The Antarctic-Magellan connection: macrobenthos ecology on the shelf and upper slope, a progress report
Résumé
Ecological work carried out on the Antarctic and Magellan shelves since the first IBMANT conference heldat the UMAG, Punta Arenas in 1997 is summarized to identify areas where progress has been made and others, where impor-tant gaps have remained in understanding past and present interaction between the Antarctic and the southern tip of SouthAmerica. This information is complementary to a review on shallow-water work along the Scotia Arc (Barnes, 2005) andrecent work done in the deep sea (Brandt and Hilbig, 2004). While principally referring to shipboard work in deeper water,above all during the recent international EASIZ and LAMPOS campaigns, relevant work from shore stations is also includ-ed. Six years after the first IBMANT symposium, significant progress has been made along the latitudinal gradient from theMagellan region to the high Antarctic in the fields of biodiversity, biogeography and community structure, life strategiesand adaptations, the role of disturbance and its significance for biodiversity, and trophic coupling of the benthic realm withthe water column and sea ice. A better understanding has developed of the role of evolutionary and ecological factors inshaping past and present-day environmental conditions, species composition and distribution, and ecosystem functioning.Furthermore, the science community engaged in unravelling Antarctic-Magellan interactions has advanced in methodolog-ical aspects such as new analytical approaches for comparing biodiversity derived from visual methods, growth and agedetermination, trophic modelling using stable isotope ratios, and molecular approaches for taxonomic and phylogenetic pur-poses. At the same time, much effort has been invested to complement the species inventory of the two adjacent regions.However, much work remains to be done to fill the numerous gaps. Some perspectives are outlined in this review, and sug-gestions are made where particular emphasis should be placed in future work, much of which will be developed in the frameof SCAR’s EBA (Evolution and Biodiversity in the Antarctic) programme.