Shallow water benthic ecology: A North American perspective of sedimentary habitats

North American benthic research in sedimentary estuarine environments began with an emphasis on descriptions of organism distributions and abundance. These efforts resulted in a crude map of infaunal assemblage types. This map is not complete even today but the data allow us to ask questions about pattern. As is typical of such efforts, the majority of the techniques used to evaluate the existence of infaunal patterns are correlative and thus result in only weak inferences which do not necessarily expose the causal relationships. Such approaches dominated sedimentary benthic ecology until the 1960s and 1970s when investigators began to concentrate to a much larger extent on elucidating causal mechanisms. The original stimulus for this change has its origins in the work of Sanders and Rhoads and their collaborators who recognized the link between the activities of the infauna and the structure of the habitat. Additionally in the 1970s, several investigators with strong ties to rocky intertidal benthic ecology, where manipulative experiments have been enormously successful, began publishing their work which accelerated the move to address mechanisms through experimentation. During the 1980s and 1990s the emphasis on explicit experiments has continued. In this contribution I explore our current understanding of the processes that lead to patterns of distribution and abundance in marine sedimentary assemblages and our ability to ask testable questions concerning mechanism in this habitat.