Morphological and chemical analysis of archaeological fish otoliths from the Lower Murray River, South Australia

We analysed otoliths from excavations along the Lower Murray River (n=24), dating from the mid- To late-Holocene period. We identified the species, and estimated the size and age of fish. The potential habitat that fish used throughout their life was estimated from chemical information in the otoliths. The majority of the fish (identified as Maccullochella peelii n=22 and Macquaria ambigua n=2) were caught in freshwater environments during the warm season, and had grown to an age and size indicative of sexual maturity. These observations accord with Ngarrindjeri oral tradition concerning sustainable management strategies. Data indicate that M. peelii grew to a significantly larger size than present fish; historical data suggests this size reduction may be the result of European fishing practices, introduced species and habitat degradation. The study demonstrates the unique nature of otoliths and their potential for investigating Indigenous subsistence strategies.