Ecology & Environment

Ecology & Environment is about understanding freshwater fish.

This research theme enhances capacity to effectively and efficiently deliver large-scale restoration initiatives underpinned by fundamental ecological knowledge of freshwater fish and ecosystems. The theme builds new tools to measure the health of native fish populations, advances implementation of next-generation tools and contributes new knowledge to society.

Theme Leader: Dr Jason Thiem

Impact highlights

  • Improving insights of environmental monitoring, facilitating improvements in fish species abundance, diversity and condition.
  • Development and deployment of robust field tools, such as the use of eDNA, to improve mapping of threatened species distributions.
  • Identification of priority habitats, growth patterns, migration pathways and recruitment sources of native fish using fish tracking and otolith microchemistry.

Research focus

  • Engineering statistical tools to measure and track the health of fish populations, using critical biological indicators, at multiple spatial and temporal scales.
  • Deploying modern field and lab methods to improve the accuracy and efficiency of monitoring surveys, such as incorporating environmental DNA.
  • Application of innovative fish tracking techniques, including animal-borne electronic tags and fish ear bones, to inform effective and efficient use of water resources.

Current projects

Event-based intervention research

We evaluate native fish responses to delivered and natural flow events over the short-term (e.g. fish movement, body condition and spawning). Our research drives adaptive management of water planning and delivers the knowledge required to maximise benefits of public investment. Find out more about flows hereProject Lead: Dr Jason Thiem

Basin Plan Environmental Outcomes Monitoring

This large-scale monitoring program provides critical data on the health of native fish populations. NSW DPI has established a series of innovative analytical indices that can be used to track the effectiveness of conservation actions into the future. For more information about BPEOM in general, visit the MDBA website. Project Lead: Dr David Crook

Innovative technology

We use electronic tags to track long-distance movements of fish. We also use ear bones (otoliths) to determine where a fish was spawned and compare growth rates between different. This information helps determine the distribution of species throughout NSW, including critical habitats and movement corridors essential for population persistence. Project Lead: Dr Jason Thiem

Environmental DNA assay development for detecting threatened species

Analysis of environmental DNA (eDNA) – the DNA that fish leave behind in the water – can allow fish to be detected without need to capture them. The species of interest are traced using a specially-designed test, known as an assay. NSW DPI is developing a range of assays and laboratory experiments on important threatened and recreational species to enable better understanding of their abundance and distribution. Project Lead: Dr Meghan Duncan

Threatened species

Specialist fish species have distinct environmental requirements. NSW DPI research elevates understanding and management of these species, to secure their population sustainability into the future. Our focus is on expanding the range, abundance and genetic diversity of species such as Macquarie perch, endemic crayfish and eastern freshwater cod. Our methods include wild egg collection, captive breeding programs, restocking and translocations. Project Lead: Dr Gavin Butler

Key publications

  • Miles, N. G., Butler, G. L., Diamond, S. L., Bishop, D. P., van der Meulen, D. E., Reinfelds, I., & Walsh, C. T. (2018). Combining otolith chemistry and telemetry to assess diadromous migration in pinkeye mullet, Trachystoma petardi (Actinopterygii, Mugiliformes). Hydrobiologia 808:265-281.
  • Zampatti B. P., Fanson B., Baumgartner L. J., Butler G., Brooks S., Crook D. A., Doyle K., King A., Koster W. M., Maas R., Sadekov A., Scott P., Strawbridge A., Thiem J. D., Tonkin Z., Wilson P., Woodhead J., Woods R. (In Press). Population demographics of golden perch (Macquaria ambigua) in the Darling River prior to a major fish kill: a guide for rehabilitation. Marine and Freshwater Research.
  • Rourke, M.L., Fowler, A.M., Hughes, J.M., Broadhurst, M.K., DiBattista, J.D., Fielder, S., Wilkes Walburn, J. and Furlan, E.M. (2021). Environmental DNA (eDNA) as a tool for assessing fish biomass: A review of approaches and future considerations for resource surveys. Environmental DNA.
  • Stocks, J.R., Davis, S., Anderson, M.J., Asmus, M.W., Cheshire, K.J., van der Meulen, D.E., Walsh, C.T. and Gilligan, D.M. (2021). Fish and flows: Abiotic drivers influence the recruitment response of a freshwater fish community throughout a regulated lotic system of the Murray‐Darling Basin, Australia. Aquatic Conservation: Marine and Freshwater Ecosystems.
  • Wright D., Zampatti B. P., Baumgartner L. J., Brooks S, Butler G. L., Crook D., Fanson B., Koster W., Lyon J., Strawbridge A., Tonkin Z., and Thiem J. D. (2020). Size, growth and mortality of riverine golden perch across a latitudinal gradient. Marine and Freshwater Research 71:1651-1661.
  • Stocks, J. R., Scott, K. F., & Gilligan, D. M. (2019). Daily age determination and growth rates of freshwater fish throughout a regulated lotic system of the Murray‐Darling Basin Australia. Journal of Applied Ichthyology 35:457-464.
  • Thiem J. D., Wooden I. J., Baumgartner L. J., Butler G. L., Forbes J., Taylor M. D., and Watts R. J. (2018). Abiotic drivers of activity in a large, free-ranging, freshwater teleost, Murray cod (Maccullochella peelii). PLOS ONE 13:e0198972.
  • Stoffels R. J., Weatherman K. E., Bond N. R., Morrongiello J. R., Thiem J. D., Butler G. L, Koster W., Kopf R. K., McCasker N., Ye Q., Zampatti B., and Broadhurst B. T. (2020). Stage-dependent effects of river flow and temperature regimes on the growth dynamics of an apex predator. Global Change Biology 26:6880-6894.
  • Thiem J. D., Baumgartner L. J., Fanson B., Sadekov A., Tonkin Z., and Zampatti B. P. (In Press). Contrasting natal origin and movement history informs recovery pathways for three lowland river species following a mass fish kill. Marine and Freshwater Research.