Patterns of Succession in Benthic Infaunal Communities Following Dredging and Dredged Material Disposal in Monterey Bay

This report deals with the patterns of benthic succession in soft-bottom marine communities. The primary study objective was to elucidate and evaluate the mechanisms that control these patterns. Benthic succession is the pattern of community recovery following a perturbation. Controlled perturbations of bottom communities were effected by the dredging of locations in Moss Landing Harbor and by the disposal of dredged material in Monterey Bay, Calif. The general pattern of succession was highly dependent upon the nature of the physical environment and the structure of surrounding communities. The open coast communities of Monterey Bay are numerically dominated by small crustaceans and polychaetes. Succession was divided into an early and a late phase. The early phase was characterized by the immigration of peracarid crustaceans and the settlement of the larvae of relatively opportunistic species of polychaetes. The latter have relatively short generation times, small size, low fecundity and high larval availability (frequency and abundance of larve in the water). These opportunistic are uncommon in the natural, undisturbed bottom community. The later phase of succession was characterized by the gradual reestablishment of the less mobile crustaceans and less opportunistic polychaetes that inhabited the areas prior to the experimental distrubances. It was concluded that the management of benthic marine resources and dredging operations should involve an analysis of the natural distrubance regime at a potential dredging or disposal site and its relation to the associated bottom communities. Report on Dredged Material Research Program.