The ecology of blue crab (Callinectes sapidus) megalopae in the Mission-Aransas Estuary, Texas : salinity, settlement, and transport

dc.contributor.advisorBuskey, Edward Joseph, 1952-
dc.creatorBittler, Kimberly Marieen
dc.date.accessioned2014-03-24T19:14:24Zen
dc.date.accessioned2017-05-11T22:48:51Z
dc.date.available2017-05-11T22:48:51Z
dc.date.issued2013-12en
dc.date.submittedDecember 2013en
dc.date.updated2014-03-24T19:14:24Zen
dc.descriptiontexten
dc.description.abstractBlue crabs are a widely distributed estuarine species with broad economic and ecological importance. Several studies have linked blue crabs to freshwater inflows, but the precise nature of this link is still uncertain, as blue crabs have a complex life cycle that utilizes both marine and estuarine environments. One potential link between blue crabs and freshwater inflows is during recruitment, when megalopae developing offshore return to estuaries before molting into juvenile crabs. Megalopae swim during the flood tide to ensure delivery into and farther up estuaries. The behaviors regulating selective tidal stream transport (STST) on the flood tide were originally studied in North Carolina in an estuary with regular freshwater inflows and a strong salinity gradient. The model of STST was re-examined in the Mission-Aransas, an estuary with episodic freshwater inflows and salinity gradients ranging from normal estuarine conditions to hypersaline during droughts. The behavioral responses of megalopae to a range of rates of salinity increase were tested, and then modeled onto rates of salinity change observed in the field to determine the theoretical ecological consequences of STST for blue crab populations in the Mission-Aransas Estuary. To validate the ecological trends predicted by the behavioral model of STST, a simple, long-term data set reflecting changes in megalopae abundance is needed. Hog’s hair collectors are a simple and widely used method of quantifying abundance of brachyuran megalopae, including blue crabs. However, the efficiency of hog’s hair collectors in sampling for megalopae is unknown. Several studies have reported poor correlations between settlement on hog’s hair collectors, transport, and abundance of megalopae in the plankton due to disparate temporal scales and potentially turbulence-driven decoupling. Each of these issues were addressed in field and flume experiments, which were used to develop a model for interpreting settlement on hog’s hair collectors in terms of transport and planktonic abundance.en
dc.description.departmentMarine Scienceen
dc.embargo.lift12/1/2014en
dc.embargo.terms12/1/2014en
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/2152/23638en
dc.subjectCallinectes sapidusen
dc.subjectBlue craben
dc.subjectSelective tidal stream transporten
dc.subjectSalinityen
dc.subjectDroughten
dc.subjectHog's hair collectoren
dc.subjectSettlementen
dc.subjectBehavioren
dc.subjectFreshwater inflowsen
dc.subjectMegalopaeen
dc.titleThe ecology of blue crab (Callinectes sapidus) megalopae in the Mission-Aransas Estuary, Texas : salinity, settlement, and transporten
dc.typeThesisen

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