Click here to access the Bay OK Geographe Gardeners Resource Kit

News

Science saving Black Bream

22 August, 2019

Seven years of Black Bream research is helping to better manage this popular recreational fishing species in the Vasse-Wonnerup.

Speaking at The secret life of Black Bream event last week, Murdoch University’s Dr James Tweedley presented his findings on the unique biology, ecology and behavior of Black Bream.

The Black Bream research, which is funded through the Revitalising Geographe Waterways program and Murdoch University, and supported by GeoCatch, is increasing our knowledge about what conditions support recruitment and a sustainable fishing stock.

“Because they complete their life cycle in the estuary, in that they are born, reproduce and die there, they are a good ecological indicator of estuary health,” he said.

“Every Black Bream population is genetically distinct, which means that once you lose Bream out of a system you can’t get it back.”

Murdoch Honours student, Richelle McCormack, also presented her research on what influences Black Bream movement through the fish gates at the Vasse surge barrier.

“Black Bream are more likely to pass through the fish gates during low flows and when the water on both sides is equalised,” she said.

Researchers and managers are working closely together to ensure that the local community has access to the latest science. This science has also been used in the review of the Surge Barrier operations to ensure fish passage has been considered in updating operational guidelines.

“It was wonderful to see so many community members who care about fish to turn up and learn about their populations,” said Dr James Tweedley.

“Community stewardship is critical to the survival of Black Bream in the Vasse-Wonnerup, as well as collaboration between researchers and managers.”

The secret life of Black Bream was hosted by GeoCatch as part of the Revitalising Geographe Waterways program, which aims to improve water quality, waterway health and management of Geographe waterways.

Fun facts about Black Bream:
• They can live for 30 years, grow to 60cm and weigh up to 4kg
• Are hermaphrodites until they reach 15cm
• Age is determined by counting rings in their ear bones
• More likely to be found near man-made structures in the Vasse-Wonnerup
• On average, moved 2.7 km per day, with one fish swimming as far as 45 km in 24 hours