This work represents a first look at the general spatial distribution of trace metals and the inorganic carbon system in the surface waters of Tampa Bay. Tampa Bay's chemical environment bears many influences ranging from hydrological and geological to anthropogenic and meteorological. A large y-shaped estuary on the west-central side of the Florida Peninsula, Tampa Bay extends over 400 square miles and has a 2200 square mile watershed that includes extensive swamps, scrub, agricultural lands and densely urbanized areas. Reaching 37 miles from the northernmost point of Old Tampa Bay to the mouth of the estuary near the Sunshine Skyway Bridge, it is home to the largest port in Florida, and overall places 17th in the nation for tonnage. In addition to its ports, Tampa Bay supports the requirements of a broad range of industries including: ship building and repair, power generation, wastewater processing, development, and recreational and commercial fishing. The region experiences high rainfall during the summer and much reduced rainfall during the remaining portions of the year. The bay has a broad gradient of mixing intensities, with residence times ranging from 100+ days in Old Tampa Bay to less than 20 days at the mouth. Seventy-one percent of Tampa Bay's freshwater input is delivered by four primary rivers: the Hillsborough, Alafia, Manatee and Little Manatee; and the region is strongly influenced by spring outflow from the Floridan Aquifer. The largest river, the Hillsborough, spans 54 miles from the Green Swamp to its mouth in Hillsborough Bay. Samples were collected over a two-week period in January of 2013 along 13 sites on the Hillsborough River and 26 stations in Tampa Bay. Metal concentration analyses were conducted on twelve elements using inductively coupled plasma mass spectrometry (ICP-MS). These twelve elements included sodium, lithium, magnesium, calcium, strontium, barium, vanadium, molybdenum, manganese, nickel, antimony, and uranium. Within Tampa Bay, sodium, lithium, and magnesium exhibited strongly conservative behavior (showing simple two-end-member mixing). Calcium, strontium, molybdenum, and uranium show quasi-conservative behavior, with localized deviations from simple mixing of fresh water and seawater end members. The remaining elements showed variable behavior driven by solubility, redox reactions, and/or unique localized inputs based on local geology. Comparisons of baywater calcium concentrations and the concentrations of lithium, magnesium, strontium and barium revealed simple relationships that are promising for use in interpretations of otolith chemistry of teleosts and some agnatha (Campana, 1999; Carlström, 1963). Samples were collected from both the river and the bay for CO2 system analyses. Spectrophometric pH measurements were obtained using purified m-Cresol Purple (mCP) and the procedures of Liu et al. (2011). Dissolved inorganic carbon (DIC) was processed according to CDIAC's Guide to Best Practices, SOP:2 (Dickson, Sabine, & Christian, 2007). Total alkalinity samples were processed using the spectrophotometric procedures of Yao and Byrne (1998). Dissolved inorganic carbon in the bay ranged between 3500 µMol/L and 2250 µMol/L and, in the Hillsborough River, peaked at 3700 µMol/L just below the Green Swamp. A comparison of measured total alkalinity and calculated alkalinity (obtained using pH and DIC and CO2sys software) demonstrated the presence of substantial organic base concentrations within the bay.

Whitianga Estuary is a bayhead barrier type estuary located on the east of the Coromandel Peninsula, North Island, New Zealand. The catchment has undergone many land-use changes since pre-European settlement. In some areas of the catchment land-use has changed from native forest to grasslands to forestry and back to pasture. These changes in catchment land-use all contribute to increased sedimentation into the estuary. Development of the estuary itself has also occurred in recent times. Much growth has been focussed around the estuary due to Whitianga town-ship having a large boating community, and includes a 170 berth marina and wharf situated at the tidal inlet entrance to the estuary. These, and the extensive canal development engineering works can have substantial impacts on the sedimentation regime, and may modify tidal circulation, flushing, and sediment deposition within the estuary. The principle aim of this research is to assess hydrodynamics and sedimentation of the estuary for future management and development purposes, and also to model different scenarios in order to determine the most cost effective, and least obtrusive design for a proposed boat-ramp and approach channel near the marina. To determine sedimentation rates, sediment cores from four locations were collected to depths of 1 m. Coring locations were chosen based on preliminary model run results, selecting areas that appeared to be long-term sediment sinks of a stable nature. Cores were divided into 10 mm sections and prepared for 210Pb dating and heavy metal analysis, to make an assessment of the vertical sedimentation rates. Recent sedimentation rates were found to be as high as 9 mm/yr post-1950s and past sedimentation rates as high as 30 mm/yr pre-1950s. The use of heavy metal analysis for dating proved difficult as the background levels of the conservative elements used to normalise results varied, making the geochemical analysis approach inappropriate. As bathymetry is one of the most important aspects of modelling, a large amount of surveying was undertaken for this study. LiDAR, singlebeam data, and recent rectified aerial photographs were interpreted for the creation of a bathymetric grid file to be used for hydrodynamic modelling of the estuary. The 3DD numerical model was used to determine tidal flows and current velocities. From this initial hydrodynamic model a particle-tracking model was created to determine sediment transport pathways within the estuary. From the initial 20 m model it was then possible to create a number of nested model grids for the purpose of determining the best practice scenario for the creation of a proposed boat ramp and associated approach channel near the harbour entrance. Hydrodynamic results suggest that residual circulation in Whitianga Estuary is nearly in balance, with a low ebb tidal domination present. Particle tracking results suggest that sediment entrained and carried into and within the estuary will accumulate on the intertidal flats. Sediment transport modelling indicates that the impact of a proposed boat-ramp will result in sedimentation of the dredged approach channel due to reductions in residual and tidal velocities.

Master of Science / Investigations of fluvial and estuarine sediments have indicated stormwater is an important source of heavy metals to Port Jackson estuary and high concentrations of these sedimentary contaminants are a threat to the healthy functioning of the estuarine ecosystem. Stormwater remediation devices have been installed in stormwater channels entering the estuary, however these devices are mainly for removing gross pollutants and are ineffective in removing heavy metals from stormwater. A thorough characterisation of heavy metal inputs and behaviour has been undertaken by sampling, analysing and modelling heavy metals in stormwater entering Port Jackson estuary to provide a rigorous data base for future remediation efforts. A conceptual model of transport and fate of heavy metals in stormwater entering Port Jackson estuary has also been developed to identify heavy metals, subcatchments and flow regimes requiring remediation, and to assist in designing remediation devices for optimum removal of heavy metals from stormwater. Modelling of stormwater using the Model for Urban Stormwater Improvement Conceptualisation (MUSIC) indicated that the average annual discharge of stormwater from the Port Jackson catchment was 215,307 ML. Average annual loadings of arsenic, cadmium, chromium, copper, nickel, lead and zinc in stormwater discharging to Port Jackson estuary were 0.8, 0.5, 1.7, 3.2, 1.1, 3.6 and 17.7 tonnes per year, although comparison to other studies in the catchment suggests these values may be underestimations of actual loadings by 1.3 to 10 times. The proportion of heavy metals discharged under low-flow conditions (<5mm of rainfall in 24 hours), medium-flow conditions (between 5 and 50mm in 24 hours), and high-flow conditions (>50 mm of rainfall in 24 hours) was 6.5%, 62.5% and 31%, respectively. The conceptual model indicates stormwater loadings of copper, lead and zinc pose a risk to the health of riverine and estuarine ecosystems in the catchment and these metals should be targeted for remediation. Stormwater channels which should be prioritised for remediation include the channels entering southern embayments west of Darling Harbour; Duck, Parramatta and Lane Cove Rivers; and the channels and rivers entering Neutral, Long and Sugarloaf Bays. Stormwater loadings of lead are predominantly associated with suspended particulates, whereas loadings of copper and zinc are equally partitioned between dissolved and particulate phases. Stormwater remediation strategies should target both dissolved and particulate phases to ensure effective removal of copper, lead and zinc. Research suggests heavy metals in stormwater discharged to the estuary under high-flow conditions are rapidly exported seaward and bypass the estuary. Preliminary research also suggests that under medium-flow conditions, particulate heavy metals bypass the embayments of Port Jackson and are deposited in the main channel. Once deposited in the main channel, particulate heavy metals are likely to be remobilised and removed from the estuary through multiple phases of resuspension. Although further research is required in this area, this preliminary research suggests remediation should target low-flow conditions. The findings of the current research could be used to identify appropriate remediation strategies for dissolved and particulate phase heavy metals in stormwater discharging to Port Jackson estuary. However, in designing stormwater remediation devices, consideration should also be given to the range of contaminants that may be present in stormwater entering Port Jackson estuary (including suspended solids, nutrients, pesticides and organics).

In situ salinity, turbidity and temperature were measured at discrete depths and water samples for radioanalysis were simultaneously collected in the Columbia River Estuary using a specially designed instrument package. Particulate radioactivity was concentrated by filtration and the dissolved radioactivity by evaporation or ferric oxide bulk precipitation. Radioanalysis was by gamma-ray spectrometry and data reduction by computer. Chromium-51 was mostly dissolved and conservative in brackish water, while zinc-65 was mostly particulate and non-conservative. The intrusion of salt water into the estuary was seen to greatly increase the concentrations of particulate chromium-51, zinc-65 and scandium-46 near the bottom. The fall and rise in estuarine radioactivity levels were followed during an infrequent pause in Hanford reactor operations. Changes in radioactivity levels of up to three orders of magnitude were recorded at Astoria, Oregon, some 380 miles from the reactors. The pause in reactor operations enabled the determination of river flow times from the reactors to Astoria. Flow times of 12 and 19 days were measured for average river discharges of 290,000 and 130,000 c.f.s., respectively. / Graduation date: 1967

Characteristics of minke whale (Balaenoptera acutorostrata) habitat at the head of the Laurentian Channel in the St. Lawrence Estuary, Canada were identified by quantifying environmental and temporal habitat variables and comparing them to the presence or absence of minke whales during the summer of 1996. Identification photographs of minke whales taken during the summers of 1995 and 1996 were used to examine intra-annual and year to year habitat use by individual minke whales. Minke whales were primarily distributed between the 50 m and 100 m bathymetric contours which corresponds to the ridge of the Laurentian Channel. This region is characterized by a steep slope in bottom topography which causes predictable accumulations of euphausiids and capelin (Mal lotus villosus), the principal prey species of minke whales. Tide phase, lunar phase and time of season, all of which cause slight fluctuations in prey abundance did not appear to have a significant influence on minke whale presence or movements. Individual minke whales exhibited site tenacity in returning to a localized area both within a season and in consecutive years. / Graduation date: 1999

Thesis (M.S.)--Oregon State University, 1982. / Typescript (photocopy). Includes bibliographical references (leaves 37-40). Also available on the World Wide Web.

This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and spreads offshore across the ocean surface. This is the Columbia River tidal plume. The fluid velocity of the tidal plume is super-critical (greater than the wavespeed of coastal stratification), which creates a zone of sharp surface velocity convergence at its leading edge, causing a front to form. From early ebb to peak ebb, constant front propagation speed and plume expansion rate are controlled by a linearly increasing volume-flux through the river mouth. Within the plume, turbulence at the plume base is strongly related to the difference between the shear-squared, S², and four times the buoyancy frequency squared, 4N². A parameterization based on the excess shear-squared, S² - 4N², represents Reynolds stress well, indicating that it is driven by Kelvin-Helmholtz instability. During peak ebb of large tides, high volume-flux through the mouth drives high S² - 4N², causing high plume-base stress, which forces significant deceleration of the plume. During smaller tides the volume-flux is smaller, S² - 4N² lower, and the stress too weak to significantly decelerate the plume. During mid-ebb of both small and large ebbs, increasing buoyancy flux from the river mouth raises plume stratification, which suppresses S² - 4N² and stress. As ebb ends, decreasing volume flux and deflection by the Coriolis effect limit plume expansion. This weakens surface velocity convergence, causing the front to diffuse. On longer timescales, plume N² is modulated by changes in river flow; higher river flow causes higher N². During peak ebb of large tides this increase in N² supports higher S², resulting in higher S² - 4N², which causes larger internal stress. These results describe the primary dynamics of the Columbia River tidal plume from front formation to late-ebb, and relate variability in those dynamics to tidal and river-flow forcing. / Graduation date: 2011 / Access restricted to the OSU Community at author's request from Jan. 26, 2011 - Jan. 26, 2013

Modeling the transport and fate of spilled crude oil is important for estimating short and long-term toxicity effects in coastal ecosystems. This research project investigates the partitioning of hydrocarbons from a surface crude oil slick, the resurfacing of chemically dispersed crude oil droplets, the suitability of in-situ field instruments for oil and sediment characterization, and the aggregation and settling of dispersed oil and suspended sediments. An initial laboratory study was conducted to investigate apparent hydrocarbon solubility in petroleum/water systems. Mixing shear and initial crude oil layer thickness were related empirically to oil entrainment rate. A model describing hydrocarbons partitioned in colloidal and soluble phases was consistent with experimental data. A second laboratory study was conducted to investigate the influence of coalescence kinetics on mean droplet size and resurfacing rate of chemically dispersed crude oil droplets. Increased mean shear rates resulted in mean droplet diameters and oil resurfacing rates. A third laboratory study was conducted to compare particle size and fractal dimension measurements obtained using a submersible flow cytometer, an electrozone particle counter, and a light scattering particle sizer. Measured particles included latex beads, crude oil, clay, crude oil-clay aggregates, and crude oil-silica aggregates. Tested instruments gave consistent size measurements for all particle systems, suggesting their suitability for sizing marine particles. To describe the aggregation kinetics of oil-sediment systems, a modified Smoluchowski model based on coalesced sphere (CS) assumptions was developed. Observed collision efficiency values (αOBS) were related to collision efficiency values for single particle type systems (αHOMO) and those for two particle type systems (αHET) using a probabilistic approach. For clay and crude oil, αHOMO values were higher than the αHOMO value for silica. Clay-oil and silica-oil have similar αHET values. Thus, crude oil can significantly increase the aggregation rates of noncohesive sediments such as silica. The CS model above was modified to incorporate sediment fractal geometry. The ability of this modified coalesced fractal sphere (mCFS) model to fit experimental data sets was better than that of a coalesced sphere (CS) model. Because of their reduced settling rates, sediments with lower fractal dimension form more aggregate with dispersed oil.

This study investigates the distributions of trace metals and their controlling mechanisms in the Kaoping coastal zone. Concentrations of most dissolved metals were generally lower in the wet season than in the dry season in the Kaoping Estuary, showing clearly the effects of river discharge rate and water residence time on metal distributions. Dissolved trace metals (Fe, Mn, Zn, Cu, Cd and Pb) behaved non-conservatively with addition in the estuary. Nevertheless, dissolved Pb was apparently removed from the estuary in the wet season. Particulate Al and Fe were derived mainly from continental weathering and their transports through the estuary depend highly on the distribution of total suspended matter (TSM). During the dry season, the occurrence oxygen-deficit condition in the low salinity region and possible pollution from the San-Wei fishery harbor likely determined the distributions and solid-solution partitions of Mn, Zn, Cu, Cd and Pb in the estuary. Distributions of dissolved trace metals in the Kaoping coastal zone were significantly influenced by terrestrial inputs from the Kaoping River. Seasonal variations were attributed largely from the mixing between river water and sea water in the mixing layer and sediment resuspension from canyon bed. The column integrated dissolved and particulate metals were generally higher in the summer season than in other seasons. The difference was especially pronounced in nearshore stations. Concentrations of dissolved Mn, Zn, Cu and Pb increased generally with depth, reflecting the effects of resuspension and lateral transport of bottom sediment. Dissolved Zn and Cu concentrations correlated well with dissolved Mn concentration, but particulate Zn and Cu correlated poorly with particulate Al, implying that distributions of Zn and Cu were controlled by terrestrial inputs and biogeochemical processes in the Kaoping Canyon. Positive and negative correlations are found between dissolved Cd and nutrients (N+N¡Aorthophosphate) and between dissolved Cd and dissolved organic carbon (DOC), respectively, indicating that Cd is a nutrient-type metal and controlled biogeochemically in the Kaoping Canyon. Specific events such as typhoon and earthquake influenced significantly the distributions of trace metals in the Kaoping coastal zone. The integrated suspended-matter and suspended-metal concentrations showed an order magnitude higher during the typhoon season than in the normal summer season. Under the influence of earthquake, the TSM values of the bottom waters were much higher (2-7 folds) during the post- earthquake cruise (Jan/2007) than in the normal season (Jan/2006). Meanwhile, particulate Al, Fe, and Mn can increase up to 2- to 10-folds after earthquake in the bottom layer of canyon. Metal enrichment factor (EF) is an indicator of metal pollution. The EFs show an order magnitude higher in the dry season than in the wet season both in the estuary and canyon. Such seasonal patterns clearly indicate the impacts of local and river inputs on metal distributions in the estuary and canyon.

As the base of the food chain, plankton affect the cycling of nutrients and organic matter within ecosystems and support production at higher trophic levels. The overall goal of this project was to examine how natural water quality fluctuations, such as changes in nutrients, temperature, and salinity, influence estuarine plankton community structure. To achieve this, I examined water quality as well as the diversity and biomass of eukaryotic plankton communities in a subtropical estuary located within the Mission-Aransas National Estuarine Research Reserve. The sampling sites included in this study consisted of three bay (Copano Bay West, Copano Bay East, Aransas Bay) and two river (Mission River Estuary, Aransas River Estuary) estuary sites. Water samples were collected monthly at the five sites from September 2011 to August 2012 and analyzed for a suite of abiotic and biotic variables. Eukaryotic plankton diversity and community structure were evaluated by using the terminal restriction fragment length polymorphism (t-RFLP) method. Although a narrow salinity gradient was present at the sampling sites, seasonal changes in water quality conditions were observed. In the river estuaries, water quality parameters defined three significant temporal periods at the Mission River Estuary site, whereas only one month differed at the Aransas River Estuary site, indicating little seasonal variation. The Copano Bay sites exhibited a seasonal pattern consisting of four periods, marked by a distinct fall (October, November, December) grouping, while Aransas Bay showed a seasonal pattern consisting of three periods, with no fall group. Even though the water quality conditions define different monthly groupings in the bay and river estuary sites, the same parameters – DOC, TDN, and pH – are the strongest drivers of the patterns at all of the sites. Seasonal and spatial distinctions in the Mission-Aransas Estuary eukaryotic plankton community composition were determined using t-RFLP. Frequent shifts in composition were apparent across samples collected at approximately bi-weekly to monthly intervals. There were significant differences (ANOSIM, p < 0.05) in community composition between the Aransas and Mission River Estuary and Aransas Bay sites. Although the overall ANOSIM tests show significance between eukaryotic plankton communities monthly and between the bay water quality periods, none of the pairwise comparisons were significantly different. However, the ANOSIM R-statistic for the monthly pairwise comparisons displays a general increasing trend over time from sampling, further highlighting the dynamic nature of the microbial eukaryotic assemblage within sites. / text