Oral Presentation Australian Society for Limnology Congress 2013

Movement behaviours of a riverine population of the threatened Macquarie perch during the spawning season  (#70)

Wayne Koster 1 , David Dawson 1 , John Morrongiello 2 , David Crook 3
  1. Department of Environment, Land, Water and Planning, Arthur Rylah Institute, Heidelberg, VIC, Australia
  2. CSIRO, Hobart, Tasmania, Australia
  3. Charles Darwin University, Darwin, Australia

Movement is an important and often complex component of the life histories of freshwater fish. Understanding movement behaviours is therefore critical to the development of strategies to conserve fish populations. The Macquarie Perch Macquaria australasica is a threatened freshwater fish species that has undergone a major decline in range and abundance. Whilst there is good ecological information for populations that have become established in artificial impoundments, substantial gaps exists in our knowledge of remaining riverine populations. A synchronised upstream spawning migration during spring-early summer has been documented for impoundment populations, with fish spawning in the lower reaches of inflowing streams. Whether riverine populations exhibit similar synchronised migratory behaviour during the spawning season is unclear. In this study, radio-telemetry is used to test the hypothesis that riverine Macquarie Perch exhibit synchronised migrations to specific river reaches during the spawning season. The results of the research show that the movement behaviour of riverine Macquarie Perch was complex and non-synchronous. Fish occupied restricted home ranges, undertook occasional local upstream and downstream moves coinciding with flow variations, but there was no evidence of movement of multiple fish to specific locations. These results suggest that management of riverine populations cannot necessarily be based on the behaviour of lacustrine populations, and highlights the need to consider population-specific variation in behaviours in management of threatened species.