ANAHEIM, CALIF. -- A few bad actors among the more than 30,000 non-indigenous species in the United States cost $123 billion a year in economic losses, Cornell University ecologists estimate.
"It doesn't take many trouble-makers to cause tremendous damage," Cornell University ecologist David Pimentel says of a list that runs from alien weeds (cost: $35.5 billion) and introduced insects ($20 billion) to human disease-causing organisms ($6.5 billion) and even the mongoose ($50 million). (See accompanying list, "25 Unwelcome Visitors.") Aside from the economic costs, he adds, more than 40 percent of species on the U.S. Department of the Interior's endangered or threatened species lists are at risk primarily because of non-indigenous species.
Pimentel, who presented his findings today (Jan. 24, 1999) at the annual meeting of the American Association for the Advancement of Science (AAAS) in Anaheim, Calif., noted, however, that "most introduced species of plants, animals and microorganisms have become widely accepted and even beneficial participants in our lives."
The damage report, "Environmental and Economic Costs Associated with Non-indigenous Species in the United States" by Pimentel, a professor in Cornell's College of Agriculture and Life Sciences, and by Cornell graduate students Lori Lach, Rodolfo Zuniga and Doug Morrison, was presented in a AAAS session on environmental science and philosophy. The researchers also acknowledged that 98 percent of the U.S. food supply comes from such introduced species as wheat, rice, domestic cattle and poultry with a value of more than $500 billion a year.
However, even the introduced food sources have alien enemies, such as the
mongoose, that was brought to Puerto Rico and Hawaii in the late 1800s,
supposedly to kill rats in sugarcane plantations. The islands still have rats,
but the mongooses are preying on native ground-nesting birds and on amphibians
and reptiles that could, themselves, be ben
Contact: Roger Segelken
Cornell University News Service