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dc.contributor.advisorWebster, Donald R.
dc.contributor.authorJung, Seongyu
dc.date.accessioned2016-01-07T17:24:52Z
dc.date.available2016-01-07T17:24:52Z
dc.date.created2015-12
dc.date.issued2015-12-08
dc.date.submittedDecember 2015
dc.identifier.urihttp://hdl.handle.net/1853/54377
dc.description.abstractInternal waves are ubiquitous features in coastal marine environments and have been observed to mediate vertical distributions of zooplankton in situ. Internal waves create fine-scale hydrodynamic cues that copepods and other zooplankton are known to sense, such as fluid density gradients and velocity gradients (quantified as shear deformation rate). The role of copepod behavior in response to cues associated with internal waves is largely unknown. The objective is to provide insight to the bio-physical interaction and the role of biological versus physical forcing in mediating organism distributions. We constructed a laboratory-scale internal wave apparatus to facilitate fine-scale observations of copepod behavior in flows that replicate in situ conditions of internal waves in a two-layer stratification. Three cases were chosen with density jump of 0.75, 1.0, and 1.5 sigma-t units. Analytical analysis of the two-layer system provided guidance to the target forcing frequency needed to generate a standing internal wave with a single dominate frequency of oscillation. Flow visualization and signal processing of the interface location were used to quantify the wave characteristics. The results show a close match to the target wave parameters. Marine copepod (mixed population of Acartia tonsa, Temora longicornis, and Eurytemora affinis) behavior assays were conducted for three different physical arrangements: (1) no density stratification, (2) stagnant two-layer density stratification, and (3) two-layer density stratification with internal wave motion. Digitized trajectories of copepod swimming behavior indicate that in the control (case 1) the animals showed no preferential motion in terms of direction. In the stagnant density jump treatment (case 2) copepods preferentially moved horizontally, parallel to the density interface. In the internal wave treatment (case 3) copepods demonstrated orbital trajectories near the density interface. Further analysis showed that the copepods swim closer to the interface in the presence of internal waves.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectInternal waves
dc.subjectThin layers
dc.subjectCopepods
dc.titleImplementation of internal wave apparatus for copepod behavioral assays
dc.typeThesis
dc.description.degreeM.S.
dc.contributor.departmentCivil and Environmental Engineering
thesis.degree.levelMasters
dc.contributor.committeeMemberHaas, Kevin A.
dc.contributor.committeeMemberYen, Jeannette
dc.date.updated2016-01-07T17:24:52Z


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