Recruitment of Atlantic croaker, Micropogonias undulatus: Do postsettlement processes disrupt or reinforce initial patterns of settlement?

Understanding the relative importance of pre- and postsettlement processes is critical to understanding the population dynamics of marine fishes. Our goals in this study were 1) to examine habitat preference and habitat use o f newly settled Atlantic croaker, Micropogonias undulatus, and 2) to determ ine if postsettlement growth or predation Varied with habitat type. Field s urveys showed no difference in croaker abundance among three estuarine habi tats: marsh edge, seagrass, and sand. Behavioral experiments in laboratory mesocosms suggested that the pattern of similar use of habitats in the fiel d results from a lack of preference among habitats. In a field experiment, croaker recruitment was greater to artificial seagrass than to sand habitat s, but there was no difference in fish density in habitats with or without food supplementation. Moreover, growth rates were similar in both sand and artificial seagrass habitats and in habitats with or without food supplemen tation. In a second experiment, we were unable to detect a difference in th e density of newly settled croaker between sand and artificial seagrass hab itats, or between habitats with predator access limited by cages and cage c ontrols. Our results demonstrate that newly settled croaker use different e stuarine habitats similarly, and there does not appear to be a fitness cons equence of using many habitats. We suggest that for habitat generalists, su ch as the Atlantic croaker, variability in larval supply will be a stronger predictor of population dynamics than will variability of habitat attribut es.