Seasonal dating using fish otoliths: Results from the Shag River Mouth site, New Zealand

Fish otoliths of Pseudophycis bachus(red cod) have been excavated from cult ural deposits at the site of Shag River Mouth in North Otago, New Zealand. We sectioned the otoliths and examined the annual and seasonal growth rings formed during the fishes' life and compared them with an extensive number of modern examples to determine the season in which they were caught in pre history. Using this method we estimated the seasons of prehistoric occupati on of specific cultural layers. Otoliths from the uppermost layer of the si te (layer 2) yielded a seasonal estimate of December-February whilst the ma jority of those from the main layer 4 shell midden yielded a series of Sept ember-November estimates. The results confirm earlier seasonal results dete rmined from oxygen isotope analysis of blue Mussel (Mytilus edulis aoteanus ). The seasonal data obtained from the prehistoric otoliths also match the seasonality of the modern fishery. Red cod are common between November and May from Banks Peninsula to Timaru. The implications of the results for pre historic seasonality in southern New Zealand are explored.