U.S. GLOBEC NEWS, Vol. 1, No. 2, Fall 1991


Contributed by Eileen Hofmann and Mark Huntley

From 9 to 11 May 1991 a workshop entitled "GLOBEC: Marine Animal Populations and Climate Change in the Southern Ocean" was held at Scripps Institution of Oceanography. This workshop was one in a series convened as part of the GLOBal Ocean ECosystem Dynamics (GLOBEC) initiative, funded by NSF and NOAA, which has as its general objective the understanding of processes relating to and controlling variability in marine populations.

The Southem Ocean Workshop brought together approximately 40 scientists from 10 countries to develop a science plan that can be used to outline a GLOBEC-related study in Antarctica. The first day of the workshop consisted of a series of plenary talks that provided overviews on zooplankton, fish, and benthicpopulations of the Antarctic. Also presented were overviews of the Fine Resolution Antarctic Model (FRAM), physical oceanography, regional circulation effects on biological distributions, ice cover trends, and the paleocirculation/climate of the Antarctic. Following the plenary presentations, workshop participants separated into eight working groups.

Discussions of the working groups centered around issues relating to physics and climate, zooplankton and krill, benthos, top predators, modeling, physiological rates, new technology, and population dynamics. The results of the working group deliberations and recommendations are given in the report from the workshop. Also included in the report are several background papers that resulted from the plenary session talks. The workshop report will be available in early 1992 and will be distributed as a GLOBEC publication through JOI.

From the plenary presentations and working group discussions, it was apparent that the annual retreat and formation of pack ice may be the major determinant of spatial and temporal changes in the structure and function of Antarctic marine communities. Thus, it was recognized that there is a critical need for austral winter observations of populations in the Antarctic and that any study must be of sufficient duration to include several ice cover cycles. In particular, observations are needed for Antarctic krill (Euphausia superba) and the salp (Salpa thompsoni), which were identified as the key target species. Suggested target fish species included a commercially harvested species (e.g., Champsocephalus gunnari), a nonharvested holopelagic species (e.g., Pieurogramma antarctica) and nonharvested near-shore species (e.g., Notothenia neglecta). Other top predators, such as a variety of penguin species, the crab-eater seal, and the Antractic fur seal were recognized to be very important and recommendations were made to include these in a GLOBEC Southern Ocean program.

The consensus of the workshop participants was that a GLOBEC-sponsored initiative be planned for the eastern Bellingshausen Sea adjacent to the Antarctic Peninsula coastal region. This area was chosen because available information indicates that it contains an identifiable gyre which could provide a mechanism to isolate populations with planktonic stages. This region contains relatively large populations of the key species recommended for study, including krill, a variety of benthic species and important species of fish, seabirds, and seals. Also, sea ice is a consistent feature in the eastern Bellingshausen Sea, which will allow the study of sea ice dynamics in relation to population dynamics of the key species. Finally, this region is relatively easy to access by research vessel, and is near the highest concentration of shore-based marine laboratories on the Antarctic continent, which will provide for high-quality logistic and scientific support Secondary sites recommended for study include the southeastern Weddell Sea, the northern part of the Atlantic sector of the Southern Ocean, and the Ross Sea area.

Following the recommendations of the workshop, the next step will be the development of an implementation plan for a GLOBEC-sponsored Southern Ocean program. 1996-97 was identified as the potential time frame for the implementation of this program. It is expected that a Southern Ocean GLOBEC program will involve participation by many nations.