Biological invasions may result in significant changes to recipient communities. Changes to native populations are among the most important impacts. In many instances, non-native species can adversely affect native populations through predation or competition for limiting resources. Likewise, native populations repel intruders via the same interactions, thereby preventing the establishment or spread of introduced species. The introduction of non-native parasites and diseases into a recipient ecosystem or escape of parasites and diseases in a host's native range may have important ramifications for a population's dynamics as well. In addition to biological pressures, physical aspects of the environment such as salinity and temperature regimes, affect the invasibility of habitats.

Elucidating the ecological and biological underpinnings of the invasion process is vital to understanding how best to prevent new introductions and how to effectively manage existing invasions. The Marine Invasions Research Laboratory at SERC is actively engaged in a series of field experiments and surveys that focus on the effects of invasion on demography and population dynamics of target species. Several our studies are directed at comparing the biology of native and non-native populations of the same species across broad geographic scales. We are currently investigating Atlantic (native) and Pacific (introduced) populations of the mud crab, Rhithropanopeus harrisii, the amethyst gem clam Gemma gemma, and the rough periwinkle, Littorina saxatilis to quantify differences in size-specific fecundity, reproductive schedule, and other demographic characters. The European Green Crab, Carcinus maenas is also a major focus of extensive field and laboratory investigations at SERC.