Abstract
Two conflicting models for the organisation of assemblages of fish and decapods associated with seagrass over large spatial scales, make contradictory predictions about the relationship between density of seagrass shoots and abundance, or diversity, of animals. We tested the predictions of both models by sampling small lish and decapods associated with two species of seagrass (Zostera capricorni Aschers and Posidonia australis Hook) at up to 16 sites within several estuaries in New South Wales, Australia, for 1.5 yr (December 1988 to March 1990). Variation in density of Z. capricorni shoots explained very little of the variation in abundance of animals. However, abundance of one species, the grass shirmp Macrobrachium intermedium, was more closely related to the density of shoots during non-recruitment seasons, suggesting that predation or emigration of individuals after settlement was greater in sparse beds. The effect of variation in density of P. australis shoots was confounded with consistent distribution patterns of most fish and decapod species. As a result, data from P. australis did not provide good tests of the hypotheses. We conclude that density of seagrass shoots explained very little of the large-scale variation in abundance of associated fish and decapods. The data do, however, support the inodel which predicts that the abundance of animals among separate seagrass beds will follow the supply of new individuals to them.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Literature cited
Adams, S. M. (1976). The ecology of eelgrass, Zostera marina (L.), fish communities. I. Structural analysis. J. exp. mar. Biol. Ecol. 22: 269–291
Andrew, N. L., Underwood, A. J. (1989). Patterns of abundance of the sea urchin Centrostephanus rodgersii (Agassiz) on the central coast of New South Wales, Australia. J. exp. mar. Biol. Ecol. 131: 61–80
Bell, J. D., Steffe, A. S., Westoby, M. (1988). Location of seagrass beds in estuaries: effects on associated fish and decapods. J. exp. mar. Biol. Ecol. 122: 127–146
Bell, J. D., Westoby, M. (1986a). Importance of local changes in leaf height and density to fish and decapods associated with seagrasses. J. exp. mar. Biol. Ecol. 104: 249–274
Bell, J. D., Westoby, M. (1986b). Abundance of macrofauna in dense seagrass is due to habitat preference, not predation. Oecologia 68: 205–209
Bell, J. D., Westoby, M. (1986c). Variation in seagrass height and density over a wide spatial scale: effects on fish and decapods. J. exp. mar. Biol. Ecol. 104: 275–295
Bell, J. D., Westoby, M., Steffe, A. S. (1987). Fish larvae settling in seagrass: do they discriminate between beds of different leaf density? J. exp. mar. Biol. Ecol. 111: 133–144
Butler, A. J. (1986). Recruitment of sessile invertebrates at five sites in Gulf St. Vincent, South Australia. J. exp. mar. Biol. Ecol. 97: 13–36
Choat, J. H., Ayling, A. M. (1987). The relationship between habitat structure and fish faunas on New Zealand reefs. J. exp. mar. Biol. Ecol. 110: 257–284
Cohen, J. (1988). Statistical power analysis for the behavioural sciences. Lawrence Erlbaum Associates, New Jersey
Fairweather, P. G. (1988). Predation creates haloes of bare space among prey on rocky seashores in New South Wales. Aust. J. Ecol. 13: 401–409
Ferrell, D. J., Bell, J. D. (1991). Differences among assemblages of fish associated with Zostera capricorni and bare sand over a large spatial scale. Mar. Ecol. Prog. Ser. 72: 15–24
Gore, R. H., Gallaher, E. E., Scotto, L. E., Wilson, K. A. (1981). Studies on decapod crustacea from the Indian River region of Florida. XI. Community composition, structure, biomass and species-areal relationships of seagrass and drift algae-associated macrocrustaceans. Estuar., cstl Shelf Sci. 12: 485–508
Gotceitas, V., Colgan, P. (1989). Predator foraging success and habitat complexity: quantitative test of the threshold hypothesis. Oecologia 80: 158–166
Gray, C. A. (1991). Temporal variability in the demography of the palaemonid prawn Marcrobrachium intermedium in two seagrasses. Mar. Ecol. Prog. Ser. 75: 227–238
Heck, K. L. Jr., Orth, R. J. (1980). Seagrass habitats: the roles of habitat complexity, competition and predation in structuring associated fish and motile macroinvertebrate assemblages. In: Kennedy, V. S. (ed.) Estuarine perspectives. Academic Press, New York, p. 449–464
Heck, K. L., Wetstone, G. S. (1977). Habitat complexity and invertebrate species richness and abundance in tropical seagrass meadows. J. Biogeogr. 4: 135–142
Jones, G. P. (1984). Population ecology of the temperate reef fish Pseudolabrus celidotus Bloch and Schneider (Pisces: Labridae). I. Factors influencing recruitment. J. exp. mar. Biol. Ecol. 75: 257–276
Jones, G. P. (1990). The importance of recruitment to the dynamics of a coral reef fish population. Ecology 71: 1691–1698
Leber, K. M. (1985). The influence of predatory decapods, refuge, and microhabitat selection on seagrass communities. Ecology 66: 1951–1964
Luckhurst, B. E., Luckhurst, K. (1978). Analysis of the influence of substrate variables on coral reef fish communities. Mar. Biol. 49: 317–323
McNeill, S. E., Bell, J. D. (1991). Optimising the design and use of a beam trawl for sampling macro-fauna of Posidonia seagrass. (in preparation)
Nelson, W. G. (1979). Experimental studies of selective predation on amphipods: consequences for amphipod distribution and abundance. J. exp. mar. Biol. Ecol. 38: 225–245
Nelson, W. G., Bonsdorff, E. (1990). Fish predation and habitat complexity: are complexity thresholds real? J. exp. mar. Biol. Ecol. 141: 183–194
Orth, R. J., Heck, K. L. Jr. (1980). Structural components of eelgrass (Zostera marina) meadows in the lower Chesapeake Bayfishes. Estuaries 3: 278–288
Orth, R. J., Heck, K. L. Jr., van Montfrans, J. V. (1984). Faunal communities in seagrass beds: a review of the influence of plant structure and prey characteristics on predator-prey relationships. Estuaries 7: 339–350
Sale, P. F., Doherty, P. J., Eckert, G. J., Douglas, W. A., Ferrell, D. J. (1984). Large scale spatial and temporal variation in recruitment to fish populations on coral reefs. Oecologia 64: 191–198
Sogard, S. M. (1989). Colonization of artificial seagrass by fishes and decapod crustaceans: importance of proximity to natural eelgrass. J. exp. mar. Biol. Ecol. 133: 15–37
Underwood, A. J. (1981). Techniques of analysis of variance in experimental marine biology and ecology. Oceanogr. mar. Biol. A. Rev. 19: 513–605
Underwood, A. J., Barrett, G. (1990). Experiments on the influence of oysters on the distribution, abundance and sizes of the gastropod Bembicium auratum in a mangrove swamp in New South Wales, Australia. J. exp. mar. Biol. Ecol. 137: 25–45
Underwood, A. J., Fairweather, P. G. (1989). Supply-side ecology and benthic marine assemblages. Trends Ecol. Evol. 4: 16–20
Watanabe, J. M. (1984). The influence of recruitment, competition, and benthic predation on spatial distributions of three species of kelp forest gastropods (Trochidae: Tegula). Ecology 65: 920–936
Williams, A. H., Coen, L. D., Stoelting, M. S. (1990). Seasonal abundance, distribution, and habitat selection of juvenile Callinectes sapidus (Rathbun) in the northern Gulf of Mexico. J. exp. mar. Biol. Ecol. 137: 165–183
Worthington, D. G., Westoby, M., Bell, J. D. (1991). Fish larvae settling in seagrass: effects of leaf density and an epiphytic alga. Aust. J. Ecol. 16: 289–293
Author information
Authors and Affiliations
Additional information
Communicated by G.F. Humphrey, Sydney
Rights and permissions
About this article
Cite this article
Worthington, D.G., Ferrell, D.J., McNeill, S.E. et al. Effects of the shoot density of seagrass on fish and decapods: are correlation evident over larger spatial scales?. Marine Biology 112, 139–146 (1992). https://doi.org/10.1007/BF00349737
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00349737