Biodiversity and functioning of polychaetes in benthic sediments

Polychaetes are well represented in most marine and estuarine environments, both in terms of number of individuals and species, and they typically con tribute a significant percentage of the total macrofaunal diversity. They e xhibit considerable variations in recruitment in both time and space, which is then often reflected in adult distributions. Whilst families and genera of polychaetes have wide distributions, normally species have discrete dis tributions. Polychaetes are often classified according to their diverse fee ding guilds. They play a major role in the functioning of benthic communiti es, in terms of recycling and reworking of benthic sediments, bioturbating sediments and in the burial of organic matter. Some species form dense tubi culous colonies which can radically change recruitment patterns of other in faunal organisms. Polychaetes, by their burrowing and feeding activity, may considerably enhance various sedimentary processes. However, much remains to be learnt as to how benthic communities function, and how they may chang e in function as they are increasingly being impacted especially in coastal waters adjacent to centres of population.