Tuckey and Dehaven: Fish assemblages found in tidal creek and seagrass habitats in the Suwannee River estuary 



113 



tidal creeks and dominated samples collected during 

 January and February (Tables 2 and 5). Recruitment 

 of YOYL. rhomboides and C. arenarius also contributed 

 to the winter-spring species assemblage (Tables 4 and 

 5). The summer assemblage was influenced by recruit- 

 ment of YOY F. grandis and C. nebulosus, which had 

 significantly shorter standard lengths than they had 

 in the winter-spring assemblage. The recruitment of 

 S. ocellatus helped to characterize the fall assemblage. 

 Emigration of larger individuals could also account for 

 a decrease in mean length; however length-frequency 

 plots showed that larger individuals remained vulner- 

 able to the gear and that the reduction in mean length 

 was due to recruitment of YOY fishes. 



Discussion 



Fishes collected in seagrass habitats in this study were 

 similar to those found in other studies of seagrass hab- 

 itats; resident species were present year-round and 

 there were seasonal pulses of juveniles that used the 

 seagrass habitats as a nursery (Reid, 1954; Livingston, 

 1982; Weinstein and Brooks, 1983). The assemblages we 

 identified were the result of the staggered influx of YOY 

 fishes of different species to seagrass habitats through- 

 out the year. For example, YOY L. rhomboides and O. 

 chrysoptera recruited during winter and spring, whereas 

 other abundant species such as YOY B. chrysoura and 

 Eucinostomus spp. entered the nursery during summer 

 and fall. We found an increase in species abundance 

 and species richness during summer and fall similar 

 to that found by Reid (1954), who conducted his study 

 near Cedar Key. The same pattern was evident in other 

 estuarine systems (Cowan and Birdsong, 1985; Rooker 



et al., 1998), demonstrating that recruitment of many 

 juvenile fish species to seagrass habitats during summer 

 and fall allows the juveniles to use the protection pro- 

 vided by the growing seagrasses (Stoner, 1983) and to 

 use the food resources found within them (Carr and 

 Adams, 1973). 



Early-life-history stages of species with commercial 

 or recreational importance were found in each habi- 

 tat, but seagrass habitats contained a greater variety 

 of juveniles from offshore reef species than did tidal 

 creeks. Along the southeastern United States, juveniles 

 of many economically important species use a variety 

 of habitats in estuaries as nurseries, including man- 

 groves, oyster reefs, marshes, tidal creeks, and seagrass 

 habitats (Coleman et al., 1999, Coleman, et al., 2000). 

 In our study. YOY reef fish taxa, such as serranids, 

 lutjanids, and haemulids, were more abundant in sea- 

 grass habitats than they were in tidal-creek habitats, 

 except for gray snapper [Lutjanus griseus). Juveniles of 

 several reef species (C. striata, Mycteroperca microlepis, 

 Serraniculus pumilio, Serranus subligaris, and Lachno- 

 laimus maximus) were found only in seagrass habitats. 

 However, a complicating factor in our study was the 

 elimination of oyster habitats from our sampling design. 

 Oyster reefs are known to harbor juvenile C. striata 

 and M. microlepis (Coleman et al., 2000) and they may 

 have been under-estimated in our study because we 

 did not sample these habitats. Other economically im- 

 portant species, such as C. nebulosus, also recruited to 

 the seagrass habitats and are known to reside in them 

 much of their life (Reid, 1954; McMichael and Peters, 

 1989; Mason and Zengel, 1996). These economically im- 

 portant species use seagrass habitats in the Suwannee 

 River estuary as a nursery and eventually enter local 

 fisheries. Consequently, the maintenance of healthy 



