Benthic communities of the Weddell Sea : Past, present and future

Abstract

The present thesis tackles different aspects of the past, present and future of high Antarctic benthic communities of the Weddell Sea. It first compares methodological approaches to sample benthos, showing the complementarity of two quantitative techniques. Then reviews knowledge on bentho-pelagic coupling on Antarctic shelves, showing that bentho-pelagic coupling differs considerably based on local characteristics. This methodological and conceptual knowledge is uses to study the benthic communities in the hard to access Filchner Region (southern Weddell Sea), describing two "novel" communities, and shows the influence of environmental drivers over benthic distribution. The final topic is the temporal dynamics of benthos. For this, a long-term study which considers a unique 26-year time series of benthic data from the southeastern Weddell Sea is used. Here, benthic communities appear severely affected by a decrease of productivity, and increase of scouring potential, especially after the year 2000.