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Full-Text Articles in Physical Sciences and Mathematics

Mechanics Of Burrowing In Muddy Sediments, Kelly M. Dorgan Dec 2007

Mechanics Of Burrowing In Muddy Sediments, Kelly M. Dorgan

Electronic Theses and Dissertations

Marine muds are elastic solids through which animals move by propagating a crack-shaped burrow. Dilations previously considered anchors serve to exert dorsoventral compressive stresses on the burrow walls that, through elastic behavior of the medium, focus strongly at the tip of the burrow. This focused stress breaks adhesive or cohesive bonds, propagating a crack for the animal to follow. The force exerted by the polychaete, Nereis virens, to propagate a crack has been measured in gelatin, an analogue of muddy sediment, through photoelastic stress analysis. Finite element analysis was used to convert measured forces to those exerted in natural sediments …


Assessment Of The Flame Angelfish (Centropyge Loriculus) As A Model Species In Studies On Egg And Larval Quality In Marine Fishes, Chatham K. Callan Aug 2007

Assessment Of The Flame Angelfish (Centropyge Loriculus) As A Model Species In Studies On Egg And Larval Quality In Marine Fishes, Chatham K. Callan

Electronic Theses and Dissertations

This project sought to determine if flame angelfish (Centropyge loriculus) could serve as models in examination of environmental and dietary effects on egg quality in marine fishes. Evaluation of 21 marine ornamental species identified flame angelfish as being amenable to egg quality research, due to their rapid conditioning and frequency of spawning. At the onset of this project, accidental copper introduction to broodstock systems required assays to determine the effects of copper exposure on survival and reproduction. Flame angelfish exhibited accute sensitivity to copper, as 60% of fish exposed to 0.25mg/L died within 12 hours of exposure. Likewise, fish exposed …


Remote Assessment Of 4-D Phytoplankton Distributions Off The Washington Coast, Brandon S. Sackmann May 2007

Remote Assessment Of 4-D Phytoplankton Distributions Off The Washington Coast, Brandon S. Sackmann

Electronic Theses and Dissertations

Satellite-based optical measurements were coupled with physical and optical measurements from Seaglider – a long-range autonomous glider – to study interactions between biological and physical processes off the coast of Washington, USA, and to evaluate space-time variability of regional phytoplankton and particle distributions. Using satellite ocean color data variability in near-surface chlorophyll a was characterized across a range of spatial and temporal scales ranging from 1 – 500 km and from days – years to assess region-wide responses by phytoplankton to changes in environmental conditions. Results from 1998 – 2002 revealed both strong negative and positive anomalies associated with lingering …


The Response Of A General Circulation Climate Model Tohigh Latitude Freshwater Forcing In The Atlantic Basinwith Respect Totropi, Victor Paulis Jan 2007

The Response Of A General Circulation Climate Model Tohigh Latitude Freshwater Forcing In The Atlantic Basinwith Respect Totropi, Victor Paulis

Electronic Theses and Dissertations

The current cycle of climate change along with increases in hurricane activity, changing precipitation patterns, glacial melt, and other extremes of weather has led to interest and research into the global correlation or teleconnection between these events. Examination of historical climate records, proxies and observations is leading to formulation of hypotheses of climate dynamics with modeling and simulation being used to test these hypotheses as well as making projections. Ocean currents are believed to be an important factor in climate change with thermohaline circulation (THC) fluctuations being implicated in past cycles of abrupt change. Freshwater water discharge into high-latitude oceans …


A Late Holocene Reconstruction Of Ocean Climate Variability In The Gulf Of Maine, Usa, Based On Calibrated Isotope Records And Growth Histories From The Long-Lived Ocean Quahog (Arctica Islandica L.), Alan D. Wanamaker Jan 2007

A Late Holocene Reconstruction Of Ocean Climate Variability In The Gulf Of Maine, Usa, Based On Calibrated Isotope Records And Growth Histories From The Long-Lived Ocean Quahog (Arctica Islandica L.), Alan D. Wanamaker

Electronic Theses and Dissertations

Understanding regional patterns of interannual to decadal-scale climate variability over the past 1000 years is critical for evaluating recently observed trends in atmosphere/ocean conditions, particularly in highly-productive ecosystems such as the Gulf of Maine (GOM) that are sensitive to minor changes in climate and/or changes in slope water input. To develop quantitative relationships between bivalve shell chemistry (d18Oc) and growing conditions, aquaculture-based experiments were developed using Mytilus edulis collected in the GOM and Greenland. These experiments yielded a highly accurate and precise paleothermometer [e.g., T °C = 16.28 (± 0.10) - 4.57 (± 0.15) {d18Oc VPBD – d18Ow VSMOW} + …