Date of Award

5-2011

Level of Access Assigned by Author

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Oceanography

Advisor

Andrew J. Pershing

Second Committee Member

Daniel Bourgault

Third Committee Member

Lewis S. Incze

Abstract

The transfer of energy to higher trophic levels often occurs at hot-spots where prey are aggregated into dense patches. These hot-spots are often associated with specific oceanographic or bathymetric features. On offshore banks in the Gulf of Maine, internal waves appear to play a dominant role in concentrating an otherwise patchy but still dilute distribution of euphausiids, creating feeding opportunities for whales, fish, and seabirds. To investigate the proposed relationship between internal waves and krill dynamics, a two-dimensional, nonhydrostatic internal wave model was combined with an idealized bank system based on Platts Bank in the Gulf of Maine. Krill movements induced by the propagation and shoaling of large-amplitude internal waves over the bank were calculated by populating the model flow fields with particles and individually tracking their positions. We examined the influence of vertical density structure on the variability in hot-spot activity to determine ideal and limiting scenarios in which krill could be concentrated in the presence of internal waves.

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