The interplay between the chemical environment and the dynamics of species is of fundamental importance to ecosystems. Recruitment, predation, and biotic disturbance, for example, are commonly mediated by specific biogenic chemicals whose alteration can profoundly affect the dynamics of the community. This project will study the coupling between the presence of biogenic brominated aromatics and the dynamics of members of three trophic levels in a marine sedimentary assemblage. The project utilized the production of bromoaromatics by a worm and its contamination of the surrounding habitat as a model system for examining the following questions: 1. How does the presence of these compounds affect rates of predation and disturbance? and 2. How important are bacteria in controlling the level of sediment contamination? Based on the PI's prior research it is known that recruitment of some species is radically reduced in the presence of these bromoaromatics. However, there is a lack of information on the effects of these compounds on the major disturbance forces in the system, sediment-biting and digging predators, and on the processes that maintain the level of these toxic brominated phenols in the sediment. Using a variety of laboratory and field experiments, this research project will investigate the effects of the biogenic bromoaromatics on these processes. Given the global abundance in marine sedimentary habitats of taxa producing brominated aromatics, these compounds may be very important as structuring forces in marine sedimentary communities.
