Age Estimate Precision of Bluegill and Redear Sunfish Using Broken and Whole Otoliths

Age estimate precision is essential for fisheries managers when evaluating age structure, growth, and mortality rates for fish populations; therefore, establishing the method with the greatest precision for a particular species is critical. We compared ages estimated from broken and whole otoliths of 693 bluegill (Lepomis macrochirus) and 432 redear sunfish (L. microlophus) from five small impoundments (6.5?101 ha) in Oklahoma. Bluegill ages ranged from 0 to 10, and redear sunfish ranged from 0 to 9. We observed high agreement and precision between readers for ages estimated using broken and whole otoliths for bluegill and redear sunfish (percent agreement=88%?100%; mean CV=0?5%; average percent error=0?3.5%). Although rare, when bias was observed, the ages of older fish (≥age 6) of both species were underestimated using whole otoliths compared to broken otoliths, and this was more noticeable when evaluating between-reader precision rather than final consensus ages. Agreement between final consensus ages was high for bluegill (95%?99%) and redear sunfish (98%?100%) across populations. Sunfish growth rates may be sufficient to prevent annuli from constricting on the otolith edge in southern U.S. waters, allowing the use of whole otoliths for age estimation. Small differences in aging precision were observed between species and among lakes, suggesting that aging precision should be evaluated on a case-by-case basis to ensure accurate population parameters are calculated using a particular aging method

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