Reliability Assessment of Season-of-Capture Determination from Archaeological Otoliths
A technique involving microscopic examination of otolith growth zones has been commonly used by archaeologists along the coast of California to estimate season-of-capture of prehistoric fishes and to infer the season of site use. A test of otolith edge analysis techniques was performed on modern otoliths by estimating season-of-capture for otoliths with known dates of capture. Successful identification of season-of-capture was low, even in a best case scenario with the age-validated spotted sand bass (Paralabrax maculatofasciatus), emphasizing the subjectivity of this kind of analysis and inherent variability of growth zone formation in otoliths. Alteration of the otolith matrix from environmental factors further complicates the determination for archaeological otoliths, but surfperches (family Embiotocidae) hold promise for future studies. This study has called into question the validity of protocols that have not utilized age validated otolith collections and begs caution when estimating season-of-capture from otoliths.