13 July 2012 Changes in water quality

Image: AIMS

Water quality on the Great Barrier Reef (GBR) is critically important for a healthy ecosystem. When water quality deteriorates on the GBR we see deterioration of important habitats including coral reefs and seagrass beds, which are home to many species of reef fish, crustaceans and marine mammals.

Senior Research Scientist at the Australian Institute of Marine Science (AIMS), Dr Britta Schaffelke, will discuss changes in water quality on the GBR over recent decades, as well as the processes that drive them, in her presentation at the 12th International Coral Reef Symposium.

Dr Schaffelke leads the Water Quality & Ecosystem Health research team at AIMS, which has the longest available dataset on water quality for the GBR (1989-2010). This has allowed Dr Schaffelke and her team to correlate changes in water quality with marked weather events and human activity in adjacent catchments.

"The long-term data from the inshore GBR lagoon show that water quality variability is mainly driven by seasonal processes such as river-floods and strong winds," says Dr Schaffelke. "Floods and cyclones are particularly important drivers of water quality, causing significant disturbance to inshore ecosystems such as coral reefs and seagrass beds."

"Our analysis shows that water quality dropped significantly during the late 1990s and early 2000s, a period that coincided with very high rates of vegetation clearing on the adjacent land, and three major river floods."

"This is the first direct evidence that catchment activity affects marine water quality. Future improvements in GBR catchment management are expected to improve inshore water quality, but we propose that the reduction of sediment and nutrients loads during floods and cyclones, for example through better control of soil erosion, should be a priority."

Ongoing monitoring of water quality on the Great Barrier Reef will continue to provide key information about an important aspect of the resilience of the complex ecosystem that makes up this unique, natural wonder.

Dr Britta Schaffelke will present ‘Water quality variability in the inshore Great Barrier Reef lagoon' on Friday 13th July, 10:15, Plenary Hall 2 (Session: 21B Enhancing coral reef resilience through management of water quality)

For more information:

Dr Britta Schaffelke, Senior Research Scientist, 0427 029 464, b.schaffelke@aims.gov.au

Wendy Ellery, AIMS media liaison, 0418 729 265, w.ellery@aims.gov.au