R. Petrik et al., Recruitment of Atlantic croaker, Micropogonias undulatus: Do postsettlement processes disrupt or reinforce initial patterns of settlement?, FISH B, 97(4), 1999, pp. 954-961
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.