SCAR SO-CPR Survey

Graham Hosie - Director AAD, Tasmania

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 (Department of Sustainability, Environment, Water, Population and Communities) to map the spatial-temporal patterns of zooplankton biodiversity and then to use the sensitivity of plankton to environmental change as early warning indicators of the health of the Southern Ocean (Hosie et al. 2003).

It also serves as reference for other monitoring programs such as CCAMLR's Ecosystem Monitoring Program C-EMP, and the Southern Ocean Observing System.

Fourteen ships from eight countries have participated in the Survey to date: Australia, Japan, Germany, New Zealand, USA, Russia, Brazil and Chile providing a near circum-Antarctic Survey. The United Kingdom, through collaboration between SAHFOS and the British Antarctic Survey oversees an additional survey in the Scotia Sea. Brazil and Chile also represent the South American Census of Antarctic Marine Life consortium of Brazil, Uruguay, Argentina, Chile, Peru, Ecuador and Venezuela, established during the International Polar Year.

The consortium supported by the Brazilian and Chilean Antarctic programs, and the US AMLR programme conduct CPR tows across Drake Passage, which complement the tows conducted by the UK. Russia (AARI) has provided the few CPR in the Amundsen and Bellingshausen Seas, an area where biological sampling is poor. New Zealand (NIWA) conducts annual tows south to the Ross Sea. Germany (AWI) works south of Cape Town. The highest concentration of CPR tows is in the region south and west Australia, conducted by Japan (NIPR and TUMSAT) and Australia, led by the AAD and supported by AusCPR.

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.

Preparing the CPR on board TS Umitaka Maru (Graham Hosie)

The silks are processed in the laboratory by trained plankton taxonomists in Australia, Japan and New Zealand. The UK samples are processed at SAHFOS. 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 5 nmile.

CPR Tows conducted between 1991-2008 (AADC Map 13481)

With the support of AusCPR, phytoplankton counts have been conducted on selected Australia tows since 2007. Approximately 50 tows are made each year, although more than 80 tows were completed in 2007-08 for CAML. Approximately, 150,000 nautical miles of tracks have been sampled since 1991, producing more than 30,000 samples for nearly 250 zooplankton and 80+ phytoplankton taxa coupled with environmental data. Most data come from the October to April period, the main period of shipping activity. Some winter tows south of Australia have been made.