Changes to natural flow conditions in rivers in south-eastern Australia have contributed to the decline of many native fish species. Many agencies work together to deliver water for the environment (‘environmental water’) in Victoria to restore river health. This project explores how we can target environmental water delivery to enhance population connectivity to boost the genetic health of populations. Genetic diversity underpins individual health and the capacity for populations to adapt to changes in their environment. Effective delivery of environmental water relies on understanding the connectivity of fish populations and the links between flows in rivers and processes which help maintain genetic health, including dispersal and recruitment dynamics.

This project uses genomic tools to address key knowledge gaps in fish ecology for five species (Murray Cod, Golden Perch, Australian Grayling, Australian Smelt and Common Galaxiid). Fin clips will be sequenced for many thousands of markers spread throughout the genome (yielding a representative subset of an individual’s complete set of DNA).

The Murray Cod, an iconic Australian native fish

Fish samples in the laboratory which will be used to explore genetic health.

Analysing the genetic make-up of individuals can demonstrate relationships between populations and individuals at different locations and tells us about how connected rivers are. This will help inform the design of environmental watering strategies, including the appropriate spatial scale, and can also tell us how watering events can improve the genetic health of populations.

This analysis of the genetic make-up of fish can also provide insights into the:

  • relative influence of local versus non-local recruitment
  • contribution of stocking to recruitment
  • number of breeding fish contributing to recruitment events
  • genes linked to climate, growth rate or exploratory behaviour.

This project is a collaboration between ARI, DELWP, La Trobe University, University of Melbourne, North Central Catchment Management Authority, Goulburn Broken Catchment Management Authority, South Australian Research and Development Institute, and New South Wales Department of Primary Industries.

For more information contact: Katherine.Harrisson@delwp.vic.gov.au (Project Lead, ARI/ La Trobe University) or Zeb.Tonkin@delwp.vic.gov.au (ARI)

The following fact sheet provides more details: