ILWS - Charles Sturt University
ILWS - Charles Sturt University

Evaluation of survival behaviour of fish to inform re-stocking programs (2020-2021)

Funding

Department of Primary Industries, Recreational Fishing Trust. $48,880

Investigators/ Researchers

Dr Raf Freire, Dr Paul Humphries, Leia Rogers, L. (PhD student), Cameron Westaway, (NSW Fisheries) & Dr Keller Kopf, Charles Darwin University)

Research Theme

Biodiversity Conservation

Description

Natural populations of freshwater fish in Australia are estimated to have declined by more than 80% in most areas of the Murray-Darling. In response to this decline in fish populations, re-stocking programs are an important management tool intended to boost wild fish populations and support recreational fisheries. Currently millions of fish are being released in NSW waters. However many of these fish fail to survive for any length of time due to an inability to find food, shelter or avoid predation. It has been known for some time that in the hatchery environment, fish lose much of their natural “wild” behaviour which impairs their chances of surviving after release.

This project has two objectives:

  • to determine the age hatchery fish lose their natural "wild" behaviour and adopt the "domestic" behaviour
  • to examine the preference and speed of selection of shelter at different ages and, in consultation with Narrandera Fisheries, assess any new rearing practices for their effect on fish behaviour.

The project supports the work of ILWS PhD student Leia Rogers who is undertaking tank-based behavioural tests with Murray cod and Golden perch at CSU's new Aquatic Research Facility on the Albury-Wodonga campus at Thurgoona. Once these tests are completed, individual fish will then be released into a large tank with five distinct areas providing varying amounts of shelter to determine how fish are likely to respond when released into different habitats.

Outcome

This research is expected to:

  • reveal the best age to release fish, based on the timing of when they lose their natural "wild" behaviours, to enhance their chances of post-release survival
  • provide recommendations on how hatchery management practices influence behaviour critical for survival
  • provide the foundation for future hatchery and wild fish research which will evaluate the survival of hatchery released fish in different conditions; and test new and emerging approaches to maximise the success of re-stocking programs.

Contact

Dr Raf Freire
Albury-Wodonga Campus

Email

November 2020