Influence of habitat complexity in structuring species-specific interactions and trophic linkages on oyster reefs of southeastern North Carolina
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Joseph M. Sonnier (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Stephen Kinsey
Abstract: Species interactions influencing the strength of trophic linkages play a key role in
structuring communities. Although the importance of these interactions has been
recognized, currently there are relatively few studies characterizing the role of habitat in
moderating these interactions, especially in marine environments. Habitat complexity
that provides refuge for some organisms may alter interactions between species with
consequences for community composition. Recently created oyster reefs of differing
complexity in southeastern North Carolina provide an excellent opportunity to test the
hypothesis that increased habitat complexity modifies predator-prey interactions leading
to direct and indirect effects in the oyster reef community. The common mud crab,
Panopeus herbstii, is an abundant intermediate predator living within oyster reefs feeding
on bivalves such as oyster spat, Crassostrea virginica, and ribbed mussels, Geukensia
demissa, and is prey for other species such as blue crabs, Callinectes sapidus, and larger
fishes. The goal of this study was to determine the direct and indirect effects of oyster
complexity on mud crab populations (density, distribution, feeding, and survival) in a
field setting and mud crab: bivalve (predator-prey) dynamics in the presence and absence
of a top predator, the blue crab in a laboratory setting. Mud crab density was
significantly greater in areas of high habitat complexity during both field and lab studies.
Tethering trials indicated predation on mud crabs increased as oyster reef complexity
decreased with highest predation rates in open sand. However, highest predation on mud
crabs occurred in open sand areas along the edge of high complexity reefs compared to
sand areas distant from a reef. Laboratory studies indicated mud crab predation on oyster
spat and mussels was greater in high complexity oyster patches, but mussels were preferred over oyster spat. The presence of a top predator had differing effects on mud
crab predation of oyster spat and ribbed mussels. Predation on oyster spat was reduced in
high complexity patches, whereas predation on ribbed mussels was reduced in low
complexity patches when blue crabs were present. A potential positive feedback was
observed where high complexity oyster habitat provide increased settlement habitat for
mussels and mussels provide an alternate, preferred prey source reducing predation
pressure on oyster spat. This study demonstrated the multifaceted role of habitat
complexity in modifying trophic interaction within a multi-prey system.
Influence of habitat complexity in structuring species-specific interactions and trophic linkages on oyster reefs of southeastern North Carolina
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Created on 1/1/2009
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
- Language: English
- Date: 2009
- Keywords
- Bivalves--Effect of habitat modification on, Habitat (Ecology)--North Carolina, Mussels--Effect of predation on--North Carolina, Oyster culture--North Carolina, Oysters--Effect of predation on--North Carolina, Predation (Biology)
- Subjects
- Oyster culture -- North Carolina
- Habitat (Ecology) -- North Carolina
- Oysters -- Effect of predation on -- North Carolina
- Mussels -- Effect of predation on -- North Carolina
- Predation (Biology)
- Bivalves -- Effect of habitat modification on