Oral Presentation AFSS/NZFSS Joint Conference 2019

Patching knowledge gaps in Coorong ecosystem function, since European colonisation (#140)

Faith Coleman 1
  1. School of Health and Life Sciences, Federation University , Mt Helen , Victoria, Australia

The Coorong is Australia's largest wave-dominated estuary. It has captured Australians imaginations through books and movies such as Storm Boy. Unfortunately, like many similar estuaries, it has degraded substantially since European colonization.

The majestic, once highly productive estuary currently has one-tenth of its previous fisheries productivity. Key nursery areas for estuary-specific fish (such as Black Bream) in the South Lagoon, are filled with monosulfidic black ooze (MBO). Dinoflagellate and cyanobacterial blooms are prolific and higher-order aquatic plant species are disappearing from the system.

Environmental flows into the estuary have significantly improved the health of the North Lagoon and Mouth since the 2006-2009 drought. However, the health of the South Lagoon continues to decline.  

While there are many known ways to restore estuaries, restoration of this estuary is not helped by the significant debate and apparently opposing views, caused by shifting baseline understandings of how the South Lagoon functioned, prior to agricultural development, or how it has changed with various management interventions. Without clear goals, it is hard to know how to achieve them.

The Lakes and Coorong fishery have significant fisheries records, spanning several generations. They are keen to see if this data can be used to help patch the gaps in knowledge, so that the changes in South Lagoon ecosystem function can be mapped over time.

Over the next three years, I intend to work with the fishery, to answer some of these questions around changes in fish habitat over time, the previous water sources that supported these habitats, the differential ecology of the fish species involved and how the fish communities responded to changes in water management practices.