The linear relationship between a conservative element and salinity during mixing of water masses is widely used to study biogeochemistry in estuaries and the oceans. Even though nutrient ratios are widely used to determine the limiting nutrient in aquatic environments, the rules of nutrient ratios change through the mixing of freshwater and seawater are still unstudied. This study provides general rules for nutrient ratios change via mixing. A simple mixing model is developed with the aims to illustrate that nutrient ratio is a nonlinear function of salinity, thus, shift in limiting nutrient over the salinity gradient can be simply a result of river water and seawater mixing, albeit complicated by biological consumption or remineralization. This model explains a natural phenomenon that rivers contain relatively high dissolved inorganic nitrogen (DIN) to soluble reactive phosphorus (SRP) ratios start to decrease the ratios as salinity increases when seawater contains higher SRP:DIN ratios. Although additional sources of P have been implicated as the cause for such change, this change can be a result of riverine water and seawater mixing. Four mixing rules are presented here to explain the factors governing the change in nutrient ratios vs. salinity; thus, answering why in some cases variations in nutrient loading and in other cases mixing triggers changes to seasonal limitation status in some estuaries. Shift in nutrient ratios can be explained by the change in nutrient inventories via mixing. After the P-limited riverine water shifts in N limitation by mixing with N-limited seawater, new production of the estuary in general becomes limited by the amount of N inputs from the riverine water and the seawater. The result may help to explain a current consensus that N and not P riverine loadings lead to eutrophication in estuaries which are influenced by P-limited riverine waters. Further, new production which is generated by N-limited riverine input and N-limited seawater input mainly depends on the amount of N inputs from the riverine water and the seawater.

Heavy-metal pollution is an issue of concern in estuaries such as Biscayne Bay that are heavily influenced by agricultural, urban, and harbor activities. The goals of this study were to provide a state of the bay assessment that can be used to interpret changes that have occurred over the past 60 years in Biscayne Bay, to provide a baseline to compare changes in the ecosystems during and after execution of the Comprehensive Everglades Restorations Plan (CERP), and to determine if benthic foraminiferal assemblages in Biscayne Bay reflect heavy-metal contamination in sediments. Surficial samples were collected at 147 sites throughout the bay. Analyses included geochemical assessment of the mud fraction for 32 chemical parameters, grain-size analysis, and assessment of foraminiferal assemblages at the genus level. Geochemical analyses revealed elevated concentrations of a suite of heavy metals in the sediments of the northern bay, between Miami and Key Biscayne, and the periphery of the southern bay from Black Creek Canal south to Turkey Point. Cluster analysis, multi-dimensional scaling, and multivariate-correlation analyses revealed three distinct foraminiferal assemblages. One assemblage, characteristic of the northern bay, was defined by stress-tolerant taxa including Ammonia, Cribroelphidium, Nonion, and Haynesina, which were present in low abundances. Distribution of this assemblage correlated with the most elevated concentrations of heavy metals. The assemblage that defined the southwestern margin of the bay was dominated by Ammonia and Quinqueloculina. This assemblage is characterized by the lowest diversities and highest abundances, and is likely influenced by both reduced salinity and elevated organic-carbon concentrations.

Emergent morphogenetic designs provide a superior architectural response to programmatic, technical, structural, environmental and spatial requirements that conventional unit based architectural forms are too inflexible to fully address. Architecture has reached an exciting stage in its development, where structures are attempting to behave more like nature, which does not function as a static state, but as a complex grouping of symbiotic processes which are constantly evolving to adapt to environmental changes. Digital fabrication and materials engineering have promoted an explosion in formal architectural typologies. By utilizing these digital tools and enhanced materials to embrace a morphogenetic design strategy, architecture can respond rapidly, through multiple permutations to respond to multiple performance criteria. This approach outlines a design process that generates a typology and through multiple reiterations, changes as the design reacts to new performance criteria being added, or the model not adequately meeting the criteria being tested. The terms used to encompass this new design strategy are emergence, evolutionary optimization or morphogenetic design. This strategy utilizes tools in parallel that have been developed independently by different disciplines, including theoretical mathematics, materials engineering, bio-mimicry, environmental studies and digital technologies. The site is a parcel located on Tampa Bay at the outlet of the Hillsborough River, where the existing unit based Tampa Convention Center will be replaced with the new performance based Convention Center. The research methods will be simulation and modeling research. This method will start with a performance based program, and submit the models to multiple permutations. Each performance criteria will be applied to develop an iterative process that re-informs the shape, design, structure and materials, and can be evaluated at the conclusion of the design process, testing the accuracy of the Thesis.

Growth and development over the past one hundred years has resulted in the construction of causeways and navigational channels in Tampa Bay. Urbanization has lead to bathymetric alterations of the bay, and thus has effectively changed the residual salinity, flow fields, and transport time in Tampa Bay. In this study a numerical ocean model of Tampa Bay was first used to simulate the circulation for 2001-2003 using present day bathymetry. Then, an identical simulation was performed using the bathymetry generated from 1879 depth soundings. The residual (30-day time average) circulation fields and salinity, along with transport times was intercompared for different freshwater inflow conditions to investigate the impacts of these physical alteration. The salinity for the "present" simulation is about 3 psu higher than the "1879" simulation in the areas of upper Middle Tampa Bay, Lower Hillsborough Bay and Old Tampa Bay, a result of a stronger axial pressure gradient associated with the deeper more extensive channels. Velocities are up to 10 cm/s higher in the "present" run than in the "1879" simulation in the areas where water must converge and diverge through the narrow openings of the bridges/causeways. Transport time is short (~10 days) during strong residual circulation, and long (~90 days) during weak residual circulation. Bridges and causeways are associated with longer transport times (~90 days), except in the area North of the Courtney Campbell Causeway. The navigational channel is associated with long transport times during dry periods and short transport time during wet periods.

A detailed study of modern washover fan (fan) morphologies will clarify common fan geometries, lead to a better model for a “typical” fan, identify the preservation potential and probable geometries of fan facies in subsurface datasets and outcrops, and ultimately improve hydrocarbon recovery in barrier island reservoir systems. This study uses satellite imagery to conduct a spatial analysis of 118 modern fans to quantify geomorphologic attributes of fans. A new classification scheme for fans is proposed that refines the current fan model, dividing fans into channelized and non-channelized fans. Channelized fans are subdivided according to the location of primary deposition: barrier depo-center or lagoonal depo-center. Non-channelized fans are subdivided based on morphology: dissipative, lobate, or apron-sourced. Quantitative cross-plots of morphologic relationships are analyzed to define trends in fan morphologies. The most common type of fan encountered in our study is a non-channelized, line-sourced, lobate washover fan with an area of less than 1 km2 that is fully contained on a barrier and exhibits no subaqueous deposition in back-barrier waters. The Lower Cretaceous McMurray Formation is the primary reservoir of the Athabasca Oil Sands in Alberta, Canada. The upper McMurray is commonly interpreted as deposits of embayed coastal systems. Our location is in an under-studied area located 80 km northwest of Fort McMurray. Lateral and vertical facies changes, sedimentary structures, key surfaces, trace fossils, and bitumen saturation were documented in eight cores located along a 20 km transect situated paleo-landward of a Devonian paleo-high acting as a bedrock-barrier. Our data indicate that a flood tidal delta complex prograded landward into a back-barrier embayment through the stable, bedrock-controlled inlet. This system overlies middle McMurray fluvial sands and Devonian basement and was transgressed by marine waters prior to deposition of the overlying Wabiskaw Formation. Flood tidal delta sandbodies are bitumen saturated and therefore make good reservoirs; however, heavily bioturbated tidal flats can act as a barrier to flow where they encase flood tidal deltas, as encased sands were devoid of bitumen. This complex coastal paleogeography produced back-barrier deposits that contain a slightly more diverse, marine trace fossil assemblage than might otherwise be expected. / text

A numerical circulation model of Tampa Bay, Florida is used to simulate the flow field and tidal residual circulation for 2001-2004. This model is used to investigate the effects of extreme events on the residual circulation of the bay. The three extreme events that are used in this study are: Hurricane Frances, Hurricane Jeanne, and an extreme winter frontal passage that occurred on December 26, 2004. Each extreme event was divided into phases that were chosen by wind peaks and times of velocity inflow and outflow. There were three phases to the hydrodynamics effect of Frances on Tampa Bay. Hurricane Jeanne and the winter frontal passage each had two phases. An important difference between the three extreme events is the duration of each; Hurricane Frances lasted approximately two and a half days, Hurricane Jeanne affected the bay area for about twenty-four hours, and the extratropical storm passed within 16 hours. Winds were six standard deviations higher than the 2004 mean (4.06 m s-1) during Hurricane Frances, and seven standard deviations higher during both Hurricane Jeanne and the extratropical storm. Water levels reached four standard deviations during Hurricane Frances and the extratropical storm, and two standard deviations during Hurricane Jeanne. The difference between these results is due to the timing of each event with the tides, whether it was in or out of phase with the tides. During phase 2 of Hurricane Frances there was a total volume inflow of m3, for an increase of 60% in bay volume. There was a total volume outflow during phase 3 of m3, a 28% decrease. During Hurricane Jeanne there was a total volume inflow of m3 (30% increase) and total volume outflow of m3 (14% decrease). The extratropical storm showed a total volume inflow of m3 (29% increase) and a total volume outflow of m3 (31% decrease). Though the increase and decrease of volume for each event was different, they all had the same affect on the bay, causing changes in the residual circulation over time scales of these extreme events.

The Tay estuary is situated on the east coast of Scotland. The estuary is dominated by sediment biotopes, including mudflats which support sparse beds of two nationally scarce seagrass species, Zostera marina var. angustfolia (Hornem.) and Z. noltii (Hornem.). Seagrasses have been described as ecosystem engineers, shaping their sediment environment, and this may increase sediment deposition and stability. In this thesis the ecosystem engineering characteristics of seagrass habitats are explored. In 2008, the distribution of Zostera spp. in the Tay estuary was surveyed and mapped for the first time. Sediments within beds of Z. marina and Z. noltii were compared to investigate the influence of seagrasses on sediment characteristics. To explore the role of seagrass in sediment deposition and erosion, and coastal stability, sediment depth measurements were made in patches of Z. noltii, Z. marina and bare sediment over one year. The role of the root/rhizome system on sediment retention over winter was also considered. Sediment deposition in Z. noltii beds, and the influence of the plants on near-bed flow dynamics was further explored in the laboratory, using an 8 m seawater flume. In the field the retention of particles over 2 and 14 tides was measured, and the results of this experiment led to a study of the influence of leaf and sediment biofilms on particle retention, using the novel method of magnetic particle induction (MagPI). The efficacy of artificial seagrass beds and Z. noltii transplantation as habitat restoration techniques were compared over one year. During the trial, sediment deposition and changes in sediment characteristics were determined, and the protection given to saltmarsh cliffs fringing the study plots was assessed. Mechanisms underlying the results are suggested and the findings discussed. This study provides an insight into the ecology of seagrass in the Tay estuary and its role as an ecosystem manager. It may offer valuable data which could be utilised for future conservation policies, habitat restoration schemes and management planning of the area.

The temporal variation of nematode communities in eight mouth stations of the Mekong River system was investigated in order to compare the change between the dry and the wet season. The nematode data was analysed by multivariate techniques such as SIMPROF, MDS, ANOSIM and SIMPER in the software PRIMER v.6 – PERMANOVA. Our results showed that average dissimi-larity between seasons of the nematode communities in each station was high. Seasonal factor did not affect strongly their distribution pattern. Dominant genera Desmodora and Oncholaimellus usually occurred in the sand stations and Parodontophora and Halalaimus were characteristic for the silty group in both seasons. The spatial variations in this estuarine area have an influence that is larger than seasonal factors. / Sự phân bố theo thời gian của quần xã tuyến trùng sống tự do vùng cửa sông Mekong được nghiên cứu nhằm đánh giá sự khác biệt của chúng trong mùa mưa và mùa khô. Dữ liệu của tuyến trùng được xử lý và phân tích đa biến như SIMPROF, MDS, ANOSIM và SIMPER bằng phần mềm PRIMER v.6 – PERMANOVA. Kết quả nghiên cứu cho thấy sự khác biệt theo mùa trong quần xã tuyến trùng tại mỗi điểm là khá lớn nhưng yếu tố mùa không ảnh hưởng gì tới mô hình phân bố của chúng. Một số giống ưu thế trong nền đáy cát như Desmodora and Oncholaimellus trong khi đó Parodontophora và Halalaimus thích nghi nền bùn sét phù sa vẫn hiễn diện trong cả 2 mùa. Kết quả nghiên cứu cũng cho thấy sự biến động trong không gian ở đây lớn hơn sự biến động về mùa vụ.

No description available.

The behaviour of Surf Scoters (Melanitta perspicillata ) was studied on staging grounds in spring of 2006 and compared to behaviour on moulting grounds later that summer. Moulting Surf Scoters have a distinct activity pattern in comparison to those on spring staging grounds. During moult, foraging occurs mainly in the morning and evening, whereas during the spring a similar proportion of birds foraged at all periods of the day. Birds having recently initiated moult foraged significantly less that on staging grounds. However, as moult progressed, this discrepancy disappeared. / In addition, we tracked the movements of flightless Surf Scoters using satellite telemetry during the 2006 wing-moult period. Despite their reduced mobility, Surf Scoters are able to swim long distances while flightless. However, the majority of their activities are carried out within small core areas. This study also indicates that satellite telemetry can be used effectively to track the daily movements of wildlife.