Restoration of oiled mussel beds in Prince William Sound, Alaska

• Published in: Marine environmental research 2004-06, Vol.57 (5), p.359-376
• Main Authors: Carls, Mark G, Harris, Patricia M, Rice, S.D
• Format: Article
• Language: English
• Subjects: Accidents; Alaska; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Bivalvia; Conservation, protection and management of environment and wildlife; Environmental degradation: ecosystems survey and restoration; Environmental Monitoring; Environmental Pollution - prevention & control; Exxon Valdez; Fuel Oils - poisoning; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Hydrocarbons - metabolism; Hydrocarbons - pharmacokinetics; Hydrocarbons - poisoning; Marine; Monitoring; Mussels; Mytilus trossulus; Oil spills; Petroleum hydrocarbons; Population Dynamics; Prince William Sound; Restoration; Ships; Tissue Distribution
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2003.11.002

Natural loss of hydrocarbons was often low from mussel ( Mytilus trossulus) beds (which were typically not cleaned after the Exxon Valdez oil spill), thus this habitat remained a long-term source of oil. Consequently, experimental restoration of nine contaminated beds was attempted in 1994; mussels were removed, contaminated surface sediment was replaced (33 metric tons), and original mussels were returned. Hydrocarbon concentrations and mussel populations were monitored for 5 years thereafter. Post-restoration mussel population fluctuations were indistinguishable from regional changes. Increased short-term oil loss was apparent, but long-term (5 year) improvement was equivocal and difficult to distinguish from natural losses. By 1999, oil concentrations in mussels were typically at baseline levels in restored and oiled reference beds; concentrations in replaced sediment were elevated in one third of restored beds, indicating recontamination from underlying or surrounding sediment. Our results suggest mussel relocation is feasible but suggest oil might more effectively be removed from sediment mechanically or chemically than manually.