Monday, November 5, 2007
A different project:
While the focus of this blog will be concentrating the various aspects of my current graduate research, I wanted to make a small diversion to some research I did a few years ago with hard clams and eelgrass. I did benthic surveys for eelgrass abundance and hard clam densities in Shinnecock and Quantuck Bays on Long Island. While I only found 14% of the sites to have eelgrass, 67% of eelgrass sites had hard clams present, and only 33% of all other sites had hard clams present. Further, the densities of hard clams in eelgrass sites were double the densities outside of eelgrass. The reasons for this have been greatly explored in the literature, most often that below ground biomass of eelgrass offers a refuge from predation by crabs and whelks. However, little work ha been done to determine the impacts hard clams have on eelgrass. I was able to show that the addition of one hard clam to a quadrat of eelgrass (the equivalent of 16 hard clams per square meter) increased the eelgrass productivity (growth) about as much as a commercial fertilizer via nutrient additions. How? Hard clams filter the water column of phytoplankton and small zooplankton, and then repackage those as nutrients released to the sediments, which the eelgrass then uses for growth. It seems that there is an interactive relationship between the hard clams and eelgrass. I just submitted this work for publication in the Marine Ecology Progress Series, and if it gets accepted, it will be my first publication.