The relative importance of dispersal and interspecific interactions to food webs.

I focus my research on a field model ecosystem: freshwater rock pools. The Isles of Shoals Archipelago is a chain of nine granitic islands off the coast of Portsmouth, NH.

All of these islands have rock pools, and the largest island, Appledore, is also the home of Shoals Marine Lab, which is co-operated by Cornell University and the University of New Hampshore. Appledore has approximately 1000 pools and is the main site for my field work.

These rock pools house a fairly simple food web, primarily consisting of green algae, cladoceran grazers (Daphnia and Moina), and an insect predator (Trichocorixa, a water boatman).

An important part of my research is understanding the food web interactions that occur within a rock pool. In particular, I am interested in understanding the role that Trichocorixa plays in the food web, since it is an omnivorous scavenger, but one that is very capable at capturing and consuming live zooplankton. Trichcocorixa has five juvenile instars and an adult stages (growth from 40 µg to over 1 mg), and so I am interested in the role that their ontogeny plays in their trophic interactions.

I am also measuring among-pool dispersal for all of the organisms in the rock pools. Trichcocorixa adults can fly among pools, and all of the organisms are passively transferred between pools by water outflows, wind, and gulls.