Australian plankton survey

A new plankton survey will provide critical information on the current status of these important microscopic marine plants, in Australian waters.

Much of the Integrated Marine Observing System (IMOS) will be dependent on a suite of high technology instruments such as robotic floats, autonomous profiling gliders and mooring systems. However, IMOS will also use 1930s technology in the form of continuous plankton recorders (CPR) towed behind ships, to monitor changes in plankton patterns.

Plankton are particularly sensitive to subtle changes in their environment, which makes them useful early warning indicators of the health of ocean systems. CPRs have proven to be the most cost effective and reliable methods for rapidly and repeatedly surveying large ocean systems. They have identified significant changes in the plankton of the North Sea, North Atlantic and North Pacific, long before indications were observed at other levels of the food web. The Southern Ocean CPR (SO-CPR) Survey, developed by Australia and Japan, has been running since 1991 and has also detected substantial changes in the plankton.

There have been few plankton studies or monitoring programmes in Australian waters. Through IMOS, however, we have received AU$1.7 million over five years to support two new Australian CPR (AusCPR) runs — across the Tasman Sea, and between Hobart and the French Antarctic station Dumont d’Urville.

The Tasman Sea route will traverse the East Australia Current (of Finding Nemo fame). This region is forecast by global climate models to experience a high degree of warming in the Southern Hemisphere over the 21st century. For the Southern Ocean route we will use the French resupply ship l’Astrolabe, which makes numerous runs each season from October to March. This route will also support the SO-CPR Survey. AusCPR will also complement existing monitoring programmes on these routes that collect information on phytoplankton (via pigments), carbon dioxide, and chemical and physical oceanographic patterns.

It is hoped that AusCPR will forge strong collaborative links with the Sir Alister Hardy Foundation for Ocean Science, which coordinates the northern hemisphere surveys, and with the SO-CPR Survey, to produce a more effective global plankton monitoring programme.

Over the next five years AusCPR will produce unprecedented knowledge of the composition, distribution, seasonality and relationship of plankton to other oceanographic patterns in Australian waters. In the years to come, this information will provide a rare baseline in the region in order to assess the effects of climate change on the marine food web. The first tows are expected to commence by the end of 2007.