Huang, S. Horn Point Laboratory, University of Maryland, huang@hpl.umces.edu
Newell, R. Horn Point Laboratory, University of Maryland, newell@hpl.umces.edu
Kreeger, D. A. Patrick Center for Environmental Research, Academy of Natural Sciences, kreeger@say.acnatsci.org

 
RELATIVE IMPORTANCE OF BENTHIC DIATOMS AS A FOOD SOURCE FOR RIBBED MUSSELS IN SALT MARSHES
 
We determined the quantity and composition of food resources available to suspension feeding ribbed mussels, Geukensia demissa, over tidal, lunar, and seasonal cycles in Canary Creek saltmarsh, Delaware Bay. At each tidal cycle we collected water over at hourly intervals for 6 h during the period when natural mussel populations were submerged. A high degree of variation in total seston and composition was found within each tidal cycle. Although food quantity did not vary seasonally there were seasonal variations in quality and composition. Phytoplankton was the dominant component of POM in the spring whereas bacteria and heterotrophic nanoflagellates were abundant in the summer. Benthic diatoms were observed at all seasons in the water column and contributed significantly to the mussel's diet. Unexpectedly the abundance of benthic diatoms was not related to the tidal level. Phytoplankton concentrations were highest during high slack water and lowest during the ebb tide in most tidal cycles, indicating that Canary Creek marsh is a net sink for phytoplankton produced in the adjoining Delaware Bay. We calculated that the relative carbon contribution of phytoplankton > benthic diatoms > microheterotrophs > detrital cellulose in the annual diet of ribbed mussels.
 
Day: Friday, Feb. 5
Time: 11:15 - 11:30am
Location: Eldorado Hotel
 
Code: SS46FR1115E