Warmer springs may lead to more frequent spawning in lake sturgeon

Environmental variation and life history influence reproductive behavior in fishes. Many iteroparous fishes, like lake sturgeon, may transition between spawning and non-spawning states among years in response to recent spawning history, sex, and environmental variation leading to variation in interannual spawning intervals, with strong implications for conservation and management. We combined three capture–mark–recapture datasets to jointly estimate interannual spawning state transitions in lake sturgeon of the lower Niagara River between 2011 and 2020, where temperature drives strong interannual environmental variation. Our Bayesian multi-state capture–mark–recapture model suggested interannual spawning state transitions were best explained by sex-specific responses to water temperatures during the previous spring. With higher spring temperatures, males were less likely to delay spawning, while females were more likely to re-engage in spawning after delaying. Our model thus suggests that both sexes shorten intervals between spawning years in response to warming. Conservation and management of lake sturgeon in the lower Niagara River should account for the link between spawning behavior and environmental temperature, underscoring the need to address similar questions in other long-lived imperiled taxa.