| In 2003, the National Research Council published Oil in the Sea III, a widely respected report that highlights priority areas for oil spill research. Cited as a "high priority" was the study of "chronic biological effects resulting from the persistence of medium and high molecular weight aromatic hydrocarbons and heterocyclic compounds and their degradation products in sediments..." In September 1969, the barge Florida ran aground in Buzzards Bay, Massachusetts and spilled 700,000 L of No. 2 fuel oil, which entered Wild Harbor. Recent work found that a substantial residue of the oil was still present 8 to 20 cm below the salt marsh surface. To examine the unknown lingering effects of petroleum exposure, I examined responses in organisms known to encounter buried oil, salt marsh fiddler crabs, Uca pugnax, salt marsh cord grass, Spartina alterniflora, and ribbed mussels, Geukensia demissa.;Uca pugnax, which burrow into the sediments at depths of 5 to 25 cm, are chronically exposed to the spilled oil. Behavioral studies conducted with U. pugnax from Wild Harbor and a control site, Great Sippewissett marsh, found that crabs exposed to the oil avoided burrowing into oiled layers, suffered delayed escape responses, lowered feeding rates, and lower population densities.;Spartina alterniflora grows in the oiled sediments and is chronically exposed to the spilled oil. Vegetation sampling in Wild Harbor and a control site, Great Sippewissett marsh, showed that above- and below-ground biomass decreased in oiled areas. Further, the decreased vegetation biomass has led to unconsolidated sediments, increased topographical variation and, ultimately, loss of salt marsh habitat.;The ribbed mussel, Geukensia demissa, which live in sediments previously determined to be eroding at the creek bank, are exposed to the spilled oil. Studies of G. demissa from Wild Harbor and Great Sippewissett march, found that mussles exposed to the oil following exposure, exhibit slower growth rates, shorter mean shell lengths, lower condition indices, and decreased filtration rate.;These results add new knowledge about long-term consequences of spilled oil, a component that should be included in assessments of oil-impacted areas and development of management plans designed to restore, rehabilitate, or replace impacted areas. |
