Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"Hydroacoustics"”.
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Use Of Multi-Gear Sampling To Improve Abundance Estimates Of Demersal Coregonids In The Laurentian Great Lakes
… useful when performing stock assessments because hydroacoustics provide rapid spatial coverage as well as lower size and species selectivity compared to other assessment methods. The objective of this study is to develop an accurate hydroacoustic sampling method for measuring the abundance and …
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Habitat Mapping and Predator-Prey Dynamics in Ohio Resevoirs
… were tagged with a radio tag for location. Hydroacoustics were used to map prey densities and biomass, and to map substrate type. Akaike's Information Criterion (AIC) was used to determine which habitat variables are the most important for explaining the presence or absence of saugeye. In …
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Behavioral Responses of Rainbow Smelt to Sensory Deterrent Systems
… strobe lights. For objectives 1 and 2, splitbeam hydroacoustics were used to assess the effectiveness of the SPA and the strobe light system by comparing proximal densities of rainbow smelt before and after a deterrent method was activated. For objective 3, limnological data such as chlorophyll-a, …
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Development of an OpenFOAM Solver for Hydroacoustic Simulations: An Application for Acoustic Fish Deterrence
This project aims to develop computational tools for analyzing an underwater acoustic system designed to deter invasive fish species in the Mississippi River Basin. It leverages an established numerical framework (OpenFOAM) and deals with understanding how to model the system. The study prioritizes …
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Analysis of the Trophic Support Capacity of Smith Mountain Lake, Virginia, for Piscivorous Fish
This investigation examined the adequacy of the forage base to meet current demand of piscivores in Smith Mountain Lake, Virginia. Surplus production, or the maximum sustainable supply, of alewife (Alosa pseudoharengus) and gizzard shad (Dorosoma cepedianum) were determined using data on the …
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Fish Assemblage Structure, Distribution, and Trophic Ecology at Northwestern Gulf of Mexico Banks
The northwest Gulf of Mexico (Gulf) shelf-edge banks both provide unique hard bottom habitat and support the northernmost coral reefs on the North American continental shelf in a region that is generally characterized by low relief, soft sediments. The habitat value of many of these banks has led …
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An Approach For Use of Dual Frequency Identification Sonar (DIDSON) to Quantify Behavioral Aspects of Piscivory at Ecologically Relevant Time and Space Scales
<p>Predator-prey interactions of large vagile fishes are difficult to study in the ocean due to limitations in the space and time requirements for observations. Small-scale direct underwater observations by divers (<10m >radius) and large-scale hydroacoustic surveys (10s - 100s km2) are traditional …
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Reef fish demographics on Louisiana artificial reefs : the effects of reef size on biomass distribution and foraging dynamics
Understanding the role that habitat plays in the life history of reef-associated fishes is particularly significant given the dramatic increase in the number of artificial reefs deployed in coastal ecosystems over the past 50 years. In the Gulf of Mexico, the oil and gas industry has added a …
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Characterization of Natural and Anthropogenic Seabed Features in the Southwestern Baltic Sea
The marine environment faces threats from human activities that can disturb the seabed and may threaten the proper functioning of marine ecosystems. A sustainable balance between human uses and seabed integrity requires knowledge of the seabed's physical characteristics, benthic habitat …
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From meander bend to oxbow lake: morphodynamics and sedimentology of chute cutoffs
Chute cutoffs are common features of meandering channels. The development of a chute cutoff locally shortens and straightens a meandering river channel, excavating a large volume of floodplain sediment as the chute channel deepens and widens. Bar development at the upstream and downstream ends of …