Monday 27 February2006

Creepy crawly crustaceans are set to help the Great Barrier Reef Marine Park Authority (GBRMPA) shed light on the declining quality of water entering the Marine Park.

Scientists will use the common mud crab to monitor pesticide concentrations as crabs exposed to pollutants often develop subtle cellular differences and may accumulate certain water quality toxicants.

GBRMPA Manager of Water Quality Research and Monitoring Dr David Haynes said this was a potential long-term indicator of temporal and spatial variation in inshore pollutant concentrations.

“Mud crabs can provide a sensitive, early warning of the presence of pollutants before conventional monitoring techniques can detect it,” he said.

“The presence of the pollutants has no affect on the edibility of the crabs. The toxins accumulate in the animal’s liver, which humans do not consume, and not the crab’s flesh that people do eat.

“This monitoring is just one of several components under the Reef Water Quality Protection Plan, a ten-year strategy to halt and reverse the declining quality of water entering the Marine Park.”

Adult male crabs, with a legal size of 170-200 mm carapace width, will be collected between March and May each monitoring year.

The crabs will be sourced from at least 10 coastal locations along the north Queensland coast between Torres Strait and Gladstone.

The monitoring involves separating the hepatopancreas tissue (the crab’s non-edible liver) from the crab’s carcass and analysing it for pesticides that tend to bioaccumulate in this organ.

This is just one of five types of monitoring under the Reef Water Quality Protection Plan, which focuses on land-based actions to improve land use practices within the Great Barrier Reef Catchment.

The plan aims to monitor and observe the amount of nutrients and sediment entering river systems flowing into the Great Barrier Reef, and develop strategies to address and halt the process.

A variety of evidence now clearly indicates exports of sediments, nutrients and pesticides from the catchments adjacent to the Great Barrier Reef have increased substantially over the last 150 years.

The Reef Water Quality Protection Plan Marine Monitoring Programme is run by the GBRMPA and funded by the Natural Heritage Trust. The Marine Monitoring Programme was designed and developed by the GBRMPA and is coordinated through the CRC Reef Research Centre on behalf of a consortium of research partners.

The consortium includes the Australian Institute of Marine Science, CSIRO, Queensland Department of Natural Resources and Mines, Queensland Department of Primary Industries and Fisheries, Queensland Environmental Protection Agency, Sea Research and The University of Queensland.