Battery-powered acoustic tags to boost mulloway research

Battery-powered acoustic tags will be fitted to juvenile mulloway as part of a research project to help improve restocking programs.

The 18-month project is being funded with more than $24,500 from the Recreational Fishing Saltwater Trust and run by the University of NSW.

A total of 40 juvenile mulloway - largely ranging in size from 20cm-80cm - will be tagged for the research in Botany Bay.

They will be fitted with 'pingers' that emit a series of electronic 'blips' that can be detected by a boat-based hydrophone and receiver. Each fish has a unique code, so it can be tracked individually.

Very little is known about key juvenile mulloway habitats in south-eastern Australia, or their daily and seasonal migration patterns, so this will hopefully reveal some of those secrets.

The study will also compare the movements of wild versus hatchery-reared mulloway within two different NSW estuaries.

The batteries in the pingers will be flat by June 2005. A large fishing competition will be organised just before that date to retrieve the pingers from the fish so they can be fitted with new batteries and re-used.

This study will build on another three-year project being undertaken by the University of NSW and funded by the Recreational Fishing Trust. The three-year project involved stocking mulloway fingerlings into Botany Bay and Smith's Lake, and is evaluating survival rates and gut contents of the fish.

The wild and hatchery-reared fish were released in March 2003 and will be captured on hook and line with the help of the St George-Sutherland Shire Anglers Club.

This is anglers' fees at work - all money raised by the NSW recreational fishing licence is placed into saltwater and freshwater trusts overseen by anglers and used to improve recreational fishing.