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dc.contributor.authorFuchs, Heidi L.  Concept link
dc.coverage.spatialBarnstable Harbor, Mass.
dc.date.accessioned2007-06-18T15:21:04Z
dc.date.available2007-06-18T15:21:04Z
dc.date.issued2005-09
dc.identifier.urihttps://hdl.handle.net/1912/1710
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2005en
dc.description.abstractThe goals of this thesis were to quantify the behavior of gastropod larvae (mud snails Ryanassa obsoleta) in turbulence, and to investigate how that behavior affects larval supply in a turbulent coastal inlet. Gastropod larvae retract their velums and sink rapidly in strong turbulence. Turbulence-induced sinking would be an adaptive behavior if it resulted in increased larval supply and enhanced settlement in suitable coastal habitats. In laboratory experiments, mud snail larvae were found to have three behavioral modes: swimming, hovering, and sinking. The proportion of sinking larvae increased exponentially with the turbulence dissipation rate over a range comparable to turbulence in a tidal inlet, and the mean larval vertical velocity shifted from upward to downward in turbulence resembling energetic nearshore areas. The larval response to turbulence was incorporated in a vertical advection-diffusion model to characterize the effects of this behavior on larval supply and settlement in a tidal channel. Compared to passive larvae, larvae that sink in turbulence have higher near-bed concentrations throughout flood and ebb tides. This high larval supply enables behaving larvae to settle more successfully than passive larvae in strong currents characteristic of turbulent tidal inlets. A study was conducted at Barnstable Harbor, MA to estimate the responses of larvae to turbulence in the field. Gastropod larvae from different coastal environments had genus-specific responses to turbulence, suggesting that larvae use turbulence for large-scale habitat selection. On ebb tides, mud snail larvae had a similar response to turbulence as in the laboratory, with greater sinking velocities in strong turbulence. Behavior estimates differed for flood and ebb tides, indicating that additional physical cues influence behavior. Turbulence-induced sinking behavior would enhance retention and promote settlement of mud snail larvae in habitats like Barnstable Harbor.en
dc.description.sponsorshipFinancial support was provided by a National Science Foundation Graduate Research Fellowship, the WHOI Academic Programs Office, a WHOI Coastal Ocean: Institute grant, a WHOI Mellon independent study grant to L. S. Mullineaux and M; G. Neubert, a Sea Grant New Initiative grant (Grant No. NA16RG2273, project no. R/O-38-PD), the WHOI Biology department, and the Rinehart Coastal Research Center.en
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen
dc.relation.ispartofseriesWHOI Thesesen
dc.subjectBenthic animalsen_US
dc.subjectLarvaeen_US
dc.subjectDispersalen_US
dc.subjectTurbidity currentsen_US
dc.titleBiophysical coupling between turbulence, veliger behavior, and larval supplyen
dc.typeThesisen
dc.identifier.doi10.1575/1912/1710


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