U.S. Geological Survey Home Page USGS Patuxent Wildlife Research Center Science Meetings; dedicated to Chandler S. Robbins USGS Patuxent Wildlife Research Center; Science Meetings dedicated to Chandler S. Robbins Dedicated to Chan Robbins USGS Patuxent Wildlife Research Center; Science Meetings dedicated to Chandler S. Robbins Poster Abstracts from USGS Patuxent Wildlife Research Science Meetings, October, 2006
Patuxent Science Meeting 2006 Poster Abstract

Surf Scoter (Melanitta perspicillata) habitats in the mesohaline Chesapeake Bay

Kidwell DM, Perry MC

Surf scoters (Melanitta perspicillata) are one of the least studied North American waterfowl and

surveys indicate that their populations have been declining over the past several decades.

Chesapeake Bay provides important wintering area for surf scoters, where they typically feed on

bivalves. However, degraded environmental conditions have been well documented and shown

to greatly influence the composition of benthic communities. The primary objective of this study

was to determine the benthic composition of habitats utilized by surf scoters in the mesohaline

portion of Chesapeake Bay. Three areas containing large numbers of feeding scoters (>500

individuals) were chosen as the study sites, and a one kilometer by one kilometer study plot

was centered over each of the selected sites using GIS. For each site with feeding scoters

present, a corresponding one kilometer by one kilometer study plot was positioned nearby in

water of similar depth where no scoters were observed, creating site pairs. Ten sampling sites

were randomly selected in each plot of each pair and triplicate samples were taken with a

Peterson grab in August 2005. Results from site pair one showed the plot with scoters to be

high in Ischadium recurvum and Balanus improvisus while the plot without scoters was high in

Macoma balthica. This was similar to that of site pair two, where the scoter absent plot was

dominated by M. balthica, however M. mitchelli and amphipods (Family Haustoriidae) were

abundant in the scoter present sites. No difference was observed in the dominant species

(Gemma gemma and Mulinia lateralis) between plots in site pair three, thus factors other than

habitat may be driving scoter distribution at that location. These results indicate that scoters

appear to be utilizing habitats containing species associated with both hard and sand

substrates while avoiding those typically associated with mud. Results of the August sampling

will be combined with repeated sampling results from October 2005 and April 2006 in order to

gain a seasonal perspective of scoter benthic habitat.

Friday, September 22, 2006

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