Wintering Sea Duck Distribution Along the Atlantic Coast of the United States

Abstract

Although monitoring data for sea ducks (Tribe Mergini) are limited, current evidence suggests that four of the most common species wintering along the eastern coast of the United States—long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca, surf scoter Melanitta perspicillata, and black scoter Melanitta americana—may be declining, while the status of American common eider Somateria mollissima dresseri is uncertain. The apparent negative trends, combined with the fact that sea duck life histories are among the most poorly documented of North American waterfowl, have led to concerns for these species and questions about the impacts of human activities, such as hunting, as well as catastrophic events and environmental change. During winter, thousands of sea ducks are found along the U.S. Atlantic coast, where they may be affected by proposed wind-power development, changes to marine traffic, aquaculture practices, sand mining, and other coastal development. Possible impacts are difficult to quantify because traditional winter waterfowl surveys do not cover many of the marine habitats used by sea ducks. Thus, the U.S. Fish and Wildlife Service conducted an experimental survey of sea ducks from 2008 to 2011 to characterize their winter distributions along the U.S. Atlantic coast. Each year, data were collected on 11 species of sea ducks on >200 transects, stretching from Maine to Florida. In this paper, we describe distribution of common eider, long-tailed duck, white-winged scoter, surf scoter, and black scoter. Densities of the two species with the most northerly distribution, white-winged scoter and common eider, were highest near Cape Cod and Nantucket. Long-tailed duck was most abundant around Cape Cod, Nantucket Shoals, and in Chesapeake Bay. Surf scoter also concentrated within Chesapeake Bay; however, they were additionally found in high densities in Delaware Bay, and along the Maryland–Delaware outer coast. Black scoter, the most widely distributed species, occurred at high densities along the South Carolina coast and the mouth of Chesapeake Bay. Spatial patterns of high-density transects were consistent among years for all species except black scoter, which exhibited the most interannual variation in distribution. The distance from land, depth, and bottom slope where flocks were observed varied among species and regions, with a median distance of 3.8 km from land along the coastal transects and 75% of flocks observed over depths of <16 m. Common eider and long-tailed duck were observed closer to shore and over steeper ocean bottoms than were the three scoter species. Our results represent the first large-scale quantitative description of winter sea duck distribution along the U.S. Atlantic coast, and should guide the development of sea duck monitoring programs and aid the assessment of potential impacts of ongoing and proposed offshore development.

Body composition dynamics of common eider during winter: An application of the deuterium dilution method

“…The nearshore waters of southern New England are generally shallow, with increased depth gently sloping seaward (Theroux andWigley 1998, Eakins et al 2009) that provides extensive habitat for eider and other sea ducks because they prefer to forage in water depths up to 20 m (Goudie et al 2000). As such, southern New England supports the greatest relative densities of wintering sea ducks on the western Atlantic Coast (Silverman et al 2013).…”

“…North America's largest species of sea duck, the common eider (Somateria mollissima; hereafter, eider), is widespread and abundant during winter in northeastern North America (Goudie et al 2000, Silverman et al 2013, and thus is an ideal species for investigating changes in body composition throughout winter. Thousands of American common eider (S. m. dresseri) winter nearshore in southern New England (Klimstra andPadding 2012, Silverman et al 2013) where individuals are exposed to harvest by hunters (Raftovich et al 2011), habitat loss and degradation (Goudie et al 2000, Thrush andDayton 2002), inclement weather, and novel diseases (Pello and Olsen 2013) including Wellfleet Bay Virus, a newly described, emerging regional disease (Allison et al 2015).…”

Spatial ecology of long‐tailed ducks and white‐winged scoters wintering on Nantucket Shoals

“…A small number of critical feeding areas on the U.S. eastern seaboard sustain a large proportion of its wintering sea ducks (family: Anatidae; tribe: Mergini; White et al 2009, Nisbet et al 2013, Silverman et al 2013, Veit et al 2016. However, there is little information on how oceanic prey resources influence wintering sea duck distributions on the Atlantic United States, outside of bays and harbors.…”

Validating the deuterium dilution method to measure body composition of common eider

“…m . dresseri ) winter nearshore in southern New England, USA (Klimstra and Padding , Silverman et al ).…”

“…Our goal was to validate the deuterium dilution method for estimating body composition of one species of sea duck, the common eider. Common eider (hereafter, eider) is the largest species of North American sea duck and is widespread and abundant during winter in northeastern North America (Goudie et al 2000, Silverman et al 2013). Thousands of American common eiders (S. m. dresseri) winter nearshore in southern New England, USA (Klimstra andPadding 2012, Silverman et al 2013).…”