Non Technical Summary

Summary

Variation in the otolith chemistry of golden perch ( Macquaria ambigua ) from inland Australian rivers

Analysis of the chemical composition of otoliths (ear bones) of fish can be used to distinguish between groups that have lived in different environments. In extensive river systems such as the Murray-Darling, this is useful for determining where fish have originated from or have moved to during their lives.

In this study, the chemical compositions of the otoliths of golden perch ( Macquaria ambigua ) from several locations throughout the Murray-Darling system were measured. Variation in otolith chemistry was examined between rivers and between sites within a single river. The influence of variation between years and between size classes of fish was also examined.

Significant differences in otolith chemistry were found between fish from different rivers. Within rivers, variation was less pronounced and discrimination between sites was less accurate. Differences between years and between size classes of fish partially confound patterns of spatial variation.

The results of this study demonstrate that with careful experimental design, it may be possible to identify sources of golden perch based on otolith chemistry. This is significant for future studies aimed at determining the important spawning and recruitment locations for golden perch. It is also important for future studies aimed at determining the success and impact of the golden perch stocking program.