Thesis (Ph. D.)--Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution, 1982. / Vita. Includes bibliographical references (p. 217-223).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 143-158).

Sponges are filter feeders that lack nerves and muscle but are nonetheless able to respond to changes in the ambient environment to control their feeding current. Cellular sponges undergo coordinated contractions that effectively expel debris. Syncytial sponges propagate action potentials through their tissue, causing immediate flagellar arrest. Understanding the basis of this coordination in sponges is of interest for the insight it provides on mechanisms of coordination in early branching animals. However, when I began this thesis no ion channels had been described from the Porifera. I adopted a multifaceted approach to studying the conduction system of sponges. This included cloning and characterizing potassium channels as a means to understanding the underlying ionic currents, and monitoring regulation of the sponge feeding current in response to environmental stimuli. The latter experiments provided a functional context. The glass sponges Rhabdocalyptus dawsoni and Aphrocallistes vastus arrest feeding in response to mechanical disturbance and to sediment in the incurrent water suggesting a protective role. Monitoring patterns of feeding current arrests also revealed several features of the glass sponge conduction system: pacemaker activity, mechanosensitivity, distinct excitability thresholds, and tolerance to repeated stimuli. With access to the genome of the demosponge Amphimedon queenslandica I have also cloned and characterized the first sponge ion channels. Inward rectifier potassium (Kir) channels were prioritized for their role in regulating excitability. Kir channels cloned from A. queenslandica shared critical residues and a strong rectifying phenotype with Kir channels typically expressed in excitable cells. A variety of potassium channels from A. queenslandica indicate great diversity and a foundation for coordination at the dawn of the Metazoa / Physiology, Cell and Developmental Biology

Thesis (M.S.)--Oregon State University, 1977. / Typescript (photocopy). Date thesis presented: June 3, 1976. Includes bibliographical references. Also available on the World Wide Web.

Cold seeps are areas of high biomass in the deep-sea, the impacts of these food-rich environments upon the sediment community is unknown in the Gulf of Mexico. The structure and function of benthic communities was investigated at food-rich and food-limited sites on the northern Gulf of Mexico continental slope. Cold seeps were richer in macrofauna densities and total sediment respiration, but were poorer in biomass and taxa diversity than normal slope communities. Decreased diversity is seen at most chemosynthetic communities and suggests a competition for resources. The spatial extent of these results at seeps is unknown and may be a localized, bioenhancement effect caused by seeping fluids.

Runoff from road construction and maintenance sites is responsible for erosion and deposition of sediments in the receiving water bodies. In addition to soil particles from erosion, runoff also transports other pollutants such as rubber, toxic metals, automobile fluids, car exhausts (which settle with the rain), pesticides, fertilizers, and other debris. Compost has been used effectively as a valuable soil amendment to aid plant growth. Berms (mounds) of compost placed at the top or bottom of steep slopes can be used to slow the velocity of water and provide additional protection for receiving waters. However, a downside of the application of composted organic material is the potential degradation of runoff water quality. Overloading with nitrogen and phosphorus causes eutrophication, which reduces the suitability of waterways for beneficial uses. A field testing of the berms coupled with a laboratory analysis of the testing water will provide a basis for the impact of the compost berms on the runoff water quality. The study of the impact of compost on the runoff water quality was investigated. The objective of this study was to evaluate the performance of berms made from various materials such as dairy manure compost, yard waste compost and composted bio-solids mixed with wood chips in a ratio of 50:50 on the runoff water quality, as well as, the sediment removal efficiencies. Field tests were performed on the berms to simulate conventional rainfall runoff and the tested water was collected as time-weighted samples and analyzed in the laboratory. Several variables were investigated during this study. Results of this investigation demonstrated that the effectiveness of this application was hampered by the structural instability of the berm. A 100% failure rate was observed in the berms tested. Optimum performance was observed in yard waste compost berms, which introduced the least amount of contaminants into the water. However, some masking effect could be present due to berm failures. In fact, the actual sediment removal by the berms could not be determined. The study of compost filter berms showed some evidence of the existence of first flush effect.

The objective of this research is to identify the circulation patterns of the water and sediment fluxes in coastal and estuarine zones, where the shoaling processes correlate with tide generating flow patterns. The research provides a better understanding of the characteristics of spatial and temporal variability of currents. An important deviation from previous research is the inclusion of the baroclinic term, which becomes very important in density driven flows. The understanding of this process provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model is used to calculate the water circulation. The model is based on the three-dimensional (3D) version of Advanced Circulation (AD-CIRC) Hydrodynamic Model with extending the Sediment Transport module. The model is based on the finite element method on unstructured grids. The output of the hydrody-namic model is used to estimate spatial and temporal advections, dispersions and bottom shear stress for the erosion, suspension, deposition and transport of sediment. The model development includes extending the existing three-dimensional (3D) ADCIRC Model with (1) baroclinic forcing term and (2) transport module of suspended and soluble materials. The transport module covers the erosion, material suspension and deposition processes for both cohesive and non-cohesive type sediments. The inclusion of the baroclinic demonstrates the potential of over or underpredicting the total net transport of suspended cohesive sediment under influence of currents. The model provides less than 6% error of theoretical mass conservation for eroded, suspended and deposited sediment material. The inclusion of the baroclinic term in stratified water demonstrates the prevailing longshore sediment transport. It is shown that the model has an application to the transport of the cohesive sediments from the mouth of the Mississippi River along the north shore of the Gulf of Mexico towards and along the Texas coast. The model is also applicable to determine the design erosion thickness of a cap for isolating contaminated dredged material and to evaluate the appro-priate grain size of cap sediments to minimize the erosion.

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate. The sediment was also analysed for total-P and organic P by drying, dispersion in a mortar and sieving followed by boiling in HCl. Analysis of phosphate-P in all extracts was done with an acid molybdate solution and ascorbic acid, forming a blue complex that was measured spectrophotometrically. There was no significant relationship between soluble P or soluble total-P and the proportion of clay in the sediment samples. This was also the case for total-P and organic-P. Generally, the levels of phosphorus in the sediment were low, which may result from too deep sediment samples, causing the settled P-rich sediment to be diluted by the terrestrial soil underneath the wetland. There was a low proportion of clay in the sediment (4 – 18 %), which made it difficult to detect any correlation with soluble-P content. When omitting the samples at the inlet (which were more influenced by vegetation than the others), a significant positive correlation between percentage of clay and distance from the inlet was detected, suggesting that clay particles were settling in the wetland.

The Gaoping Slope, off the south west coast of Taiwan, is a tectonically active sedimentation environment attaining most of its sediment from the Gaoping River. This study examines sediment cores from two localities at 375 m and 495 m water depth by using X-radiography, Grain size- and 210Pb analysis, with the purpose of comparing the sedimentation environment at the two sites and examine how they were both affected by high sediment delivery during typhoon Morakot.The shallow site has coarse bioturbated sediment, whereas the deeper site had laminated fine sediment containing high amounts of organic material. Both localities display a 13-20 cm thick recently deposited layer in the cores taken after typhoon Morakot. The layers are characterized by coarsening-fining sequences. All cores show cyclicity in the grain size data.We suggest that the shallow station has a more energetic environment, affected by wave reworking, tides, and alongshore currents supplying riverine material from the Gaoping river. The deep site has a calmer sedimentation environment dominated by hemipelagic settling of suspended material. The recent accumulated deposits are most likely hyperpycnites from density driven hyperpycnal flows, originally caused by canyon overflows in the Gaoping- and the Kaohsiung canyon during the typhoon. The strata found at the Gaoping slope is a result of submarine mass transport of sediment, and reflect the interaction between annual seasons and extreme events triggered by typhoons and earthquakes - eroding, transporting, and depositing sediment in the area.

An expansive panel of well exposed (periglacial) strata of the Upper Kaza Group permitted a detailed study of the stratal architecture of proximal basin floor deposits in the Neoproterozoic Windermere turbidite system. Detailed stratigraphic and petrographic analyses identified six lithofacies: poorly-sorted, clast-rich mudstone (F1), thin-bedded siltstone and mudstone (F2), thick-bedded, massive sandstone (F3), medium-scale, cross-stratified sandstone (F4), mudstone-clast breccia (F5), and medium-bedded turbidites (F6). The spatial distribution of these facies identify five architectural elements: heterolithic feeder channel deposits (FA1), thin-bedded intralobe turbidites (FA2), terminal splay deposits (FA3), distributary channel deposits (FA4), and isolated scours (FA5). FA 1-4 are genetically related and form the basic building blocks of large-scale basin floor depositional lobes. FA 5, which is isolated to the stratigraphic top of the study area, is interpreted to have formed in a base-of-slope setting, and its superposition on FA 1-4 suggests the long-term progradation of the Windermere turbidite system.