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|Evaluating Largemouth Bass Dorsal Spine Aging Error Across Six Florida Waterbodies
|Presenting Author Name
|Presenting Author Affiliation
|Florida Fish and Wildlife Conservation Commission
|Presenting Author Email
|Type of Presentation
Nonlethal aging is a desired method for many species of fish. The social value of Florida Bass Micropterus floridanus, Largemouth Bass Micropterus salmoides, and their intergrades makes them prime candidates. Release rates are between 80–90% and TrophyCatch allows bass anglers to submit their catches to a citizen-science database. These no-kill ideals and collaborative programs provide impetus for developing a nonlethal aging method to collect more data on bass population dynamics in Florida. Historically, dorsal spines have provided variable levels of aging accuracy, depending on latitude, methodology, experience level, among other factors. We compared ages from three readers derived from bass dorsal spine sections among six waterbodies with different growth rates (Stick Marsh Reservoir, Fellsmere Reservoir, Lake Griffin, Apalachicola River, Escambia River marsh, and L-67A Canal). Further evaluation of dorsal spine aging shows variable levels of accuracy and precision across waterbodies, readers, and use of reference sets. However, aging error was not significantly different across three readers and six waterbodies, besides between L-67A Canal and Stick Marsh Reservoir, according to one of our linear models. This insignificance is likely because agreement within a year was high across all waterbodies and readers (range = 71−93%). We incorporated use of a reference set into a new model; wherein we detected improved accuracy of dorsal spine ages in L-67A Canal and Fellsmere Reservoir. In some instances, dorsal spines would be useful for aging Largemouth Bass in a nonlethal fashion, particularly when incorporating a reference set during aging and if estimating fish age within a year is acceptable. This is promising especially for long or old fish which are rarely seen, and if encountered, not often sacrificed. Dorsal spines could provide managers viable and uncommon age information about trophy bass without the need to sacrifice this socially and biologically important segment of the population.