A Method for Estimating Year Class Strength from Abundance Data with Application to the Fishery of Green Bay, Lake Michigan

Non-stationary recruitment dynamics of rainbow smelt: The influence of environmental variables and variation in size structure and length-at-maturation

“…This inconsistent relationship between spawning stock biomass and α, coupled with the lack of a significant density dependent term in the KF-RW model, does not fit with previous research conclusions regarding rainbow smelt recruitment. Specifically, compensatory density dependence has been commonly observed in other populations of Great Lakes rainbow smelt, including cannibalism, poor egg survival at high densities, and intraspecific competition (Henderson and Nepszy, 1989;He and LaBar, 1994;McKenzie, 1964;Walter and Hoagman, 1975). Moreover, recent increases in α appear incongruous with the concomitant decreases in size structure and length at maturation we observed because smaller, younger smelt likely produce fewer eggs (Dunstall, 1980) and in many fish smaller mothers also produce eggs of poorer quality through maternal effects on egg size or larval characteristics (Berkeley et al, 2004;Olin et al, 2012).…”