| ENERGETICS OF JUVENILE GRAY SNAPPER: EVALUATION OF ABIOTIC AND BIOTIC PROPERTIES OF NURSERY AREAS ACROSS A LATITUDINAL GRADIENT |
| WUENSCHEL, M. J., Rutgers University Marine Field Station, 800 c/o 132 Great Bay BLVD, Tuckerton, NJ, USA, 08087, wuensche@marine.rutgers.edu, Hare, J. A. NOAA NMFS NEFSC, Narragansett Lab, Narragansett, RI, USA 02882 |
| A bioenergetic model is presented for juvenile gray snapper (Lutjanus griseus) to evaluate the importance of abiotic and biotic properties of nursery habitats across a latitudinal gradient. The model was applied to juveniles collected from five estuaries (4 in Florida and one in North Carolina) in 2000 and 2001. Site-specific temperature and salinity records were combined with age and growth information from otolith analysis. Individual growth trajectories were fit to obtain the observed size at capture by iteratively adjusting the proportion of maximum consumption (PCMAX); PCMAX incorporates biotic components such as food availability and can serve as a proxy for habitat quality. Although growth rates were generally faster at southern sites, however temperature only explained ~50% of the variability in juvenile growth rate. Analyses indicate that fish at northern sites attained high growth rates at suboptimal temperatures by feeding near the maximum level, while individuals from southern sites with more optimal temperatures did not feed at near maximum levels. Therefore, growth in nursery habitats at northern sites may be largely limited by temperature, while farther south growth may be limited by other aspects of habitat quality such as food availability.
|
| back |
|
