BioBriefs Of Oyster Shells and Oil Spills Beth Baker In 1887, when amateur naturalist Josiah Willcox strolled along Florida’s Gulf coast, he could not have imag­ ined how an ordinary oyster shell he collected would be used for research more than a century later. Willcox, as would any good naturalist, recorded the place and time of his find. Thanks to that collection data, the shell today plays an important role in a unique study of the effects of the 2010 BP oil spill on the food web in the Gulf of Mexico. Soon after the spill, Paul Callo­ mon, who manages the malacology (mollusk) collection of the Academy of Natural Sciences in Philadelphia, received a call from Peter Roopnarine, curator of geology at the California Academy of Sciences. Roopnarine wanted to borrow old oyster shells as a baseline for a study of crude oil’s impact on organisms in the Gulf. The academy was certainly the place to call. Its malacology collec­ tion, the nation’s oldest, contains some 10 million specimens, weighing 55 tons. Moreover, the entire collection’s data are digitized, making it easy for Callomon to put his hands on 105 specimens from the Gulf of Mexico, collected between 1887 and 1960. Having access to these shells was essential to the study, said Roopnarine. Even before the spill, the Gulf was hardly a pristine environment. Fifty thousand oil wells have been drilled there since the 1930s. In addition, natural oil seeps may contribute to contamination of the organisms. The challenge is determining which con­ taminants found in mollusks are from the 2010 spill. To do so, Roopnarine and colleagues are analyzing specimens from three time periods: 1887–2000, May 2010 (just after the spill), and August 2010. In addition to the popular Eastern oyster (Crassostrea virginica), they are examining a clam (Tellina lineata), a marsh mussel (Geukensia demissa), and a marsh periwinkle (Littoraria irrorata). Older specimens were also lent by the California Academy and the Santa Bar­ bara Museum of Natural History. “We’re trying to determine if any components from the crude oil are incorporated into the shells and tis­ sues of a number of organisms,” Roop­ narine explained, “and from that we plan to make modeling predictions about how these materials might be distributed throughout the food web.” The BP spill dwarfed all others, save the deliberate dumping of oil by the Iraqi government during the first Persian Gulf War. When BP’s Deepwater Horizon drilling rig exploded, 11 people were killed and more than 600,000 tons of oil gushed into the Gulf of Mexico from April 20 for the next 104 days. By comparison, the 1989 Exxon Valdez accident caused a spill of 37,000 tons of oil. Roopnarine had been working on food­web modeling and the effects of large­scale disturbances in San Fran­ cisco Bay. When he learned of the BP spill, he knew it presented researchers with a rare opportunity. “This was huge,” he said. “I contacted a colleague at Louisiana State [Laurie Anderson, now at the South Dakota School of Mines and Technology] and within 10 days, she was out on the coast col­ lecting material.” Preliminary data presented at the American Geophysical Union 2011 meeting indicate significantly higher concentrations of vanadium, lead, and chromium in the shells of the postspill oyster specimens, whereas the soft tis­ sue had higher levels of vanadium, lead, and cobalt. The researchers are also looking for hydrocarbons in the soft tissue. Although heavy metals are not known to harm oysters directly, they may pose a risk to other animals throughout the food web, including humans. Because of the politically charged nature of the Gulf spill and the economic repercussions if the oys­ ter fishery were harmed, the research­ ers are increasing their sample size and repeating the study before publishing results. Roopnarine knows of only one similar study, published in Aquatic Living Resources in 2004, of a much smaller oil spill in France. Further complicating the analyses are the mitigation efforts following the spill. To prevent the oil from com­ ing ashore, chemical dispersants of unknown quantity and composition were injected into the water column. In addition, a massive amount of fresh water was flushed into the Gulf, poten­ tially causing havoc to the ecosystem. “We’d love to look at the disper­ sants,” said Roopnarine. “To the best of our knowledge, the dispersant used was an organic material, but we don’t have access to the complete or exact composition. It’s proprietary.” The study, added Callomon, is one more example of the importance of not only conserving biological collec­ tions but having them readily available through digitization. “Field collection of even common things, with accurate data of when and where they were col­ lected, is even more important than 100 years ago, when things weren’t changing as fast as they are now,” he said. “We collect them with the knowl­ edge that one day, they’ll be of vital importance. Keeping a record is a very important scientific activity. Happily, it’s one that anyone can do.” Beth Baker (bbaker@aibs.org) is a freelance writer and features editor of BioScience. doi:10.1525/bio.2012.62.2.19 212 BioScience • February 2012 / Vol. 62 No. 2 www.biosciencemag.org

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