| 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 |