Defining the fundamental physiological niche of young estuarine fishes and itsrelationship to understanding distribution,vital metrics,and optimal nurseryconditions

Because estuarine nekton are integrators of the environment abiotic and biotic factors can influence or constrain the relative value of estuarine nursery zones. Recent laboratory experiments on young spot, Leiostomus xanthurus, indicate that both water temperature and salinity significantly affect somatic growth. These experimental data contrast with previous work on young Atlantic croaker,Micropogonias undulatus, white trout,Cynoscion arenarius, and mullet,Mugil sp. Together these results suggest that quantifying vital metrics of nekton, such as survival and growth, along realistic environmental gradients through critical laboratory experiments, allows a more accurate definition of constraints on habitat use. Our studies of factors influencing recruitment success in both winter- and spring/summer-spawning fishes illustrate seasonal as well as intrafamilial differences in growth. Effective management of coastal ecosystems must take into account both variability in abiotic conditions and the nested habitat component, both of which can be modified by coastal development, which could lead to reduced productivity and sustainability of these estuarine landscapes.