Environmental Factors and Stock Abundance Influence Year-Class Strength of Spotted Seatrout at Cedar Key, Florida

Abstract

Environmental pressures can influence recruitment of estuarine fishes by impacting growth and survival of juveniles as well as adult habitat use and behavior. Identifying potential drivers of year-class strength is an important tool for assessing stock health and implementing management decisions. The goal of this study was to determine how environmental factors and adult stock influence trends in recruitment of Spotted Seatrout Cynoscion nebulosus in Cedar Key, Florida. Juvenile indices of abundance were generated using sampling data from the Florida Fish and Wildlife Conservation Commission’s Fisheries-Independent Monitoring program. Young-of-the-year indices of abundance suggested that annual recruitment was variable in this system and declined throughout the majority of the 1996–2018 time series. Adult abundance and water temperature in the spawning season were the most significant variables in predicting Spotted Seatrout recruitment, and both had positive relationships with recruitment. Salinity and river discharge were not significant environmental variables in predicting year-class strength of Spotted Seatrout in this study. Our results indicated that recruitment was associated with interannual changes in water temperature and adult abundance, which could be used to explore how Spotted Seatrout recruitment dynamics could vary for stock assessments, for management decisions, and as a result of warming waters due to climate change.