MEPS 264:221-232 (2003)  -  doi:10.3354/meps264221

Scaling restoration to achieve quantitative enhancement of loon, seaduck, and other seabird populations

Molly B. Sperduto1,*, Sean P. Powers2, Michael Donlan3

1United States Fish and Wildlife Service, 70 Commercial Street, Suite 300, Concord, New Hampshire 03301, USA
2Department of Marine Sciences, University of South Alabama and Dauphin Island Sea Lab, 101 Bienville Blvd., Dauphin Island, Alabama 36528, USA
3Industrial Economics, 2067 Massachusetts Avenue, Cambridge, Massachusetts 02140, USA

ABSTRACT: The 1996 ŒNorth Cape¹ oil spill along the Rhode Island coast led to the deaths of at least 2292 birds, resulting in an estimated 6275 bird-years lost (adjusted by expected longevity and productivity). We synthesize information on bird population dynamics to develop an appropriate restoration strategy. Marine birds (seaducks, loons, grebes) with natural recovery periods estimated to exceed 1 yr accounted for 87% of the total bird-years lost. Marine birds (gulls, cormorants, alcids, gannets) with recovery estimated to be less than a year accounted for 10% of injuries. Common loons Gavia immer and common eiders Somateria mollissima were selected as targets for restoration because of regional concern over their population status and the magnitude of lost bird-years. Three restoration options were evaluated for loons: nest site protection; nest site enhancement; and public education/outreach. Nest site enhancement opportunities were limited and benefits from public education/outreach efforts were uncertain. Nest site protection was preferred for both loons and eiders because nest site availability and/or quality currently limit(s) productivity. This option assumes that preventing future productivity loss compensates for productivity loss that resulted from the ŒNorth Cape¹ oil spill. This assumption is supported by regional productivity estimates for the 2 target species, is consistent with scientific literature, and represents the consensus of expert opinions. Based on a series of scaling calculations, protection of 25 nest sites for a 100 yr period is expected to balance the loss of 2920 loon-years. Protection of 315 eider nest sites over a 100 yr period would replace 2605 bird-years lost (remaining marine bird injury). Calculations adjust future production credit through economic discounting of 3% yr-1. Our analysis provides a means of quantifying the level of breeding habitat protection required to restore injured populations of marine birds.


KEY WORDS: Restoration · Habitat protection · Marine birds · Oil spill · Seabird · Habitat equivalency analysis


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