Southern Ocean Continuous Plankton Recorder Survey (SCAR)
|
Antarctic plankton are expected to be particularly sensitive and vulnerable to climate change. Global warming will affect sea ice patterns and plankton distributions. Increased UV levels, ocean acidification, invasive plankton species, pollution and harvesting impacts are also potential major threats. At this stage we do not know the synergistic effects of any of the threats acting in combination. The SCAR SO-CPR Survey was established in 1991 by the Australian Antarctic Division to map the spatial-temporal patterns of zooplankton and then to use the sensitivity of plankton to environmental change as early warning indicators of the health of the Southern Ocean. It also serves as reference for other monitoring programs such as CCAMLR's Ecosystem Monitoring Program C- EMP and the developing Southern Ocean Observing System. Seven countries have participated in the Survey to date, Australia, Japan, Germany, New Zealand, United Kingdom (by SAHFOS and the British Antarctic Survey), USA and Russia, providing a near circum-Antarctic Survey. A South American consortium of Brazil, Uruguay, Argentina, Chile, Peru, Ecuador and Venezuela has been established in order to contribute to the Census of Antarctic Marine Life. The consortium will also join the SO-CPR Survey in the Antarctic 2008/09 season with regular CPR tows across Drake Passage. France will also join in 2008/09 with tows between Hobart and the French station Dumont d'Urville and these tows will also contribute to the new Australian AusCPR Survey. The SO-CPR Survey is supported by the SCAR Expert Group on Continuous Plankton Research, which helps promote and develop the Survey. The Southern Ocean CPRs are towed from research and supply vessels that also collect at the same time underway data such as sea surface temperature, salinity, fluorometry, light and other oceanographic-meteorological parameters. The silks are processed in laboratory by trained plankton taxonomists in Australia, Japan and UK (SAHFOS). Other centres are being developed in New Zealand and another centre is being established in South America. All plankton in five nautical mile equivalent sections are identified to the lowest possible taxa, usually species and counted. Antarctic krill and other euphausiids are identified to developmental stage. Plankton counts are combined with averaged environmental data for each 5nmile. Tows have been made around most of Antarctic (~70%) with new additional tows made in the Bellingshausen Sea and Drakes Passage. Much of the Amundsen and Bellingshausen seas, and eastern Weddell Sea have not been surveyed. Approximately 40-50 tows are made each year, although more than 80 tows were completed in 2007-08 International Polar Year for CAML. 135,000nmiles of data have been collected since 1991, producing more than 27,000 samples for 200+ taxa coupled with environmental data. Most data comes from the October to April period. Some winter tows south of Australia have been made. The SO-CPR Survey has already identified two major changes in zooplankton composition in eastern Antarctic waters. The first was in the sea ice zone ( SIZ) around year 2000 when smaller zooplankton became more dominant instead of Antarctic krill. The second change occurred in 2004/05 north of the SIZ when pelagic foraminiferans exceeded 50% of the numerical abundance instead of the 2% long term average, replacing Oithona as the dominant species. Such changes in food size and type could have a major impact on the survival of higher predators.
|
/>