INJURY TO BIRDS AND DIAMONDBACK TERRAPINS RESULTINGFROM THE CHALK POINT OIL SPILL, MARYLAND

摘要

A pipeline spill of 126,000 gallons of a mixture ofNo.6 and No. 2 fuel oils into the Patuxent River on 7 April 2000affected over-wintering waterfowl, resident birds, anddiamondback terrapins, as well as intertidal habitats, fish andshellfish, benthic habitats, and muskrats. The final estimate ofbird impacts was the sum of the numbers of birds collected dead,dying in rehabilitation, and estimated to have died after releaseand in the field. The result was an estimated 495 total birdskilled, with 67 known dead. The total terrapin mortality wasestimated by projecting: a) the number of terrapin-years lost frommortality of adults and juveniles killed directly (estimated to be122 animals) by the spill, b) the estimated number of young thatwould have been born and survived to adults from those directlykilled, and c) increased hatchling mortality. The final estimate ofdirect terrapin mortality was 616 lost discounted terrapin-years(DTYs), while lost production from the next generationcontributed 3,793 lost DTYs. The loss due to increased hatchlingmortality was 836 DTYs. The total injury to Patuxent Riverdiamondback terrapins was estimated to be a loss of 5,245 DTYs.