Comparison Of Techniques Used To Age Yellow Perch In Southern Lake Michigan
Cassandra J. May, Ball State University, Muncie, IN 47306; (765) 214-0091; cjnoble@bsu.edu
Thomas E. Lauer, Aquatic Biology and Fisheries Center, Department of Biology, Ball State University, Muncie, IN 47306
Previous studies have been conducted comparing the precision of yellow perch (Perca flavescens) scales to otoliths and scales to opercles. In each study, scales have proven to be less precise. Therefore, the goal of this study was to compare opercles to otoliths while establishing the best methodology to use for ageing otoliths. Opercles and otoliths were collected from 224 yellow perch in the summer of 2003 from three sites located in Southern Lake Michigan. Otoliths and opercles were both read as whole structures and aged twice by two independent readers. Opercles were the most precise ageing structure based on percent agreement (46%) and coefficient of variation (12.6%). Otoliths yielded less precise results with 28% agreement and a 25.4% coefficient of variation. Further investigation into the ageing of yellow perch improves the efficiency and precision of the ageing process. As a result, better fisheries management practices can be utilized.