Executive order targets invasive species blamed for altering ecosystems The White House issued an executive order in November to prevent and control the spread of invasive species, which scientists say are causing fundamental changes in some ecosystems. Both environmentalists and agricultural industry representatives have expressed support for control initiatives. Invasive species are the second leading threat to endangered species, said William Brown, science adviser to Interior Secretary Bruce Babbitt. Cornell University biologist David Pimentel has estimated that alien species cost $123 billion per year in prevention, control, and loss of resources. The federal action was triggered last year by a letter to Vice President Al Gore from 500 scientists, who highlighted the economic and environmental costs of alien invasive species Brown said. The new directive creates a national council of key federal
agencies to develop an invasive species management plan. One of the council's first activities will be to review existing laws and recommend ways to strengthen and better coordinate them. The environmental costs of invasive species are as staggering as their economic costs, Brown said. Alien species are the second greatest threat to biodiversity in the United States, after habitat destruction, according to a new study by David Wilcove, senior ecologist at the Environmental Defense Fund. Wilcove and his colleagues examined data on 1880 threatened plants and animals and found that 49% were imperiled by competition with or predation bv alien species The Office of Technology Assessment conservatively estimates that at least 4500 alien species are now resident in the United States. Wilcove said their cumulative
numbers continue to increase over time, posing "a very significant threat to native plants and animals." According to Wilcove, nonnative weeds have had a heavy impact on range lands, making much of the available forage inedible. The power supply industry also has taken a blow from exotic species such as zebra mussels, which clog freshwater intake valves at facilities, said Wilcove. It now appears as if zebra mussels, which were introduced to the Great Lakes from Europe in ships' ballast water, are fundamentally changing the ecosystems of our freshwater lakes, said Stephen Hamilton, assistant professor at Michigan State University. Hamilton has observed pristine inland lakes in Michigan experiencing large blooms of toxic blue green algae after establishment of zebra mussels. Hamilton is testing a hypothesis that the zebra mussels encourage growth of the toxic algae by eating its competitors JANET PELLEY
EU pushes cogeneration to reduce greenhouse gas emissions The European Union (EU) is pushing electrical and industrial cogeneration—the simultaneous production of usable heat and energy in the same facility—as the primary vehicle with which it expects to meet reductions in carbon dioxide emissions committed to under the Kyoto agreement signed in 1997. Cogeneration currently accounts for 9% of the EU's electricity production, and the EU has set a target of 18% by 2010, estimating that this share will reduce carbon dioxide emissions by 150 million metric tons out of the total 800-million-metric-ton cut required under Kyoto. Traditional cogeneration markets tend to be facilities with a high heat demand such as hospitals, hotels, and industrial sites, particularly the chemical, brewing, food processing, and pulp and paper industries. By recovering much of the waste heat lost in separate electrical generation, overall energy efficiency can be increased up to 85% and beyond
Cogeneration in Europe Cogeneration as a share of power production in EU member states (Courtesy of C0GEN Europe)
DEC 1, 1998/ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 5 3 1 A
