THE MACROBENTHIC ECOLOGY OF THE STRAITS OF MAGELLAN AND THE BEAGLE CHANNEL

Abstract

The macrobenthic community of the Straits of Magellan and the Beagle Channel was investigated using a Reineck box corer at 22 stations during the Chilean “Cimar Fiordo 3” expedition in 1997. A total of 173 taxa represented by 2188 individuals were identified and are reported for the investigated area. Clear exponential relationships with depth were revealed by analysis of abundance, biomass, species richness, and evenness. These patterns coincide with posited theories of pelagic-benthic coupling and the source-sink hypothesis of colonisation-extinction dynamics. Polychaeta dominated macrobenthic community abundance and biomass, 67% and 38% respectively, therefore consideration of biogeographic affinities concentrated on this taxon. 13 species of polychaetes observed in the study area co-occur in Antarctica suggesting biogeographic or evolutionary affinities between these adjacent regions.