'Bug' biomarkers used to assess water quality

As the most densely populated catchment in Australia, Port Phillip Bay faces many environmental concerns regarding water quality and pollutants. These issues often impact both the human, and wildlife populations that depend on its diverse ecosystems.

The Centre for Aquatic Pollution, Identification and Management (CAPIM) is a scientific collaborative research organisation based at Melbourne University, and focuses on identifying and addressing aquatic pollutants, as well as their impacts on living organisms and ecosystems.

Dr Sara Long, an ecotoxicologist who works with CAPIM at the Bio21 Institute as part of the Hoffmann Group, studies metabolites to identify biological changes as a result of chemical exposure. Metabolites are small molecules present in biological materials and are the product of metabolic chemical reactions and involved in many cellular processes. These can be used to measure specific biological changes within individuals, which may reflect current environmental conditions.

Aquatic organisms such as macroinvertebrates, which include species of worms, snails, spiders, mites, crustaceans and insects, show varying levels of sensitivity to different toxins and toxin levels. As a result, individual species can be assigned a pollution sensitivity rating, and then used as biological markers.

Dr Long hopes to develop more effective ‘bug biomarkers’ or specific molecular, cellular and physiological responses, or behavioural changes, when exposed to certain chemicals. This is important for not only identifying the presence of a toxin but also its concentration within the environment. Such information may be used as an early warning indicator that organisms are under stress, before broader signs of ecosystem degradation occur.   

“The challenge is to develop new methods that can be used in CAPIM biomonitoring programs”, said Dr Long.

Associate Professor Vincent Pettigrove, Chief Executive Officer for CAPIM and Principal Research Fellow at The University of Melbourne, also believes that metabolites show great promise as biomarkers for assessing stress in aquatic organisms.


“A major part of our success as a research group is that we have successfully communicated our work to agencies that will adopt it”, said Associate Professor Pettigrove.


“A major part of our success as a research group is that we have successfully communicated our work to agencies that will adopt it”, said Associate Professor Pettigrove.

CAPIM aims to locate pollution hotspots, and advance approaches for integrated catchment management by developing better technologies for detection and monitoring. Through working with environmental management authorities, such as Melbourne Water, the Environmental Protection Agency, as well as the Department of Environment, Water, Land and Planning, appropriate mitigation approaches may be used to improve ecosystem health and promote future sustainability.

“Our unique approach to identifying the priority issues in catchments that are affecting aquatic ecosystems and other values is also being considered for inclusion in the State Environmental Protection Policy Waters of Victoria, which is currently under review”, he said.

Dr Long’s most recent findings along with the practical use of biomarkers in catchment assessments for herbicide and insecticide toxicity within ecosystems in, and around Port Phillip Bay, were just some areas discussed during a two-day symposium hosted at the Bio21 Institute on the 1st and 2nd of December, 2015.

The symposium was split into a research summit, showcasing current research projects of staff and students, and a participant’s forum focussing on applied outcomes of these research projects.

Pettigrove said the biannual symposium was a major opportunity to communicate new findings with practical applications.

By Esther Lloyd