The SCAR Southern Ocean Continuous Plankton Recorder (SO-CPR) Survey was established in 1991 by the Australian Antarctic Division,of Environment, Water Heritage and the Arts, 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 Southern Ocean and Antarctic monitoring programs.
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon (ζῴον), meaning "animal", and planktos (πλαγκτός), meaning "wanderer" or "drifter". Individual zooplankton are usually microscopic, but some are larger and visible to the naked eye.
Plankton are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current. The individual organisms constituting plankton are called plankters. They provide a crucial source of food to many large aquatic organisms, such as fish and whales.
The Southern Ocean, also known as the Antarctic Ocean or the Austral Ocean, and the "Southern Icy Ocean".</ref> comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. As such, it is regarded as the fourth-largest of the five principal oceanic divisions: smaller than the Pacific, Atlantic, and Indian Oceans but larger than the Arctic Ocean. This ocean zone is where cold, northward flowing waters from the Antarctic mix with warmer subantarctic waters.
Several countries collaborate in the survey providing vessels to tow Continuous Plankton Recorders (CPRs) in a near circum-Antarctic survey. Tows conducted between Hobart and the French Antarctic station Dumont d’Urville are also conducted in collaboration with the IMOS Australian Continuous Plankton Recorder Survey. The SO-CPR Survey is supported by the Scientific Committee on Antarctic Research and its Expert Group on Continuous Plankton Research, which helps promote and develop the survey.
The Continuous Plankton Recorder (CPR) Survey is one of the longest running marine biological monitoring programmes in the world. Started in 1931 by Sir Alister Hardy and Sir Cyril Lucas, the Survey has provided marine scientists with their only measure of plankton communities on a pan-oceanic scale. Today the CPR Survey is operated by the Marine Biological Association(MBA), located in Plymouth, UK. Uniquely, the CPR Survey’s methods of sampling and plankton analysis remain unchanged since 1948, providing a spatio-temporally comprehensive > 60 year record of marine plankton dynamics.
The Antarctic is a polar region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately 32 to 48 km wide varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent is the surface area of the Antarctic continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System. Biogeographically, the Antarctic ecozone is one of eight ecozones of the Earth's land surface.
Hobart is the capital and most populous city of the Australian island state of Tasmania. With a population of approximately 225,000, it is the least populated Australian state capital city, and second smallest if territories are taken into account. Founded in 1804 as a British penal colony, Hobart, formerly known as Hobart Town or Hobarton, is Australia's second oldest capital city after Sydney, New South Wales. Prior to British settlement, the Hobart area had been occupied for possibly as long as 35,000 years, by the semi-nomadic Mouheneener tribe, a sub-group of the Nuennone, or South-East tribe. The descendants of these Aboriginal Tasmanians often refer to themselves as 'Palawa'.
The CPRs are towed from research and supply vessels. The CPR is towed at about 10 metres below the surface and for about 450 nautical miles (830 km) per tow. The plankton enters a small opening in the device and is trapped and preserved between two layers of silk mesh. These vessels also collect at the same time underway data such as sea surface temperature, salinity, fluorometry, light and other oceanographic-meteorological parameters. All plankton in five nautical mile (9 km) 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-nautical-mile (9.3 km).
Sea surface temperature (SST) is the water temperature close to the ocean's surface. The exact meaning of surface varies according to the measurement method used, but it is between 1 millimetre (0.04 in) and 20 metres (70 ft) below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a short distance of the shore. Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass. Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth's oceans. Tropical cyclones can also cause a cool wake, due to turbulent mixing of the upper 30 metres (100 ft) of the ocean. SST changes diurnally, like the air above it, but to a lesser degree. There is less SST variation on breezy days than on calm days. In addition, ocean currents such as the Atlantic Multidecadal Oscillation (AMO), can effect SST's on multi-decadal time scales, a major impact results from the global thermohaline circulation, which affects average SST significantly throughout most of the world's oceans.
Salinity is the saltiness or amount of salt dissolved in a body of water, called saline water. This is usually measured in . Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water.
Antarctic krill is a species of krill found in the Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre. It feeds directly on minute phytoplankton, thereby using the primary production energy that the phytoplankton originally derived from the sun in order to sustain their pelagic life cycle. It grows to a length of 6 centimetres (2.4 in), weighs up to 2 grams (0.071 oz), and can live for up to six years. It is a key species in the Antarctic ecosystem and is, in terms of biomass, probably the most abundant animal species on the planet.
Approximately 40-50 tows are made each year. More than 80 tows were completed in 2007-08 International Polar Year in support of the Census of Antarctic Marine Life. 135,000 nautical miles (250,000 km) 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. Few ships operate in the region during winter but some winter tows south of Australia have been made.
Use of the SO-CPR data for research purposes is encouraged. Data are made available soon after the CPR samples are processed. Data are held at the Australian Antarctic Data Centre and at the SCAR Marine Biodiversity Information Network.
