Using Otolith Analysis and Microchemistry to Estimate Growth and Identify Recruitment Sources of Ohio River Sauger
Sauger are a recreationally important species in the Ohio River basin and population assessment and monitoring is needed in order to provide accurate and useful management recommendations for management agencies to maintain the integrity of the fishery. The objectives of this study are to use stable isotope and trace element analyses of otoliths to identify principal recruitment sources and inter-river movement patterns of Ohio River sauger. Water data collected over several years indicate differences in chemistry between the Ohio River and its tributaries, allowing us to distinguish tributary versus river natal recruitment. Sauger were collected from the lower six pools of the Ohio River during November and December of 2014 and 2015, measured for length and weight, and their sagittal otoliths extracted for ageing and chemical analyses. Identification of the principal sources of sauger recruitment to the fishery in each of the lower Ohio River navigation pools will facilitate conservation of important natal habitats for this species and contribute to assessment of the most appropriate spatial scale for managing sauger stocks.