Black Bass Diversity: Multidisciplinary Science for Conservation

Stock Assessment of Shoal Bass in the Chipola River, Florida

Katie L. Woodside, Christopher J. Paxton, and Nicole C. Kierl

doi: https://doi.org/10.47886/9781934874400.ch14

Abstract.—We conducted a stock assessment of Shoal Bass Micropterus cataractae in the upper Chipola River in Jackson and Calhoun counties, Florida from 2007 to 2012 to aid in the species’ conservation. Shoal Bass are currently listed as a species of special concern by the American Fisheries Society and are a recreational sport fish species in Florida. Previous Shoal Bass research in Florida was limited in terms of quantified habitat use or population abundance. Although one of the potential threats to Shoal Bass in the Chipola River has been described as sedimentation, little information existed regarding abundance, growth, mortality, or fishing effort. Shoal Bass and sympatric Largemouth Bass M. salmoides were collected by electrofishing from three study reaches. Modified Schnabel population estimates from mark– recaptured fish were used to describe abundance in 2009, 2010, and 2011. A roving creel survey was conducted in 2010 and 2011 to provide effort, total catch, catch per unit effort (fish caught per angler-hour), and harvest estimates. Mean total length at age was described by von Bertalanffy growth curves for Shoal Bass collected in 2008 and 2010, and growth differed between years. Total annual mortality (A) for Shoal Bass averaged 57% and was greater than total annual mortality for Largemouth Bass (A = 32%, P = 0.009) at this system. Missing or underrepresented year-classes from the 2008 and 2010 Shoal Bass age samples suggested highly variable recruitment. Strong Shoal Bass year-classes were associated with low median flows and low flow variation in spring and summer. An abundant population of Shoal Bass exists in the Chipola River, and the fishery received low angling harvest and directed effort. However, Shoal Bass remain potentially threatened by sedimentation, variable hydrologic events, and its confined range and habitat requirements.