Biodiversity study in Kakadu’s wetlands

A team of researchers from Griffith University’s Australian Rivers Institute is taking part in a biodiversity survey of the waterways and wetlands in Kakadu National Park.
Tropical river scientists from across Australia are involved in the project, forming the Northern Australia hub of the National Environmental Research Program. The scientific team is working in collaboration with Kakadu National Park and the traditional owners on projects which aim to better manage and conserve the region’s unique wildlife and support sustainable livelihoods.Professor Stuart Bunn from the Australian Rivers Institute said there were several groups of researchers undertaking different types of work, including surveying for threatened freshwater sawfish, sampling estuarine fish, and collecting invertebrate and plant samples.”We are trying to get a better understanding of aquatic biodiversity patterns and the processes that sustain them in the park, so that we can minimise threats in the future,” Professor Bunn said.”These are highly connected ecosystems, and we aim to find out how important the connections are between the rivers, floodplains and estuaries. We want to know where the fish and other animals get their food and where the ‘hot-spots’ of production are which sustain the high biodiversity we see in these river systems.

The group sampling estuarine fish in the South Alligator River is using a variety of netting and trapping techniques to document patterns in fish size and abundance, and how this
varies between the wet and dry season in response to changes in flow and habitat.

“It’s fascinating how different the fish communities are on this trip compared to a wet season sampling trip earlier in the year. The group has collected several species which weren’t around during the wet, and the size and abundance of various species has also changed.

Another group is surveying Kakadu’s rivers to see how important it is as a habitat for the threatened freshwater sawfish and other estuarine species including the speartooth shark
and the northern river shark.

“This kind of work is not possible without effective collaboration,” Professor Bunn said.

“Parks Australia and traditional owners are working closely with the team, which comprises researchers from Charles Darwin University, Griffith University, the University of Western Australia, NT Fisheries, the Museum and Art Gallery of the Northern Territory and CSIRO.”

The knowledge gained from this project will be used to assess potential effects on northern Australia’s aquatic biodiversity caused by climate change, sea level rise and other threats.

It will also help inform management strategies to minimise the impact of these threats.