Biology Seminar: Dr. Brad Peterson

There is a rich history of plant-animal interactions within seagrass meadows. As foundation species, seagrasses host a diverse array of associated fauna. Although the direct positive impact of seagrass habitat structure on faunal diversity and abundance is widely acknowledged, the role of animals on seagrass productivity and resilience range dramatically from positive to negative. Often these plant-animal interactions even involving the same species change along gradients of environmental stress. My research has focused on two overarching questions:  How do organisms mediate resource flows within a community? and How do positive interactions regulate community structure, function and stability? In this seminar, several field and laboratory experiments will be presented to highlight positive plant-animal interactions in both temperate and subtropical seagrass assemblages.  We will examine the role of bivalves in fertilizing seagrass, reducing sediment sulfide stress, increasing reproductive output and ameliorating light stress.  All of these studies suggest that seagrass meadows exist as a mosaic of nutrient and productivity “hotspots” when suspension feeding organisms are present.  These positive interactions are critical components of many ecological processes and therefore have important consequences in the development, structure, stability and restoration of seagrass communities.