Full Title
Spawning and recruitment ecology of golden perch
Student
Clayton Sharpe
Supervisors
Angela Arthington and Brad Pusey (Griffith University), Shaun Meredith (MDFRC)
Funding Body
Victorian Fisheries Revenue Allocation Committee (FRAC)
Duration
February 2004 to February 2007
Outcomes
PhD
Summary
Background
Due to range and abundance reductions and certainly due to their recreational popularity, hundreds of thousands of hatchery reared golden perch (Macquaria ambigua Richardson 1845) are annually liberated into rivers of the Murray-Darling Basin to augment natural recruitment and sustain recreational fisheries (Rowland 1996). The principal objective of this research program is to present a conceptual model of natural golden perch recruitment ecology based upon empirical field observations and experiments, aimed at balancing conjecture and quantifying existing assumptions relating to this species life-history strategies and recruitment ecology. Greater understanding of the ecological processes contributing to survival and recruitment of golden perch is required to discover how aquatic ecosystems might be managed differently to allow rebuilding of golden perch populations and fish communities through improved natural recruitment.
Methods
- Measure indices of golden perch reproduction in wild populations at three different locations (catchments) affected by varying flow regimes and river regulation scenarios.
- Determine developmental patterns, growth rate, prey availability and diet of larval and juvenile golden perch between floodplain and riverine habitats.
- Correlate sexual development, growth rate and age with environmental parameters such as habitat, flow, prey availability and temperature.
Objectives
- To decouple the role of flow, temperature and seasonality as stimuli for golden perch reproduction.
- To compare patterns of reproductive effort for populations between spawning events during flood and non-flood years.
- To examine the timing, habitat and duration of spawning between populations (catchments) affected by different flow regimes.
- To examine ontogenetic patterns of dispersal and habitat use for larval and juvenile golden perch.
- To examine/compare growth rates, diet and other recruitment factors for golden perch larvae/juveniles inhabiting floodplain and river channel habitats.
Main Findings
Golden perch spawned in the main channel of the Darling River (at Menindee) in response to a flood event during 2004 (after a long period of no flow). Downstream of Menindee, golden perch spawning was delayed, and pronounced in response to a within channel flow event. Golden perch in the upper-Murray (upstream of Yarrawonga) population failed to spawn during 2004. Larvae and juvenile golden perch from the floodplain Menindee Lakes and Darling River have been sampled monthly for 12 months, with age, growth, diet, and habitat data obtained; awaiting analysis.
