Decadal Changes in Macrobenthos Along a Latitudinal Gradient on the West Antarctic Peninsula Continental Shelf

Abstract

As a result of rapid regional warming of the Antarctic Peninsula there has been an increase in melt-water (Clarke et al., 2007; Scambos et al., 2003), the loss of seven ice shelves (Vaughn and Doake, 1996), and a decrease in sea-ice concentration and duration along the Western Antarctic Peninsula continental shelf (WAPcs) and Bellinghausen Sea (Jacobs and Comiso, 1997; Smith and Stammerjohn, 2001). Our quantitative research of macrobenthic abundance (N/m2), biomass (g/m2), and mean body size (g/N) on the WAPcs reveal significant latitudinal gradients and decadal changes since 1985(Mühlenhardt-Siegel, 1988). We hypothesize that these decadal changes are associated with decadal rates of decreased and increased overlying primary productivity in the northern and southern subregions of the WAPcs, respectively, which is in turn a function of overall decreased sea-ice cover (Montes-Hugo et al., 2009).