Predation by the black-clawed mud crab,Panopeus herbstii, in Mid-Atlantic salt marshes: Further evidence for top-down control of marsh grass production
Although top-down control of plant growth has been shown in a variety of marine systems, it is widely thought to be unimportant in salt marshes. Recent caging experiments in Virginia and Georgia have challenged this notion and shown that the dominant marsh grazer (the periwinkle,Littoraria irrorata) not only suppresses plant growth, but can denude marsh substrate at high densities. In these same marshes, our field observations suggest that the black-clawed mud crab,Panopeus herbstii, is an abundant and potentially important top-down determinant of periwinkle density. No studies have quantitatively examinedPanopeus distribution or trophic interactions in marsh systems, and its potential impacts on community structure remained unexplored. We investigated distribution and feeding habits ofPanopeus in eight salt marshes along the Mid-Atlantic seashore (Delaware-North Carolina). We found that mud crabs were abundant in tall (4–82 ind m−2), intermediate (0–15 ind m−2), and short-form (0–5 ind m−2)Spartina alterniflora zones in all marshes and that crab densities were negatively correlated with tidal height and positively correlated with bivalve density. Excavation of crab lairs r⇍utinely produced shells of plant-grazing snails (up to 36 lair−1) and bivalves. Lab experiments confirmed that mud crabs readily consume these abundant marsh molluscs. To experimentally examine potential community effects of observed predation patterns, we manipulated crab and periwinkle densities in a 1-mo field experiment. Results showed thatPanopeus can suppress gastropod abundance and that predation rates increase with increasing snail density. In turn, crab suppression of snail density reduces grazing intensity on salt marsh cordgrass, suggesting presence of a trophic cascade. These results indicate that this previously under-appreciated consumer is an important and indirect determinant of community structure and contribute to a growing body of evidence challenging the long-standing notion that consumers play a minor role in regulating marsh plant growth.
KeywordsSalt Marsh Marsh Surface Carapace Width Oyster Shell Oyster Reef
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Ambrose, W. G.
, Jr. 1984. Role of predatory infauna in structuring marine soft-bottom communities.Marine Ecology Progress Series
Belsovsky, G. E.
1985. Optimal foraging and community structure: Implications for a guild of generalist grassland herbivores.Oecologia
Bertness, M. D.
1984. Ribbed mussels andSpartina alterniflora
production in a New England salt marsh.Ecology
Bertness, M. D., G. Trussell, P. J. Ewanchuk
, andB. R. Silliman
. 2003. Testing for Alternate Stable States on Maine Rocky Shores.Ecology
Daiber, F. C.
1982. Animals of the Tidal Marsh. Van Nostrand Reinhold Company, New York.Google Scholar
Duffy, J. E.
andM. E. Hay
. 2001. Ecology and evolution of marine consumer-prey interactions, p. 131–157.In
M. Bertness, M. E. Hay, and S. D. Gaines (eds.), Marine Community Ecology. Sinauer Press, Sunderland, Massachusetts.Google Scholar
Estes, J. A.
. 1974. Sea otters: Their role in structuring nearshore communities.Science
Fell, E. P., N. C. Olmstead, E. Carlson, W. Jacob, D. Hitchcock
, andG. Silber
. 1982. Distribution and abundance of macroinvertebrates on certain Connecticut tidal marshes, with emphasis on dominant molluscs.Estuaries
Hay, M. E.
1984. Patterns of fish and urchin grazing on Caribbean reefs: Are previous results typical?Ecology
, Jr.K. L.
andJ. F. Valentine
. 1995. Sea urchin herbivory: Evidence for long-lasting effects in subtropical seagrass meadows.Journal of Experimental Biology and Ecology
Holmquist, J. G., G. V. N. Powell
, andS. M. Sogard
. 1989. Decapod and stomatopod communities of seagrass-covered mud banks in Florida Bay: Inter-and intra-bank heterogeneity with special reference to isolated subenvironments.Bulletin of Marine Science
Kneib, R. T.
andC. A. Weeks
. 1990. Intertidal distribution and feeding habits of the mud crab,Eurytium limosum
Knudsen, J. W.
1960. Aspects of the ecology of the California pebble crabs (Crustacea: Xanthidae).Ecological Monographs
: 30:166–185.CrossRefGoogle Scholar
Lee, S. Y.
andR. T. Kneib
. 1994. Effects of biogenic structure on prey consumption by the xanthid crabsEurytium limosum
in a salt marsh.Marine Ecology Progress Series
Lewis, D. B.
andL. A. Eby
. 2002. Spatially heterogenous refugia and predation risk in intertidal salt marshes.Oikos
Lipcius, R. W.
. 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
1978. Plant species diversity in a marine intertidal community: Importance of herbivore food preference and algal competitive abilities.American Naturalist
McDermott, J. J.
1960. The predation of oysters and barnacles by crabs on the family Xanthidae.Proceedings from the Pennsylvania Academy of Sciences
1982. Divergent life history patterns in the cooccurring intertidal crabsPanopeus herbstii
(Crustacea: Brachyura: Xanthidae).Marine Ecology Progress Series
McQueen, D. J., M. R. S. Johnannes, J. R. Post, T. J. Stewart
, andD. R. S. Lean
. 1989. Bottom-up and top-down impacts on freshwater pelagic community structure.Ecological Monographs
Menge, B. A.
1976. Organization of the New England rocky intertidal community: Role of predation, competition, and environmental heterogeneity.Ecological Monographs
Mense, D. J., M. H. Posey, T. West
, andF. Kincheloe
. 1995. Settlement of brachyuran postlarvae along the North Carolina coast.Bulletin of Marine Science
Meyer, D. L.
1994. Habitat partitioning between the xanthid crabsPanopeus herbstii
on intertidal oyster reefs (Crassostrea virginia
) in southeastern North Carolina.Estuaries
Mithsch, W. J.
andJ. G. Gosselink
. 2002. Wetlands. Van Nostrand Reinhold. New York.Google Scholar
1999. Community Ecology. Blackwell, Ltd., Malden, Massachusetts.Google Scholar
Pace, M. L., J. J. Cole, S. R. Carpenter
, andJ. F. Kitchell
. 1999. Trophic cascades revealed in diverse ecosystems.Trends in Ecology and Evolution
1966. Food web complexity and species diversity.American Naturalist
Paine, R. T.
1980. Food webs: Linkage, interaction strength, and community infrastructure.Journal of Animal Ecology
Posey, M. H.
andA. H. Hines
. 1991. Complex predator-prey interactions within an estuarine benthic community.Ecology
1980. Predator-prey relationships between the mud crabPanopeus herbstii
, the blue crab,Callinectes sapidus
and the Atlantic ribbed musselGeukensia denissa
.Estuarine, Coastal and Marine Science
Silliman, B. R.
1999. Effects of nutrient enrichment and periwinkle grazing onSpartina alterniflora
growth. Master’s Thesis, University of Virginia. Charlottesville, Virginia.Google Scholar
Silliman, B. R.
andM. D. Bertness
. 2002. A trophic cascade regulates salt marsh primary production.Proceedings From the National Academy of Sciences
Silliman, B. R.
. 2003. Underestimation ofSpartina
production in Western Atlantic salt marshes: Marsh in vertebrates eat more than just detritus.Oikos
Silliman, B. R.
andJ. C. Zieman
. 2001. Top-down control ofSpartina alterniflora
production by periwinkle grazing in a Virginia marsh,Ecology
Strong, D. R.
1992. Are trophic cascades all wet? Differentiation and donor-control in speciose ecosystems.Ecology
Teal, J. M.
1958. Distribution of fiddler crabs in Georgia salt marshes.Ecology
Teal, J. M.
1962. Energy flow in the salt marsh ecosystem of Georgia.Ecology
Trussell, G., P. J. Ewanchuk
, andM. D. Bertness
. 2002. Field evidence of trait-mediated indirect interactions in a rocky intertidal food web.Ecology Letters
Welch, J. M.
andC. E. Epifanio
. 1994. Recruitment in larval Xanthid crabs: Is prey abundance important? Master’s Thesis, University of Delaware, Lewes, Delaware.Google Scholar
Whetstone, J. M.
andA. G. Eversole
. 1981. Effects of size and temperature on mud crab,Panopeus herbstii
, predation on hard clams,Mercenaria mercenaria
Williams, A. B.
1984. Shrimps, Lobsters and Crabs of the Atlantic of the Eastern United States, Maine to Florida, Smithsonian Institution Press, Washington, D.C.Google Scholar
Wrona, A. B., R. G. Wiegert
, andT. D. Bishop
. 1995. Initial report of settlement patterns of Brachyuran megalopae at Sapelo Island, GA, U.S.A..Bulletin of Marine Science
Zieman, J. C.
1982. The ecology of the seagrasses of south Florida: A community profile. Biological Services Program FWS/OBS-82/85. U.S. Fish and Wildlife Service, Washington, D.C.Google Scholar
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