Shellfish become spies to help improve aquatic ecosystems

The three-year partnership between Murdoch University's Harry Butler Institute and the Alcoa Foundation will involve three species of mussels, fitted with sensors and used at six monitoring stations across the region.

Mandurah Marina, Murray River, Serpentine River, Lane Poole Reserve, Harvey Dam and Waroona Dam will serve as the monitoring locations.

Led by research fellow, Dr Alan Cottingham, the project aims to understand impacts and causes of fish kills or mass mortality events (MMEs) and discover how to reduce their frequency and severity.

Dr Cottingham said mussels operate like secret spies, closing at the first sign of stress brought on by water quality issues. Attaching sensors to the mollusc's shell to indicate when they close will provide an early warning sign for potential problems.

"We are using a 'canary in a coal mine' theory and applying technology to help us identify ecosystem changes that may result in far greater issues such as fish kills and toxic algal blooms," he said.

"Bindjareb Djilba (the Peel-Harvey Estuary) is the largest and most diverse estuary in the South West. However, the estuary, its rivers and catchments are also among the most impacted by our drying climate and modification by human activity.

"Consequently, fish kills occur most years in the estuary. However, the causes are often unknown."

Alcoa Foundation President Caroline Rossignol said the water monitoring project aligned with a key foundation objective - to invest in projects that contribute to improved outcomes in biodiversity conservation and climate change mitigation and adaptation.

"We are excited to support the Harry Butler Institute on this important project and look forward to learning how the mussel monitoring stations can assist in improving the health of waterways, not just in Western Australia, but potentially around the world," she said.

The region's waterways contain several critically endangered and vulnerable species, along with being an important spawning and nursery grounds for recreationally and commercially important fish and crustaceans.

This made the project particularly important for South West waterways, Dr Cottingham explained.

"Not only are MME events distressing for recreational water users and the local community, but they can have broader reaching economic impacts too," he said.

The region is facing some of the nation's most significant declines in streamflow. Finding ways to support earlier intervention are considered critical to maintaining healthy ecosystems.

Over the course of the next three years, six stations will be deployed, with each station linked to school and Aboriginal ranger groups.

The students will be trained to undertake initial assessments when poor water quality events occur. Their work will be monitored by the Department of Water and Environment Regulation (partner in the project's delivery).

Dr Cottingham said engaging with local Aboriginal rangers would allow for further understanding of the land and waterways throughout the project.

He added that students participating from local schools would have the opportunity for hands-on aquatic learning to accompany their schooling.

The project officially launched on Wednesday, October 18 at Mandurah Ocean Marina.