The intertidal soft-bottom macrobenthic invertebrates

Abstract

The soft-bottom intertidal areas of the Bahía Blanca Estuary are inhabited by a diverse community of macrobenthic invertebrates. This chapter summarizes the state of our knowledge of this community, addressing its main characteristics, interrelationships and ways of life. Macrobenthic invertebrates are able to modify the physical structure and dynamics of the system, acting as architects of their own habitat. We describe the populations in terms of their role within the community and ecosystem, with particular emphasis on processes related to the removal and mobilization of sediments. Some associations between macrobenthic invertebrates and salt marsh plants are also described. Recent discoveries of newly established populations are mentioned in this chapter, together with a brief discussion of the feasible causes and consequences of their presence. Finally, we mention some of the threats to which macrofaunal communities are exposed in the estuary. Two text boxes are included in the chapter: one relating to the burrowing crab Neohelice granulata, addressing its role as an ecological ecosystem engineer; the other, relating to the hard-bottom substrates found in the estuary, focusing on the importance of this ambient in the dynamics of marine biological invasions.