, Volume 25, Issue 5, pp 1033–1044 | Cite as

Impact of habitat edges on density and secondary production of seagrass-associated fauna



Species richness and abundance of seagrass-associated fauna are often positively correlated with seagrass biomass and structure complexity of the habitat. We found that while shoot density and plant biomass were greater in interior portions of turtle grass (Thalassia testudinum) beds than at edges, mean faunal density was significantly greater at edges than interior sites during 1994. This pattern was also observed in 1995, although differences were not significant. The four numerically dominant taxonomic groups showed varying degrees of elevated densitities at edges ofT. testudinum beds. Peracarids and polychaetes had significantly greater densities at edges oft. testudinum beds, while both decapods and gastropods showed dramatic temporal variability in density, with reversals in density between edge and interior occurring during the course of the study. This within-habitat variability in abundance may reflect both active accumulation of fauna at edges and settlement shadows for species with pelagic larvae. Active accumulation of highly mobile taxa seeking refuge in seagrass beds may explain the differences in density between edge and interior ofT. testudinum patches for peracarids in 1994 and in 1995. Active accumulation at edges may also explain differeces in density for some decapod taxa. Chauges in gastropod densities between habitats may reflect larval settlement patterns. Results showed a distinct settlement shadow for the gastropodCaecum nitidum whose densities (primarily second stage protoconch) increased by more than an order of magnitude in 1994. Settlement shadows and post-settlement processes may also explain density differences of polychaetes between the edge and interior ofT. testudinum patches. The differences in faunal densities between edge and interior habitat resulted in habitat specific differences in secondary production among the major taxonomic groups. On four of five dates in 1994 and in 1995, secondary production was greater at edge than interior locations. These unexpected results suggest that differences in faunal densities and secondary production between edges and interiors of seagrass patches represent a potentially vital link in seagrass trophic dynamics. If this elevated secondary production leads to increases in trophic transfer, then edges may serve as a significant trophic conduit to higher-level consumers in this system.


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Literature Cited

  1. Ackerman, J. D. andA. Okubo. 1993. Reduced mixing in a marine macrophyte canopy.Functional Ecology 7:305–309.CrossRefGoogle Scholar
  2. Almasi, M., C. Hoskin, J. Reed, andJ. Milo. 1987. Effects of natural and artificialThalassia on rates on sedimentation.Journal Sedimentary Petrology 57:901–906.Google Scholar
  3. Baltz, D. M., C. Rakocinski, andJ. W. Fleeger. 1993. Microhabitat use by marsh-edge fishes in a Louisiana estuary.Environmental Biology of Fishes 36:109–126.CrossRefGoogle Scholar
  4. Bell, J. andM. Westoby. 1986. Variationin seagrass height and density over a wide spatial scale: Effects on fish and decapods.Journal of Experimental Marine Biology and Ecology 104:275–295.CrossRefGoogle Scholar
  5. Bell, S. S., M. O. Hall, andB. D. Robbins. 1995. Toward a landscape approach in seagrass beds: Using macroalgal accumulation to address question of scale.Oecologia 104:163–168.CrossRefGoogle Scholar
  6. Bertness, M. D., S. D. Gaines, E. G. Stephens, andP. O. Yund. 1992. Components of recruitment in populations of the acorn barnacleSemibalanus balanoides (Linnaeus).Journal of Experimental Marine Biology and Ecology 156:199–215.CrossRefGoogle Scholar
  7. Bologna, P. A. X. 1998. The effects of seagrass habitat architecture on associated fauna. Ph.D. Dissertation, University of South Alabama, Mobile, Alabama.Google Scholar
  8. Bologna, P. A. X. andK. L. Heck. 1999. Macrofaunal associations with seagrass epiphytes: Relative importance of trophic and structural characteristics.Journal of Experimental Marine Biology and Ecology 242:21–39.CrossRefGoogle Scholar
  9. Bologna, P. A. X. andH. L. Heck. 2000. Impacts of seagrass habitat architecture on bivalve settlement.Estuaries 23:449–457.CrossRefGoogle Scholar
  10. Butman, C. A. 1987. Larval settlement of soft-sediment invertebrates: The spatial scales of pattern explained by active habitat selection and the emerging role of hydrodynamical processes.Oceanography Marine Biology Review 25:113–165.Google Scholar
  11. Didham, R., J. Ghazoul, N. Stork, andA. Davis. 1996. Insects in fragmented forests: A functional approach.Trends in Ecology and Evolution 11:255–260.CrossRefGoogle Scholar
  12. Donovan, T., P. Jones, E. Annand, andF. Thompson. 1997. Variation in local-scale edge effects: Mechanisms and landscape context.Ecology 78:2064–2075.Google Scholar
  13. Eckman, J. E. 1990. A model of passive settlement by planktonic larvae onto bottoms of differing roughness.Limnology and Oceanography 35:887–901.Google Scholar
  14. Edgar, G. 1990a. The use of the size structure of benthic macrofaunal communities to estimate faunal biomass and secondary production.Journal of Experimental Marine Biology and Ecology 137:195–214.CrossRefGoogle Scholar
  15. Edgar, G. 1990b. Population regulation, population dynamics and competition amongst mobile epifauna associated with seagrass.Journal of Experimental Marine Biology and Ecology 144: 205–234.CrossRefGoogle Scholar
  16. Edgar, G. J. andC. Shaw. 1995. The production and trophic ecology of shallow-water fish assemblages in southern Australia. I. Species richness, size-structure and production of fishes in Western Port, Victoria,Journal of Experimental Marine Biology and Ecology 194:53–81.CrossRefGoogle Scholar
  17. Emerson, C. W. andJ. Grant. 1991. The control of soft-shell clam (Mya arenaria) recruitment on intertidal sandflats by bedload sediment transport.Limnology and Oceanography 36: 1288–1300.Google Scholar
  18. Fonseca, M. S. andJ. S. Fisher. 1986. A comparison of canopy friction and sediment movement between four species of seagrass with reference to their ecology and restoration.Marine Ecology Progress Series 29:15–22.CrossRefGoogle Scholar
  19. Fonseca, M. S., J. C. Zeiman, G. W. Thayer, andJ. S. Fisher. 1982. Influence of the seagrass,Zostera narina, on current flow.Estuarine and Coastal Shelf Science 15:351–364.CrossRefGoogle Scholar
  20. Forman, R. andM. Gordon. 1981. Patches and structural components for a landscape ecology.Bioscience 31:733–740.CrossRefGoogle Scholar
  21. Gambi, M. C., A. R. M. Nowell. andP. A. Jumars. 1990. Flume observations on flow dynamics inZostera marina (eelgrass) beds.Marine Ecology Progress Series 61:159–169.CrossRefGoogle Scholar
  22. Heck, K. L., K. W. Able, C. T. Roman, andM. Fahay. 1995. Composition, abundance, biomass, and production of macrofauna in a New England estuary: Comparison among eelgrass meadows and other nursery habitats.Estuaries 18:379–389.CrossRefGoogle Scholar
  23. Heck, K. L. andL. B. Crowder. 1991. Habitat structure and predator-prye interactions, p. 281–299.In S. Bell, E. McCoy, and H. Mushinsky (eds.), Habitat Complexity: The Physical Arrangement of Objects in Space. Chapman and Hall, New York.Google Scholar
  24. Heck, K. L. andR. J. Orth. 1980. Seagrass habitats: The roles of habitat complexity, competition and predation in structuring associated fish and macroinvertebrate assemblages, p. 449–464.In V. S. Kennedy (ed.), Estuarine Perspectives. Academic Press, New York.Google Scholar
  25. Holling, C. S. 1992. Cross-scale morphology, geometry, and dynamics of ecosystems.Ecological Monographs 62:447–502.CrossRefGoogle Scholar
  26. Holt, R.D., G. R. Robinson, andM. S. Gaines. 1995. Vegetation dynamics in an experimentally fragmented landscape.Ecology 76:1610–1624.CrossRefGoogle Scholar
  27. Homziak, J., M. Fonseca, andW. Kenworthy. 1982. Macrobenthic community structure in a transplanted eelgrass (Zostera marina) meadow.Marine Ecology Progress Series 9:211–221.CrossRefGoogle Scholar
  28. Howard, R. 1985. Measurements of short-term turnover of epifauna within seagrass beds using an in situ staining method.Marine Ecology Progress Series 22:163–168.CrossRefGoogle Scholar
  29. Howard, R. 1987. Diel variation in the abundance of epifauna associated with seagrasses of the Indian River, Florida, USA.Marine Biology 96:137–142.CrossRefGoogle Scholar
  30. Irlandi, E. A. 1994. Large- and small-scale effects of habitat structure on rates of predation: How percent coverage of seagrass affects rates of predation and siphon nipping on an infaunal bivalve.Oecologia 98:176–183.CrossRefGoogle Scholar
  31. Iverson, R. L. andH.F. Bittaker. 1986. Seagrass distribution in the eastern Gulf of Mexico.Esttuarine, Coastal and Shelf Science 22:577–602.CrossRefGoogle Scholar
  32. Jonsson, P., C. Andre, andM. Lindegarth. 1991. Swimming behavior of marine bivalve larvae in a flume boundary-layer flow: Evidence for near-bottom confinement.Marine Ecology Progress Series 79:67–76.CrossRefGoogle Scholar
  33. Kneib, R. T. andS. L. Wagner. 1994. Nekton use of vegetated marsh habitats at different stages of tidal inundation.Marine Ecology Progress Series 106:227–238.CrossRefGoogle Scholar
  34. Koehl, M. 1986. Form and function of macroalgae in moving water, p. 291–314.In T. J. Givinish (ed.), On the Economy of Plant Form and Function. Cambridge University Press, Cambridge, U.K.Google Scholar
  35. Komatsu, T. andH. Kawai. 1992. Measurements of time-averaged intensity of water motion with plaster balls.Journal of Oceanography 48:353–365.CrossRefGoogle Scholar
  36. Kruess, A. andT. Tscharntke. 1994. Habitat fragmentation, species loss, and biological control.Science 264:1581–1584.CrossRefGoogle Scholar
  37. Larkum, A. W. andC. den Hartog. 1989. Evolution and biogeography of seagrasses, p. 112–156.In A. W. D. Larkum, A. J. McComb, and S. A. Shepherd (eds.), Biology of Seagrasses: A Treatise on the Biology of Seagrasses with Special Reference to the Australia Region. Elsevier Science Publishers, Amsterdam, The Netherlands.Google Scholar
  38. Lewis, F. G. 1984. The distribution of macrobenthic crustaceans associated withThalassia, Halodule, and bare sand substrata.Marine Ecology Progress Series 19:101–113.CrossRefGoogle Scholar
  39. Marba, N. andC. Duarte. 1995. Coupling of seagrass (Cymodocea nodosa) patch dynamics to subaqueous dune migration.Journal of Ecology 83:381–389.CrossRefGoogle Scholar
  40. Minchinton, T. E. 1997. Life of the edge: Conspecific attraction and recruitment of populations to disturbed habitats.Oecologia 111:45–52.CrossRefGoogle Scholar
  41. Minello, T. J., R. J. Zimmerman, andR. Medina. 1994. The importance of edge for natant macrofauna in a created salt marsh.Wetlands 14:184–198.CrossRefGoogle Scholar
  42. Nilsson, S. G. 1986. Are bird communities in small biotope patches random samples from communities in large patches?Biological Conservation 38:179–204.CrossRefGoogle Scholar
  43. Orth, R. J. 1977. The importance of sediment stability in seagrass communities, p. 281–300.In B. C. Coull (ed.), Ecology of Marine Benthos. University of South Carolina Press, Columbia, South Carolina.Google Scholar
  44. Orth, R. J. 1992. A perspective on plant-animal interactions in seagrasses: Physical and biological determinants influencing plant and animal abundance, p. 147–164.In D. John, S. Hawkins, and J. Price (eds.), Plant-Animal Interactions in the Marine Benthos, Special Volume 46. Systematics Association, Clarendon Press, Oxford, U.K.Google Scholar
  45. Orth, R. J., K. L. Heck, andJ. van Montfrans. 1984. Faunal communities in seagrass beds: A review of the influence of plant structure and prey characteristics of predator-prey relationships.Estuaries 7:339–350.CrossRefGoogle Scholar
  46. Orth, R. J. andJ. van Montfrans. 1987. Utilization of a seagrass meadow and tidal march creek by blue crabsCallinectes sapidus. I. Seasonal and annual variations in abundance with emphasis on post-settlement juveniles.Marine Ecology Progress Series 41:283–294.CrossRefGoogle Scholar
  47. Pineda, J. andH. Caswell. 1997. Dependence of settlement rate on suitable substrate area.Marine Biology 129:541–548.CrossRefGoogle Scholar
  48. Robbins, B. D. andS. S. Bell. 1994. Seagrass landscapes: A terrestrial approach to the marine subtidal environment.Trends in Ecology and Evolution 9:301–304.CrossRefGoogle Scholar
  49. Robertson, A. I. 1979. The relationship between annual production ratio and life spans for marine macrobenthos.Oecologia 38:193–202.CrossRefGoogle Scholar
  50. Savastano, K. J., K. H. Faller, andR. L. Iverson. 1984. Estimating vegetation coverage in St. Joseph Bay, Florida, with an airborne multispectral scanner.Photogrammetric Engineering and Remote Sensing 50:1159–1170.Google Scholar
  51. Sheridan, P. 1997. Benthos of adjacent mangrove, seagrass and non-vegetated habitats in Rookery Bay, Florida, USA.Estuarine, Coastal, and Shelf Science 44:455–469.CrossRefGoogle Scholar
  52. Snelgrove, P. 1994. Hydrodynamic enhancement of invertebrate larval settlement in microdepositional environments: Colonization tray experiments in a muddy habitat.Journal of Experimental Marine Biology and Ecology 176:149–166.CrossRefGoogle Scholar
  53. Sogard, S. andK. Able. 1994. Diel variation in immigration of fishes and decapod crustaceans to artificial seagrass habitats.Estuaries 17:622–630.CrossRefGoogle Scholar
  54. Sokol, R. R. andF. J. Rohlf. 1981. Biometry. W. H. Freeman and Company, New York.Google Scholar
  55. Sousa, W. P. 1979. Disturbance in marine intertidal boulder fields: The non-equilibrium maintenance of species diversity.Ecology 60:1225–1239.CrossRefGoogle Scholar
  56. Stoner, A. W. 1982. The influence of benthic macrophytes on the foraging behavior of pinfish,Lagodon rhomboides (Linnaeus).Journal of Experimental Marine Biology and Ecology 58:271–284.CrossRefGoogle Scholar
  57. Stoner, A. W. andF. Lewis. 1985. The influence of quantitative and qualitative aspects of habitat complexity in tropical seagrass meadows.Journal of Experimental Marine Biology and Ecology 94:19–40.CrossRefGoogle Scholar
  58. Summerson, C. H. andC. H. Peterson. 1984. Role of predation in organizing benthic communities of a temperate-zone seagrass bed.Marine Ecology Progress Series 15:63–77.CrossRefGoogle Scholar
  59. Thayer, G. W., W. Kenworthy, and M. Fonseca. 1984. The Ecology of Eelgrass Meadows of the Atlantic Coast: A Community Profile. U.S. Fish and Wildlife Service Biology Series Progress FWS/OBS-84/02, Washington, D.C.Google Scholar
  60. Valentine, J. F. andK. L. Heck, Jr. 1993. Mussels in seagrass meadows: Their influence on macroinvertebrate abunance and secondary production in the Northern Gulf of Mexico.Marine Ecology Progress Series 96:63–74.CrossRefGoogle Scholar
  61. Virnstein, R. andM. Curran. 1986. Colonization of artificial seagrass versus time and distance from source.Marine Ecology Progress Series 29:279–288.CrossRefGoogle Scholar
  62. Virnstein, R., P. S. Mikkelsin, K. D. Cairns, andM. A. Capone. 1983. Seagrass beds versus sand bottoms: The trophic importance of their associated invertebrates.Florida Scientist 46:363–381.Google Scholar
  63. Virnstein, R., W. G. Nelson, F. G. Lewis, andR. K. Howard. 1984. Latitudinal patterns in seagrass epifauna: Do patterns exist, and can they be explained?.Estuaries 7:310–330.CrossRefGoogle Scholar
  64. White, P. S. 1987. Natural disturbance, patch dynamics, and landscape pattern in natural areas.Natural Areas Journal 7:14–22.Google Scholar
  65. Worthington, D., D. Ferrell, S. McNeill, andJ. Bell. 1992. Effect of the shoot density of seagrass on fish and decapods: Are correlations evident over larger spatial scales?.Marine Biology 112:139–146.CrossRefGoogle Scholar

Copyright information

© Estuarine Research Federation 2002

Authors and Affiliations

  1. 1.Department of Marine Sciences, Dauphin Island Sea LabUniversity of South AlabamaDauphin Island
  2. 2.Department of Biological and Allied Health SciencesFairleigh Dickinson UniversityMadison

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