Algae bloom hotspot near Fraser is a fish feeding magnet

THE seas around the Fraser Coast region have been identified as an algae bloom hotspot and fish feeding magnet by researchers at the University of Southern Queensland and Griffith University.

Caused by ocean upwelling, a spectacle that involves the wind driving nutrient-rich water towards the ocean surface, the phenomenon plays a crucial role in the fishing industry by producing a readily available food source for yellow fin tuna and other marine species.

USQ associate professor in climatology Joachim Ribbe, PhD research student Daniel Brieva and Griffith University scientists have been able to identify, document and name the Southeast Fraser Island Upwelling System for the first time.

In their recently released academic paper, titled Is the East Australian Current Causing a Marine Ecological Hotspot and an Important Fisheries near Fraser Island, Australia?, the scientists show that the strengths and variability of the current is the main cause of this upwelling system.

Dr Ribbe said on average about eight algae blooms occurred each spring/summer season, occupying large areas of the Continental Shelf south-east of Fraser Island.

"The blooms cover an area about the size of Hervey Bay or about 2000 to 3000sq km," he said.

"Each bloom lasts about one week. Algae only bloom if nutrients and light are available.

"Usually, the surface ocean is low in nutrients but ocean upwelling delivers nutrient-rich water from deeper parts of the ocean back to the surface.

"Basically, ocean upwelling is fertilising the surface ocean and consequently plants start to grow and become available to the ocean food chain."

Dr Ribbe said the high marine productivity appeared to support a valuable fisheries area.

"This key ecological area located south-east of Fraser Island is one of eight along the east coast of Australia. The surface ocean waters to the east of Australia are usually characterised by very low marine productivity. The supply of nutrients in very distinct regions leads to very high marine productivity."

Dr Ribbe said more work was needed to investigate the biodiversity of the region and the overall impact the algae blooms were having on the ocean environment.

University of Southern Queensland associate professor Joachim Ribbe lowers research equipment into water near Fraser Island.
University of Southern Queensland associate professor Joachim Ribbe lowers research equipment into water near Fraser Island. Jocelyn Watts