The structure, dynamics, and function of coastal marine communities result from the interaction of many different factors, which are changing in space and time. Coastal ecosystems are increasingly being shaped by human activities, which strongly affect hydrology, chemical inputs, fishery stocks, species introductions, as well as quantity and quality of available habitats. Such changes are also occurring, and interacting with, changes in global climate and a wide range of associated forcing functions.

Our research examines several facets of change in the structure, function, and dynamics of marine communities. Our work can be subdivided into two general areas: One focuses on biological invasions; the other examines predator-prey interactions in soft-sediment marine communities.

Biological Invasions: We are interested broadly in the interplay between invasions and the recipient communities. Our research in this area explores the bi-directional interaction between non-native species and recipient communities:

• Effects of non-native species on recipient communities: Through descriptive and experimental approaches, we are exploring the effects of such species insertions (invasions) on community structure, including species composition and abundance of resident assemblages. While our work focuses on particular species, we are also interested in whether predictable patterns exist across taxa for type and magnitude of invasion impacts.
• Effects of recipient communities on non-native species: Our research is simultaneously exploring how various attributes of recipient communities may influence the colonization, spread, and abundance of non-native species. A great deal of literature suggests the importance of such factors as disturbance and species diversity in the invasibility of communities. We are pursuing both correlative and experimental analyses across bays in North America to test for such relationships.

Most of our work in this area focuses on hard substrate fouling communities in bays and estuaries. Fouling organisms comprise more than half of the known non-native species that are known to be established in North America. Moreover, these communities are well studied and conducive to experimental manipulation.

Predator-Prey Interactions: This facet of our research examines effects of predators on prey populations and structure of soft-sediment communities. A great deal of our work in this area focuses on nearshore epibenthic communities in the Chesapeake Bay. We are particularly interested in temporal changes in predator abundance and predation pressure and its effects on (a) prey distribution, demography, and behavior and (b) community structure and foodweb dynamics.