How do animals interact with their environment and each other?

 

My research focuses on understanding the relative influence of negative trophic interactions such as grazing and predation versus non-trophic positive interactions (mutualisms and facilitations) in structuring seagrass communities.

Previous research has shown that the removal of the great sharks from the oceans has led to the rise of smaller elasmobranchs including rays and skates. This trophic cascade has been the topic of much debate, and the cownose ray in particular has been implicated for having dramatic effects on bivalve populations. But what about their effect on the habitat in which scallops live-- seagrass beds?

 (Heithaus et al. 2008)

(Heithaus et al. 2008)

Specifically, my research seeks to understand the relative impact of top-down versus bottom-up influences on seagrass bed expansion and growth. To do so, I am testing how excluding large predators in concert with nutrient addition affects the growth of seagrass beds in North Carolina. 

 

Check out the video below to see how we installed these exclusion cages!