Estimating Gulf of Maine zooplankton distributions using multiple frequency acoustic, video and environmental data
Warren, Joseph D.
MetadataShow full item record
LocationGulf of Maine
This thesis develops methods useful for estimating zooplankton distributions in the field by combining acoustic models and an integrated set of field data. The accuracy of existing scattering models for fluid-like and elastic-shelled animals is determined by analysis of scattering data from individual animals in a laboratory tank. Results indicate that simple two-ray scattering models are accurate and allow predictions of size or orientation of an animal to be made for certain animal orientations. A model for gas-bearing zooplankton is compared with in situ multiple frequency acoustic measurements from siphonophores. Estimates of the numerical density of these animals are made using echo integration data from a scientific echo-sounder. Multiple frequency acoustic scattering data from a survey of an internal wave are analyzed to determine the contributions from biological and physical sources. Net tow data provide information about biological scatterers while temperature and salinity profiles are used with a theoretical model to predict contributions from physical sources. Results indicate that scattering from physical sources is comparable to that from biological sources in certain regions and that spectra may be used to distinguish these sources. Improved estimates of biomass from acoustic scattering data were made by accounting for the scattering contributions from physical sources. This is the first work to quantify the scattering contributions from biological and physical sources of scattering in a field study.
Submitted 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 February 2001
Showing items related by title, author, creator and subject.
Brooks, James Ray (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1979-08)The flow fields entering intake forms oriented into a steady flume flow has been observed and quantified. This data is applied to a model of zooplankton sampler performance, to predict the fraction of the sampled ...
Martin Traykovski, Linda V. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-02)Work on the forward problem in zooplankton bioacoustics has resulted in the identification of three categories of acoustic scatterers: elastic-shelled (e.g. pteropods), fluid-like (e.g. euphausiids), and gas-bearing (e.g. ...
Physical processes and zooplankton distribution in the Great South Channel : observational and numerical studies Epstein, Ari W. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1995-06)This thesis addresses the question, "How do small-scale physics and biology combine to produce dense aggregations of certain species of zooplankton in the Great South Channel (GSC) of the Gulf of Maine?" The thesis ...