James O'Dwyer

James O'Dwyer

Flows for fish: Using water flow to promote connectivity, recruitment and genetic diversity for Australian fish species

Extensive alteration of natural river flows has contributed to strong declines in Australian fish species. In response to declining river health, governments have invested substantially in delivering environmental flows to restore natural flow conditions. As water is a scarce resource, cost effective and efficient delivery of environmental flows is essential to justify such substantial investments. James is using genomic tools to better understand the relationship between flows and the processes that shape genetic diversity in native fish. High genetic diversity is critical as it underpins the health of individuals and the capacity of populations to adapt to environmental change. James is exploring how spatial and temporal variation in flows influence fish dispersal and recruitment, and what the resultant impact is on genetic diversity. Hundreds of genetic samples from larval, juvenile and adult life-stages of Common Galaxias, Tupong, Australian Grayling, and Murray Cod are being analysed to establish how connected populations are, and whether genetic diversity is being passed on to successive generations effectively. As well as providing new insights into fish ecology, this research will increase knowledge on how watering events can improve the genetic health of populations. This will help inform the design of environmental water releases to maximise the benefits to native fish.


La Trobe University


Primary Supervisor
  • Dr Katherine Harrisson (La Trobe University, Arthur Rylah Institute for Environmental Research)
  • Zeb Tonkin (Arthur Rylah Institute for Environmental Research)


January 2018 to January 2021