No simple answer to recent amphibian declines Recent major declines in amphibian populations are symptomatic of a general decline in environmental quality and do not have a single obvious cause, concluded scientists at a recent National Science Foundation workshop. Participants at the May conference in Arlington, Va., agreed that frog and salamander declines in pristine wilderness areas are probably caused by a combination of environmental contamination, disease, increased exposure to UV-B light due to the thinning of the stratospheric ozone layer, and global climate change, said workshop organizer Jim Collins of the Arizona State University. Because the scientists suspect these factors are acting simultaneously, and perhaps synergistically, they called on public and private agencies to support an interdisciplinary collaborative research program to identify the causes and mechanisms Over the last 15 years, scientists have documented dramatic losses in amphibians in protected areas such as national parks and conservation reserves, said Bruce Bury, research zoologist with the U.S. Geological Survey (USGS). In
Andy Blaustein of Oregon State University checks field experiments in the Cascade Mountains that have shown that amphibian eggs have a greater success in hatching when they are shielded from UV-B radiation. His theory that UV-B radiation contributes to population declines in amphibians is still controversial. (Courtesy of Oregon State University)
the continental United States, "the number of endemic species that have suffered losses or are suspected of having severe threats has increased from 33 species in 1980 to 52 species in 1994," Bury said. Worldwide, hot spots of decline include the western United States and high-elevation tropical forests in northeast Australia and Central America.
AIR QUALITY Auto industry calls for low-sulfur fuel A smoldering row between the oil and car industries over how to reduce air pollution from motor vehicles has erupted again following the launch of a "worldwide fuel charter" by a coalition of European, Japanese, and American car manufacturers' associations in June. The Association of European Car Manufacturers, ACEA, and its partners seek a new international harmonization of fuel standards for diesel and gasoline. The proposed new standard covers many aspects of fuel formulation, including a target of 30 parts per million sulfur in gasoline. This is just 6% of current levels. According to the car manufacturers, very low sulfur levels are needed to support a new generation of engine and exhaust control technologies. The oil industry has consistently argued that overall emissions from vehicles could be reduced more cost-effectively through other means than very stringent sulfur levels. Also in June, EU environment ministers meeting in Luxembourg agreed to tighten controls on sulfur content of industrial and heating oils. Beginning in 2003, sulfur content of heavy fuel oil, which is used in industry, will be generally limited to 1%. A limit of 0.2% has been agreed for gas oil, used in smaller plants, domestic heating, and some ships. —Reprinted with permission from ENDS Environment Daily, Environments! Data Services, Ltd., London (http://www.ends.co.uk, e-mail
[email protected])
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Scientists are concerned about the mysterious losses in pristine areas, said Collins, "because amphibians are harbingers of general environmental degradation." They are sensitive to climate changes and pollutants thanks to their combined terrestrial and aquatic life cycle, their ability to exchange air and water through their skin, and because their eggs lack a protective shell. As recently as 1990, scientists did not agree that the losses were more than the normal boom and bust fluctuations of amphibian population cycles, said Collins. But as a result of conclusive research on declines since then, the NSF workshop was held to review what is known about the major causes of declines and "determine an appropriate management and policy response," said Collins. The ecologists, toxicologists, and pathologists from the United States, Canada, United Kingdom, and Australia at the workshop reported on a wide range of recent results. USGS researcher Gary Fellers reported on a survey published in 1996 of a transect near Yosemite National Park that had been studied in the early 1900s. Of the seven frog and toad species listed in that survey, at least five have suffered serious declines, he said. Fellers has also surveyed frog and toad species at more than
4000 sites in California, where he has observed that declines are much more substantial downwind of agricultural areas in California's Central Valley. He emphasized that "we don't know the cause of the declines, but herbicide and pesticide use [is] likely." Biologist Karen Lips of St. Lawrence University in New York state presented results published earlier this year that indicate disease could be playing a role in amphibian losses in Costa Rica and Panama. Between 1988 and 1997, she observed a pattern of die-offs that moved north to south through a series of mountain forest preserves. A new analysis of some of the frogs revealed an infection by a chyrid fungus, which has never before been known to infect vertebrates. She hypothesized that environmental stressors such as pollutants or UV-B
radiation, could be weakening the frogs and predisposing them to secondary infections. Biologist Andy Blaustein at Oregon State University spoke of his pioneering field experiments that demonstrate that amphibian eggs shielded from UV-B radiation have greater hatching success than eggs exposed to ambient levels of UV-B radiation. He has also found that when a fungal pathogen and UV-B radiation occur simultaneously, they have a greater negative impact than the sum of their individual impacts. However the theory that UV-B radiation levels are tied to declines remains controversial said Steve Corn a USGS zoologist Corn said he could not replicate Blaustein's results with a similar but different species "A lot of discussion and work remains to be dnnp " he rnncliided
What the researchers did agree on, said USGS research biologist Don Sparling is that the causes of the declines are poorly understood and caused by multiple environmental factors. He said, for instance, that increased levels of UV-B radiation could increase the biotoxicity of pesticides to tadpoles. Global climate change or environmental contaminants could be changing features of the frogs' biotic environment in complex ways that lead to increased susceptibility to disease or pollution added Collins. The federal government appears to be taking the scientist's concerns seriously. Interior Secretary Bruce Babbitt announced at the workshop that he is setting up an interagency task force to coordinate federal research on amphibian declines. —JANET PELLEY
Census Bureau conducts first environmental survey The U.S. Bureau of the Census released its first survey of the environmental industry in June. Though it was applauded for officially defining the industry using government business classifications, some in the industry felt that the survey's value was limited because there were no plans to conduct a follow-up survey. Using 1995 data, the Census Bureau in its "Survey of Environmental Products and Services" valued the industry at $102.8 billion using 1995 data, and credited it with creating 774,000 jobs. Prepared for EPA and the Department of Commerce's International Trade Administration, the survey was funded in 1995 by President Clinton's environmental technology initiative. Funding for that program was not reauthorized after 1996. The survey grouped the industry into eight categories: air treatment ($5.9 billion in product shipments and receipts); water and wastewater treatment ($31.1 billion); solid waste ($35.9 billion); energy conservation ($2.5 billion); noise pollution control ($168 million); monitoring, assessment and analysis ($5.4 million); adminis-
trative, management and engineering ($6.3 million); and other ($15.7 billion). These allocations are comparable to Environmental Business International's annual survey figures, according to EBI president Grant Ferrier, whose 1995 figures pegged the industry at $179 billion. The main reason that the government's industry valuation is lower than EBI's, Ferrier explained, is that the Census survey excluded public utilities. The survey also did not include data for any environmental services performed internally by businesses to reduce or eliminate pollutants Instead, the survey focused on private-sector producers of goods and services, including data from businesses with 49 different "standard industry classification" (SIC) codes. By defining the industry using these codes, which classify businesses on government forms such as income tax statements, the survey makes a "very valuable" contribution, according to Ira Rubenstein cofounder of the new national Environmental Business Coalition {ES&T March 1998 p. .24A)) Because SIC code designations
are based on a business's primary activity, they often do not adequately reflect the full spectrum of its products—or their uses— explained Elinor Champion, chief of the Bureau of the Census' Special Studies Branch. For example, she said, one SIC category includes "laboratory and analytical instruments." Some, but not all of these instruments may be used in the environmental industry. Though Ferrier agreed that associating a group of SIC codes with the industry was important, he also criticized the survey's reliance on these codes as a "piecemeal" approach. SIC codes obviously include many nonenvironmental businesses, and only one in four of the survey's respondents were actually involved in environmental projects. Ferrier was also disappointed that the survey results did not include the export data that had been collected. An EPA spokesperson confirmed that there were no plans to conduct a follow-up to the survey. Because this will not allow for long-term trend analysis, Ferrier said the survey is "not very useful for the industry." —KELLYN S. BETTS
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