling and preventing the entry of invading species, historically helped create the problem. "By 1923 the department had introduced more than 50,000 exotic plants into the U.S." for intended beneficial uses, writes Robert S. Devine in his book, Alien Invasion (National Geographic Society, 1998, $15). Some, such as crabgrass and Johnson grass, became major weeds, and many of the insect pests and plant diseases that now plague farmers snuck in on those thousands of plants. Although regulators have made advances in stopping invasive species at the border, "A whole host of plants that have become invasive pests are still for sale in nurseries," observes Janet Marinelli, director of publishing at the Brooklyn Botanic Garden. By choosing not to buy such invasive plants or products made from threatened species, we may help turn back the species-ravaging tide.