ST0NER: SEAGRASS RHTHVOPAUNA 



movement of fishes and invertebrates between 

 seagrass beds and coral reefs is common (Randall 

 1965; Ogden and Buckman 1973; Ogdenand Zieman 

 1977). In Apalachee Bay, lack of diurnal change in 

 species composition probably relates to the enor- 

 mous size of the meadow (continuous for hundreds of 

 square kilometers) and the fact that no alternative 

 habitats are in close proximity except for occasional 

 patches of bare sand or mud. Despite the smaller, 

 band or patchlike nature of seagrass beds in Indian 

 River lagoon, the ichthyofauna found there were also 

 full-time residents. An examination of the food habits 

 of temperate seagrass-associated fishes (Carr and 

 Adams 1973; Livingston 1982) indicates that most 

 consume prey items normally found among the mac- 

 rophytes. Also, most appear to be visual predators 

 which rest near bottom at night (pers. obs.), taking 

 advantage of the shelter provided by the seagrass 

 blades. It would appear, therefore, that fishes in the 

 temperate regions examined do not move to and from 

 seagrass beds, except for a few species of nocturnal 

 predators which move into the beds at night. In- 

 creased catches at night are most likely related to in- 

 activity of many species and the resultant elevation in 

 capture efficiency. 



Because trawl efficiency probably decreases with 

 seagrass biomass, fish populations in Apalachee Bay 

 would have been underestimated most severely at 

 the most heavily vegetated station E-12 and least at 

 station F-ll; therefore, the relationship between 

 seagrass biomass and fish abundance is probably 

 even more pronounced than that demonstrated. In 

 Indian River lagoon, seagrass biomass was similar at 

 the Syringodium and Ha/odule beds, but the high 

 density of Halodule blades might serve to reduce 

 trawl efficiency as would high biomass at the 

 Thalassia bed. Estimates of fish abundance at the 

 Halodule and Thalassia beds, therefore, may be low, 

 in relative terms. Because the limited collections 

 made at night yielded much higher numbers of fishes 

 and more clearly separated the stations in Indian 

 River lagoon, future trawl studies should be conduct- 

 ed at night despite the inherent difficulties. New sur- 

 veys in other areas would be particularly valuable in 

 establishing the universality of relationships observed 

 between fishes and seagrass biomass and seagrass 

 species. 



ACKNOWLEDGMENTS 



Fish collections in Apalachee Bay were supported 

 in part by grant R-8052880 1 from the U. S. Environ- 

 mental Protection Agency to Robert J. Livingston. 

 Indian River collections were supported by a 



postdoctoral fellowship in benthic ecology to the 

 author from the Harbor Branch Institution. I thank R. 

 J. Livingston (Florida State University), R. W. Vim- 

 stein, and R. G. Gilmore (Harbor Branch Foundation) 

 for their assistance in the planning and design of the 

 collections reported here. Numerous graduate 

 students and support staff including P. A. Hastings 

 and M. A. Clark were of valuable assistance in the 

 field work and fish identifications. R. G. Gilmore, F. 

 G. Lewis, B. F. Mahoney, R. W. Virnstein, and M. P. 

 Weinstein provided critical reviews of the 

 manuscript. 



LITERATURE CITED 



Adams, S. M. 



1976. The ecology ofeelgrass, Zostera marina (L.), fish com- 

 munities. I. Structural analysis. J. Exp. Mar. Biol. EcoL 

 22:269-291. 



Brady, K. D. 



1981. Seasonal and spatial distribution of ichthyoplankton 

 in seagrass beds of Apalachee Bay. M.S. Thesis, Florida 

 State Univ., Tallahassee, 169 p. 

 Briggs, P. T, and J. S. O'Connor. 



1971. Comparison of shore-zone fishes over naturally- 

 vegetated and sand-filled bottoms in Great South 

 Bay. N.Y. Fish Game J. 18:15-41. 

 Carr, W. E. S., and C. A. Adams. 



1973. Food habits of juvenile marine fishes occupying 

 seagrass beds in the estuarine zone near Crystal River, 

 Florida. Trans. Am. Fish. Soc. 102:51 1-540. 



Coen, L. D.. K. L. Heck, Jr., and L. G. Abele. 



1981. Experiments on competition and predation among 

 shrimps of seagrass meadows. Ecology 62:1484-1493. 



Greening, H. S., and R. J. Livingston. 



1982. Diel variation in the structure of seagrass-associated 

 epibenthic macroinvertebrate communities. Mar. Ecol. 

 Prog. Ser. 7:147-156. 



Heck, K. L., Jr., and R. J. Orth. 



1980. Seagrass habitats: the roles of habitat complexity, 

 competition and predation in structuring associated fish 

 and motile invertebrate assemblages. In V. S. Kennedy 

 (editor), Estuarine perspectives, p. 449-464. Acad. 

 Press, N.Y. 



Heck, K. L., Jr., and G. S. Wetstone. 



1977. Habitat complexity and invertebrate species richness 

 and abundance in tropical seagrass meadows. J. 

 Biogeogr. 4:135-142. 



Hoese. H. D., and R. S. Jones. 



1963. Seasonality of larger animals in a Texas turtle grass 

 community. Publ. Inst. Mar. Sci. Univ. Tex. 9:37-47. 

 KlKUCHI, T 



1966. An ecological study on animal communities of the Zn.s- 

 tera marina belt in Tomioka Bay, Amakusa. Kyushu 

 Univ. Publ., Amakusa Mar. Biol. Lab. 1:1-106. 



1974. Japanese contributions on consumer ecology in 

 eelgrass (Zostera marina L.) beds, with special reference 

 to trophic relationships and resources in inshore 

 fisheries. Aquaculture 4:145-160. 



Kikuchi, T, and J. M. Peres. 



1977. Consumer ecology of seagrass beds. In C. P. McRoy 

 and C. Helfferich (editors), Seagrass ecosystems: a scien- 

 tific perspective, p. 147-193. Marcel Dekker, N.Y. 



845 



