Abstract
Changes in seagrass food-web structure can shift the competitive balance between seagrass and algae, and may alter the flow of energy from lower trophic levels to commercially important fish and crustaceans. Yet, trophic relationships in many seagrass systems remain poorly resolved. We estimated the food web linkages among small predators, invertebrate mesograzers, and primary producers in a Chesapeake Bay eelgrass (Zostera marina) bed by analyzing gut contents and stable C and N isotope ratios. Though trophic levels were relatively distinct, predators varied in the proportion of mesograzers consumed relative to alternative prey, and some mesograzers consumed macrophytes or exhibited intra-guild predation in addition to feeding on periphyton and detritus. These findings corroborate conclusions from lab and mesocosm studies that the ecological impacts of mesograzers vary widely among species, and they emphasize the need for taxonomic resolution and ecological information within seagrass epifaunal communities.
References
Bobsien, I.C. 2006. The role of small fish species in eelgrass food webs of the Baltic Sea. Dissertation, Christian-Albrechts-Universität zu Kiel, Germany
Canuel, E.A., J.E. Cloern, D.B. Ringelberg, J.B. Guckert, and G.H. Rau. 1995. Molecular and isotopic tracers used to examine sources of organic matter and its incorporation into the food webs of San Francisco Bay. Limnology and Oceanography 40: 67–81.
Cardinale, B.J., D.S. Srivastava, J.E. Duffy, J.P. Wright, A.L. Downing, M. Sankaran, and C. Jouseau. 2006. Effects of biodiversity on the functioning of trophic groups and ecosystems. Nature 443: 989–992.
Cerco, C.F., and K. Moore. 2001. System-wide submerged aquatic vegetation model for Chesapeake Bay. Estuaries 24: 522–531.
Chanton, J.P., and F.G. Lewis. 1999. Plankton and dissolved inorganic carbon isotopic composition in a river-dominated estuary: Apalachicola Bay, Florida. Estuaries 22: 575–583.
Douglass, J.G., J.E. Duffy, A.C. Spivak, and J.P. Richardson. 2007. Nutrient versus consumer control of community structure in a Chesapeake Bay eelgrass habitat. Marine Ecology Progress Series 348: 71–83.
Douglass, J.G., J.E. Duffy, and J.E. Bruno. 2008. Herbivore and predator diversity interactively affect ecosystem properties in an experimental marine community. Ecology Letters 11: 598–608.
Douglass, J.G., K.E. France, J.P. Richardson, and J.E. Duffy. 2010. Seasonal and interannual change in a Chesapeake Bay eelgrass community: insights into biotic and abiotic control of community structure. Limnology and Oceanography 55: 1499–1520.
Duffy, J.E. 2002. Biodiversity and ecosystem function: the consumer connection. Oikos 99: 201–219.
Duffy, J.E., and M.E. Hay. 2000. Strong impacts of grazing amphipods on the organization of a benthic community. Ecological Monographs 70: 237–263.
Duffy, J.E., and A.M. Harvilicz. 2001. Species-specific impacts of grazing amphipods in an eelgrass bed community. Marine Ecology Progress Series 223: 201–211.
Duffy, J.E., J.P. Richardson, and K.E. France. 2005. Ecosystem consequences of diversity depend on food chain length in estuarine vegetation. Ecology Letters 8: 301–309.
Eriksson, B.S., L. Ljunggren, A. Sandström, G. Johansson, J. Mattila, A. Rubach, S. Råeberg, and M. Snickars. 2009. Declines in predatory fish promote bloom-forming macroalgae. Ecological Applications 19: 1975–1988.
Fry, B. 2006. Stable isotope ecology. New York: Springer.
Haahtela, I. 1984. A hypothesis of the decline of the bladder wrack (Fucus vesiculosus L.) in SW Finland in 1975–1981. Limnologica 15: 345–350.
Hines, A.H., A.M. Haddon, and L.A. Wiechert. 1990. Guild structure and foraging impact of blue crabs and epibenthic fish in a subestuary of Chesapeake Bay. Marine Ecology Progress Series 67: 105–126.
Hughes, A.R., K.J. Bando, L.F. Rodriguez, and S.L. Williams. 2004. Relative effects of grazers and nutrients on seagrasses: a meta-analysis approach. Marine Ecology Progress Series 282: 87–99.
Jaschinski, S., N. Aberle, S. Gohse-Reiman, H. Brendelberger, K.H. Wiltshire, and U. Sommer. 2009. Grazer-diversity effects in an eelgrass–epiphyte microphytobenthos system. Oecologia 159: 607–615.
Jernakoff, P., A. Brearly, and J. Nielsen. 1996. Factors affecting grazer–epiphyte interactions in temperate seagrass meadows. Oceanography and Marine Biology: An Annual Review 34: 109–162.
Kangas, P., H. Autio, G. Haellfors, H. Luther, A. Niemi, and H. Salemaa. 1982. A general model of the decline of Fucus vesiculosus at Tvaerminne, south coast of Finland in 1977–81. Acta Botanica Fennica 118: 1–27.
Kirkman, H. 1978. Growing Zostera capricorni Aschers. in tanks. Aquatic Botany 4: 367–372.
Kitting, C.L. 1984. Selectivity by dense populations of small invertebrates foraging among seagrass blade surfaces. Estuaries 7: 276–288.
Lipcius, R.N., and W.T. Stockhausen. 2002. Concurrent decline of the spawning stock, recruitment, larval abundance, and size of the blue crab Callinectes sapidus in Chesapeake Bay. Marine Ecology Progress Series 226: 45–61.
Mansour, R.A. (1992). Foraging ecology of the blue crab, Callinectes sapidus Rathbun in lower Chesapeake Bay. Dissertation, Virginia Institute of Marine Science, College of William and Mary, Virginia
Nelson, W.G. 1979. Experimental studies of selective predation on amphipods: consequences for amphipod distribution and abundance. Journal of Experimental Marine Biology and Ecology 38: 225–245.
Nelson, W.G. 1980. A comparative study of amphipods in seagrasses from Florida to Nova Scotia. Bulletin of Marine Science 30: 80–89.
Orth, R.J., K.L. Heck Jr., and J. van Montfrans. 1984. Faunal communities in seagrass beds: a review of the influence of plant structure and prey characteristics in predator–prey relationships. Estuaries 7: 339–350.
Perkins-Visser, E., T.G. Wolcott, and D.L. Wolcott. 1996. Nursery role of seagrass beds: enhanced growth of juvenile blue crabs (Callinectes sapidus Rathbun). Journal of Experimental Marine Biology and Ecology 198: 155–173.
Peterson, B.J., and B. Fry. 1987. Stable isotopes in ecosystem studies. Annual Review of Ecology and Systematics 18: 293–320.
Phillips, D.L. 2001. Mixing models in analyses of diet using multiple stable isotopes: a critique. Oecologia 127: 166–170.
Phillips, D.L., and G.W. Gregg. 2003. Source partitioning using stable isotopes: coping with too many sources. Oecologia 136: 261–269.
Short, F.T., D.M. Burdick, and J.E. Kaldy. 1995. Mesocosm experiments quantify the effects of eutrophication on eelgrass, Zostera marina. Limnology and Oceanography 40: 740–749.
Stoner, A.W., and B.A. Buchanan. 1990. Ontogeny and overlap in the diets of four tropical Callinectes species. Bulletin of Marine Science 46: 3–12.
Tagatz, M.E. 1968. Biology of the blue crab, Callinectes sapidus Rathbun, in the St. Johns River, Florida. Fisheries Bulletin 67: 17–33.
Teixeira, R.L., and J.A. Musick JA. 1994. Trophic ecology of two congeneric pipefishes (Syngnathidae) of the lower York River, Virginia. Environmental Biology of Fishes 43: 295–309.
Thayer, G.W., P.L. Parker, M.W. LaCroix, and B. Fry. 1978. The stable carbon isotope ratio of some components of an eelgrass, Zostera marina, bed. Oecologia 35: 1–12.
Valentine, J.F., and J.E. Duffy. 2006. The central role of grazing in seagrass ecology. In Seagrasses: biology, ecology and conservation, ed. A.W.D. Larkum, R.J. Orth, and C.M. Duarte, 463–501. Dordrecht: Springer.
van Montfrans, J., R.L. Wetzel, and R.J. Orth. 1984. Epiphyte–grazer relationships in seagrass meadows: consequences for seagrass growth and production. Estuaries 7: 289–309.
Virnstein, R.W. 1978. Predator caging experiments in soft sediments: caution advised. In Estuarine interactions, ed. M.L. Wiley, 261–273. New York: Academic.
Wetzel, R.L., and H.A. Neckles. 1986. A model of Zostera marina L. photosynthesis and growth: simulated effects of selected physical–chemical variables and biological interactions. Aquatic Botany 26: 307–323.
Williams, S.W., and K.L. Heck Jr. 2001. Seagrass communities. In Marine community ecology, ed. M. Bertness, S. Gaines, and M. Hay, 317–337. Sunderland: Sinauer.
Zimmerman, R., R. Gibson, and J. Harrington. 1979. Herbivory and detritivory among gammaridean amphipods from a Florida seagrass community. Marine Biology 54: 41–47.
Acknowledgments
We thank J. Paul Richardson, Rachael E. Blake, Romuald Lipcius, Paul Gerdes, and others for help and advice with field and lab work, and we thank David Harris and the staff of the UC Davis Stable Isotope Facility for invaluable sample processing services. This work was supported by grant #XXXXXX to J.E. Duffy. This is VIMS contribution #XXXX.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Douglass, J.G., Emmett Duffy, J. & Canuel, E.A. Food Web Structure in a Chesapeake Bay Eelgrass Bed as Determined through Gut Contents and 13C and 15N Isotope Analysis. Estuaries and Coasts 34, 701–711 (2011). https://doi.org/10.1007/s12237-010-9356-4
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12237-010-9356-4