Looking like a leftover from a 1950’s sci-fi film, this instrument is still at the forefront of scientific research in our oceans. The Continuous Plankton Recorder (CPR) was first designed by British scientist, Sir Alister Hardy, in the mid 1920s and it made a radical development in how plankton – tiny crustaceans that are to be found worldwide – is surveyed.
Rather than spot net sampling, which can be inaccurate due to the unique patchy distribution and behaviour of plankton, the CPR is towed behind a ship and gathers samples continuously for up to 450 nautical miles. Between 1990 and 1995, the Australian Antarctic Division (AAD) took Hardy’s original design and slightly modified it, creating a Type II version that, while essentially very similar to Hardy’s original design, is more streamlined, built from marine-grade stainless steel (rather than phosphor bronze) and has an easier reload mechanism.
The instrument is now used on all AAD voyages to Antarctica, as well as in partnership with Japanese Antarctic vessels, and it has allowed scientists to compare data from both the northern hemisphere and the southern hemisphere. This data has shown some significant changes in the composition of plankton since the project began in 1991 – notably, there is a greater amount of smaller plankton compared to krill (particularly copepods).
The CPR forms an important part of measuring changes in ocean life, as well as the ocean’s physical conditions – and it is revealing critical information concerning climate change. Tasmanian-based scientists have led the world in Antarctic and Southern Ocean studies, and Hobart has become a hub in this vital field of research and education.