GLOBEC looks south

The Global Ocean Ecosystem Dynamics (GLOBEC) is an international scientific program whose primary objective is to understand how marine populations vary in response to changes in their environment. The program has identified the unique characteristics of the Antarctic marine food web in the Southern Ocean region as ideal for addressing GLOBEC’s main objectives.

Southern Ocean GLOBEC (SO-GLOBEC) has been designed to study the year round life cycle of Antarctic pelagic animals, particularly Antarctic krill. It involves Germany, the United States, Australia, Japan, Korea, South Africa, the United Kingdom and the International Whaling Commission (IWC).

A single key species, Antarctic krill, Euphausia superba, provides the mechanism for linking environmental variability and primary production processes with predator species, such as penguins and seals. An environmental linkage is also made by the fact that many components of this food web depend on sea ice during some or all of their life history.

These unique characteristics make the Antarctic marine ecosystem potentially vulnerable to changes in environmental conditions, or to resource exploitation. However, predictions of how this system will respond to environmental variability and climate change first require understanding of the cycles of natural population variability, especially in those that occur in response to physical variability.

An intensive US SO-GLOBEC research program in 2001–02 has focused on Marguerite Bay in the Western Antarctic Peninsula region. Two research vessels, Nathaniel B. Palmer and Lawrence M. Gould, have made consecutive autumn–winter cruises. The Australian contribution of a marine research voyage, curtailed in 2000–01 for logistic reasons, is now scheduled for January–February 2003.

The voyage involves a detailed examination of the structure and movement of krill swarms near Mawson station, where an Adélie penguin colony has been intensively studied for the past 12 years as part of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Ecosystem Monitoring Program (CEMP). The study, in a small survey area important to krill-feeding predators, aims mainly to determine the fine scale abundances and temporal variation in the horizontal and vertical distribution of krill and other key pelagic species, in relation to water column structure and water mass movements.

Stephen Nicol*, Program Leader, Antarctic Marine Living Resources

* The author is a member of GLOBEC’s Southern Ocean and Scientific Steering Committees.