Kerang Lakes Fishery Improvement

The Kerang Lakes has a history of successful Murray cod and golden perch stocking resulting in improved fishing opportunities.

Fisheries Victoria commenced a project in 2012 titled: Inland 'reefs' to improve  recreational fishing in the Kerang Lakes with the desired outcomes to improve recreational fishing through: more abundant native species, better catch rates, bigger fish and better returns from stocking. A component of the project was to investigate the feasibility for habitat enhancement to improve recreational fishing for native stocked fish, golden perch and Murray cod.

A literature review was conducted to investigate native habitat requirements and to review case-studies of relevant fish habitat enhancement projects. The literature review found:

• Murray cod appear likely to be associated with areas supporting structural woody habitat, particularly in the lower 15% of the water column. Golden perch appear to have a broad range of habitat requirements in lakes and impoundments but are likely to be associated periodically with structural woody debris mid-water in less than 10 metres depth.
• Efforts in Australia to install freshwater fish habitat have generally focussed on adding large woody debris or rocks, resulting in increasing fish abundance in rivers, with a few projects extending their aims to enhancing recreational fishing. Little fish-habitat installation and enhancement has occurred in reservoirs and lakes, none of which are stand out successes for enhancing angling.
• Efforts overseas to enhance recreational fisheries by installing habitat are numerous and successful. Results include increasing abundance and survival of fish. A key learning from the international literature is that habitat enhancement is more successful in lakes with little naturally existing structure.

Two site-scoping visits of the Kerang Lakes were conducted and advice was provided on fit-for-purpose and cost-effective habitat designs, materials and locations that met the requirements of specific lakes.

Definitions, advantages, disadvantages and potential sources of materials were provided for two recommended habitat options in each lake including:

• Large woody debris and/or large rocks in Kangaroo Lake to aggregate golden perch and Murray cod for recreational fishers.
• Reefs of medium rocks or gabion rock blocks to enhance the survival of juvenile golden perch and Murray cod in Lake Boga.

Advice was provided on habitat specific site selection within the constraints outlined in the Carolane (2012) report. In Kangaroo Lake, this included a bank-based angler access option in the north-west corner and a boat-based angler access option in the southern end. In Lake Boga, the best location for habitat installation was identified with a GPS point.

The installation of artificial 'reefs' to enhance recreational fishing in lakes is highly innovative. It is recommended that the effectiveness of installed habitat be evaluated to determine whether it meets the desired objectives. Evaluation should collect data from the recreational fishery and method options are provided. These evaluation methods are cost-effective, engage anglers and inform the development of future projects about lake-habitat installation for recreational fishing purposes.

Further Information

For a copy of the Full Report please email: richard.rogala@vfa.vic.gov.au