studies for Exxon. "They're making the assumption that any change that they see is somehow linked to the oil spill," Page said. Indeed, NOAA and the Trustee Council admit that other factors such as rising temperatures in ocean waters, the availability of
prey, predation by other species, human fishing pressures, and the loss or degradation of habitat make it difficult to tease out oil spill impacts from natural impacts on species recovery. But with Exxon Valdez oil still out there in western Prince William
Sound, it makes sense that oil is still causing stress to plant and animal species in that region, Wright said. "And it's important to note that the effects we're seeing are occurring in [streams that were oiled], not unoiled ones," he added. —KRIS CHRISTEN
Technology gaps exacerbate vulnerability to heavy oil spills Though February's burning of the oil-laden freighter grounded off the Oregon coast was not a complete success, most observers believe the air pollution it generated was worth the ocean life it saved. The ill-fated ship's plight illustrates key technology gaps that may make vessels transporting heavy fuel more vulnerable and spills harder to clean. A National Research Council (NRC) report due out this spring will address the need for new heavy oil spill cleanup and prevention technologies, said Keith Michel, president of Herbert Engineering, a firm involved in ship design and a member of the NRC's Committee on Marine Transportation of Heavy Oil. Although he refused to comment on specifics, he acknowledged that the report may call for shipdesign modifications to decrease the chance that heavy oils get spilled. According to NRC research, 25% of the petroleum products recently spilled in U.S. waters are heavy oils, which the report's authors define as including asphalts and coal tar, as well as the residual oils increasingly used as power plant fuel. NRC's research shows that heavy oils compose only 17% of the oil transported in U.S. waters, Michel said. The fact that such a high percentage of spills involve heavy oil definitely merits attention, said John Torgan, a biologist for Save the Bay, Rhode Island's largest environmental group. Ports across the country are being expanded in a competition "to get the biggest and largest ships in," he said. "When we increase the level of shipping, we may increase the risk of spills. It doesn't take an oil tanker to cause an oil spill."
The New Carissa was intentionally set afire in a failed attempt to burn the 400,000 gallons of fuel she was carrying. (Courtesy U.S. Coast Guard)
Groundings cause 62% of ocean oil spills, while 48% of inland water spills result from collisions or rammings, according to Michel. The 400,000 gallons of fuel inside the New Carissa when she first ran aground in Oregon were vulnerable to spillage because they were carried in an area below the cargo space protected only by the ship's outer shell. This is a "common" freighter fuel tank design, according to a Chamber of Shipping of America spokesperson. In response to the incident, Oregon senator Ron Wyden vowed to introduce legislation allowing the U.S. Coast Guard to refuse entry to foreign-flagged vessels, like the New Carissa, if there are safety concerns. When heavy oils are spilled, cleanup presents distinct challenges. Instead of forming continuous slicks, they tend to break up into tarry balls. Depending upon the currents, density, and turbidity of the water in which they land, these tarballs may sink, float, or "bounce around in the water like a lava lamp," said Barbara Davis, an environmental health scientist for EPA's Oil Program Center. In stormy conditions, tarballs can travel hundreds of miles, said Jacqueline
Michel, vice president of science and technology for Research Planning, Inc., a firm that provides expert oil spill support to the National Oceanic and Atmospheric Administration. She is also a member of the NRC's Committee on Marine Transportation of Heavy Oil, (but is not related to Keith Michel). Sinking heavy oils pose a significantly greater risk to bottomdwelling fish and shellfish, Jacqueline Michel said. Because spilled heavy oils weather more slowly than lighter oils, the polyaromatic hydrocarbons that they introduce may harm all fish— especially vulnerable young hatchlings—for a longer period. Even heavy oils that float—such as the 72,000 gallons of heavy oil that die New Carissa dumped into two estuaries that are home to more than $10-12 million worth of Oregon oysters, as well as a variety of clams and Dungeness crabs— behave differentiy than lighter crudes. Their tendency to break up makes diem much harder to locate, said Jacqueline Michel. They often sink just below the surface after being overwashed by waves, she said. The state-of-the-art for instruments capable of detecting submerged tarballs is "very poor," said Mervin Fingas, chief of Environment Canada's Emergencies Science Division. Furthermore, the oil companies' reduced revenues resulting from today's low oil prices make it unlikely that the needed detection technology will be developed any time soon, Jacqueline Michel said. The Coast Guard is nonetheless beginning to assess the need for this detection equipment, said Ken Bitting, program manager for the agency's Comprehensive Marine Environmental Protection Program.
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Excess nitrogen may not solve CO2 sink mystery New research suggests that nitrogen pollution has little effect on forest growth and is unlikely to account for why North American forests seem to be a sink for the global warming gas, C02. After treating North American and European forests for 1-3 years with fertilizer containing Nitrogen15, a stable isotope that is rare in nature, Knute Nadelhoffer, associate scientist at the Woods Hole Marine Biological Laboratory in Massachusetts, and his colleagues expected to find most of the labeled nitrogen in the trees. But only 5-25% was taken up as new wood growth, with the remainder going into the soil. The finding calls into question one of the leading explanations for the "disappearance" of 1.8 gigatons of carbon from the global budget, Nadelhoffer said. Scientists have estimated that 7.1 gigatons of carbon per year are emitted by human activities such as fossil fuel burning and deforestation, he explained. Of this amount, 3.3 gigatons remain in the atmosphere as C02, 2.0 gigatons are taken up by the ocean, and 1.8 gigatons mysteriously disappear over North America. Because fossil-fuel burning and agricultural fertilization have doubled the rate at which nitrogen is made available to forests, Nadelhoffer thought the surplus might augment forest growth. By growing at a faster rate, forest plants could incorporate the missing C02, thus accounting for the carbon sink. Not only is there absence of a fertilization effect, excess nitrogen actually leads to a decline in tree growth, said John Aber, professor at the University of New Hampshire's Complex Systems Research Center. His research has shown that excess nitrogen deposition leads to soil acidification, loss of soil nutrients, and decreased C02 uptake by trees. "This doesn't mean that there isn't a sink," Nadelhoffer said. He and Aber suggest that the mechanism behind the carbon sink could be reforestation, microbial activity, or a nonbiological process. —JANET PELLEY
Even after they are detected, it is harder to recover tarballs from the water because they are dispersed, Jacqueline Michel said. Five weeks after the first New Carissa spill and one week after the fuel that remained following the ship's unsuccessful burning was spilled a second time, the pounding surf had scattered tarballs along more than 150 miles of Oregon coasdine, according to the Oregon Department of Fish and Wildlife (ODFW). Workers cleaning up die beaches are simply waiting for the tarballs to wash ashore, Jacqueline Michel said. Once they splatter onto the beach, the workers scoop diem up with shovels or spear them with sticks. Though an
ODFW spokesperson called die damage "pretty minimal," more than 300 birds had been found dead. At that point, the shellfish appeared to have escaped harm, although workers were still wrestling with die challenge of disposing of die ship. "Because heavy oil is so difficult to clean up, our energies should be focused on prevention and restoration measures," Torgan said, noting that the Coast Guard considers recovering 10% of spilled oil a "successful response." "Prevention is a lot better bang for the buck," agreed Thomas Harrison, lieutenant commander for die Coast Guard's Office of Response. —KELLYN S. BETTS
Global talks to regulate genetically modified plants stall over potential trade impacts Talks in Cartagena, Columbia, aimed at crafting the first global treaty to regulate trade in genetically modified organisms (GMOs) failed in February. The breakdown marks the first time in 20 years that attempts to agree on a draft global environmental treaty under the auspices of the United Nations Environment Programme did not meet the negotiator's selfimposed deadline. Discussions stumbled when a coalition of six large agricultural exporters—the United States, Canada, Australia, Chile, Argentina, and Uruguay—pushed for the rejection of a treaty proposal based on its implications for international trade. The proposal, put forth as a compromise by the European Union (EU) at the last minute after 10 days of intense negotiations, was supported by more than 130 other countries. The biosafety protocol would set legally binding international rules to govern the transfer, handling, and use of live GMOs. To accomplish this, it would have required exporters of genetically modified plants, seeds, and other organisms to obtain advance approval from importers, as required under the Rotterdam Convention on the Prior Informed Consent (PIC) Procedure for Certain Hazardous Chemicals
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and Pesticides in International Trade (ES&T, Nov., 1998, p. 489A). Work on the proposed protocol, an outgrowth of the Convention on Biological Diversity agreed to at the 1992 Earth Summit in Rio de Janeiro, began in 1996. All countries agree that genetically engineered seeds intended for planting should be governed by an international pact. But a major disagreement in the negotiations was whether the crops of genetically engineered plants such as corn, wheat, and soybeans, which are intended for human or animal consumption, should be included in the treaty. Such crops compose more than 90% of the international trade in GMOs, according to Greenpeace International. Most developing country officials, some scientists, and environmental and consumer groups are concerned that GMO plants could confer their special characteristics on native plants through crosspollination to produce "super weeds," which would eventually obliterate native plant species. But the food and biotechnology industries and the major agricultural exporting countries argue that GMOs have a track record demonstrating that they are not a threat to biodiversity.
