There is an increasing need for renewable energy sources to replace fossils fuels which accumulate harmful byproducts in the environment. Biodiesel emits less gaseous pollutants than diesel. There are various sources for biodiesel but they are unable to meet the existing demands for fuel. Microalgae are a promising source for biodiesel because of its relatively faster growth rate, availability, and lipid content. Microalgae (JC and BT) growing in local water bodies were collected, selected on section media containing antibiotics, and used for characterizations. Experiments were conducted to study and evaluate the optimum growing conditions. Results show that both JC and BT attain maximum growth with shaking and additional aeration compared to control microalgae Dunaliella salina, Nannochlorposis oculata which do not require additional aeration for optimal growth. Lipid extraction results suggest that JC (9.7%) and BT (4.1%) have slightly higher lipid content compared to control algae e.g. Chlamydomonas reinhardtii (3.1%).

High latitude mountain environments are experiencing disproportionately adverse effects in a currently changing climate. The Gulf of Alaska (GoA) region is an exemplar of this. Dramatic shifts are occurring in the region’s freshwater reservoirs as glaciers retreat more with each passing year. Research in the region places much focus on observing and predicting climate driven shifts in glacier mass balance, surface discharge, and associated nutrient fluxes to the ocean. On the other hand, coastal groundwater discharge (CGD) is given very little attention. Global and near-global estimates of CGD indicate variable results spanning an order of magnitude. Focusing on regionally specific processes may provide more reliable estimates of CGD and allow isolation of CGD hotspots. This is of particular importance in the GoA region where complex topography, geology, and climate are coupled with recharge derived from rain, snow, and ice. I estimate CGD to the GoA with a water balance that integrates high temporal and spatial resolution recharge inputs and distinguishes between high conductivity surficial deposit and bedrock catchments. I find that CGD contributes nearly 3% of the total freshwater flux to the GoA, equivalent to a mean annual flux of 20.8 km3, and that CGD has been increasing by 0.5%/year over the past 4 decades. Although freshwater discharge to the GOA is well-constrained, the importance of fresh CGD to the GoA has, thus far, been overlooked.

<p> This report is the only detailed study concerning the fresh water cobble beaches of the Georgian Bay Islands. It includes extensive studies on the morphological characteristics, especially the platform development and profile configuration, and the sedimentary provenance of the cobbles. </p> <p> It was found that the platform configuration (step topography) acts as a substrate control for the cobble beaches. The presence of two cobble generations, angular and well-rounded, indicate that t he shore platform is the source for these cobble beaches. </p> <p> The roundness values of these cobble generations depends on t heir mode of transport. Evidence indicates that longshore movement of cobbles increases their roundness values, but their angular shape i s indicative of their lack of transport. </p> <p> Very little proof was found within this study to correlate relict cobble beaches with any specific stage of the Lake Huron Basin, although it was possible to generalize and state that the relict cobble beaches were generated by high-energy wave events during the transition from the Algoma stage to Lake Huron. </p> <p> Clast analysis determines the relationship between the length of the wave fetch and its related energy environment. It was found that high-energy coastal environments have oblate cobbles with a high roundness and low sphericity. In each case, the samples were associated with a large fetch. Those cobbles of a low-energy coastal environment have a high sphericity, low roundness, and are associated with smaller fetches. </p> <p> The steepness of the beach profile results from the increase in wave height, generated by an increase in shallowness. It also depends upon the volume of backwash. The backwash is reduced by the increased percolation rates through the cobbles, thus reducing the combing down effect of the backwash. </p> <p> This study also provides a discussion on the minor morphological features such as sinkholes and imbrication. </p> / Thesis / Bachelor of Arts (BA)

The Atlantic Meridional Overturning Circulation (AMOC) is thought to exert considerable influence over the climate via heat redistribution and carbon storage. Its repeated variations along with the regional and global climate during the last glacial cycle suggest that the state of the AMOC may be roughly divided into “warm,” “cold,” and “off” modes. The three modes correspond to the vigorous deepwater formation in the subpolar North Atlantic, a reduced deepwater formation, and the widespread disruption of the AMOC, respectively. Questions remain about the cause and response of AMOC perturbations in each of the three modes.Reconstruction of the burial flux of ice-rafted debris can resolve questions about the timing and rates of ice sheet calving, which may have been responsible for the “off” mode of the AMOC, given the association of freshwater forcing with AMOC strength. The first chapter quantified the flux of ice-rafted debris in a pair of cores collected from sites in the western North Atlantic. The results show higher ice-rafted debris flux during all Heinrich events and that the western North Atlantic fluxes were higher than the east. The data demonstrate that the Laurentide Ice Sheet played a role in all Heinrich events. A catastrophic last interglacial Laurentide outburst (LILO) event some 125,000 years ago (125 ka) may have contributed to abrupt climate change during the Eemian, when the AMOC was in the “warm” mode. The LILO event was previously proposed to be an analog of the Holocene 8.2 ka event. The second chapter investigated the age and chemical compositions of a layer of red sediments deposited across much of the Northwest Atlantic at 125 ka. The results provide strong support for the occurrence of the LILO event that was analogous to the 8.2 ka event in provenance, timing, and delivery. Little is known about the zonal (east/west) characteristics of the AMOC when in the “cold” mode during the Last Glacial Maximum. Authigenic uranium preserved in sediments is a sensitive redox tracer and can shed light on bottom water oxygen, carbon storage, and water mass distributions. In the third chapter, new and published authigenic uranium data were used to reconstruct deep ocean oxygenation. The compilation shows that lower-than-Holocene oxygen and correspondingly greater respired carbon storage were persistent features of the LGM in the deep North Atlantic. The eastern basin was substantially less well oxygenated than the west. A farther advance and greater infilling in the east of deep waters originating from the Southern Ocean may have caused the zonal difference. Alternatively, deep waters originating from the subpolar North Atlantic may have increased in their residence time in the eastern transect. Questions remain about the flux of freshwater necessary to induce the AMOC to enter the “off” mode. Existing estimates do not agree on the freshwater fluxes associated with Heinrich events. The fourth chapter uses compiled 230Thxs-based mass fluxes in the North Atlantic during the last glacial period to calculate the surge mass fluxes as a measure of the rate of ice-rafted debris deposition. The surge mass fluxes were then converted into freshwater fluxes. Freshwater fluxes for an arbitrarily defined 2000-year period and total freshwater volumes between 20° and 70° N were as high as 0.11 Sv and 6.9 × 1015 m³ during Heinrich event 4 and as low as 0.0012 Sv and 7.6 × 1013 m³ during Heinrich event 3. The relatively low freshwater fluxes we reconstructed for Heinrich events might suggest potentially a high sensitivity of the Atlantic Meridional Overturning Circulation to freshwater perturbations, although the freshwater volumes are in line with previous reconstructions. Our project represents the first time an attempt made to reconstruct the freshwater fluxes and volumes during all Heinrich events of the last glacial period.

River herring, collectively alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis), have experienced substantial population declines over the past five decades due in large part to overfishing, combined with other sources of mortality, and disrupted access to critical freshwater spawning habitats. Anadromous river herring populations are currently assessed by counting adults in rivers during upstream spawning migrations, but no field-based assessment methods exist for estimating juvenile densities in freshwater nursery habitats. Counts of 4-year-old migrating adults are variable and prevent understanding about how mortality acts on different life stages prior to returning to spawn (e.g., juveniles and immature adults in lakes, rivers, estuaries, and oceans). This in turn makes it challenging to infer a link between adult counts and juvenile recruitment and to develop effective management policy. I used a pelagic purse seine to investigate juvenile river herring densities, growth, and mortality across 16 New England lakes. First, I evaluated the effectiveness and sampling precision of a pelagic purse seine for capturing juvenile river herring in lakes, since this sampling gear has not been systematically tested. Sampling at night in June or July resulted in highest catches. Precision, as measured by the coefficient of variation, was lowest in July (0.23) compared to June (0.32), August (0.38), and September (0.61). Simulation results indicated that the effort required to produce precise density estimates is largely dependent on lake size with small lakes (<50 >ha) requiring up to 10 purse seine hauls and large lakes (>50 ha) requiring 15–20 hauls. These results suggested that juvenile recruitment densities can be effectively measured using a purse seine at night in June or July with 10–20 hauls. Using juvenile fishes captured during purse seining in June–September 2015, I calculated growth and mortality rates from sagittal otoliths. Density, growth, and mortality were highly variable among lakes, and mixed-effects regression models explained 11%–76% of the variance in these estimates. Juvenile densities ranged over an order of magnitude and were inversely related to dissolved organic carbon. Juvenile growth rates were higher in productive systems (i.e., low secchi depth, high nutrients) and were strongly density-dependent, leading to much larger fish at age in productive lakes with low densities of river herring compared to high density lakes. Water temperature explained 56%–85% of the variation in juvenile growth rates during the first 30 days of life. Mortality was positively related to total phosphorous levels and inversely related to hatch date, with earlier hatching cohorts experiencing higher mortality. These results indicate the importance of water quality and juvenile densities in nursery habitats for determining juvenile growth and survival. This study encourages future assessments of juvenile river herring in freshwater and contributes to an understanding of factors explaining juvenile recruitment that can guide more effective and comprehensive management of river herring.

The study examines the management of Legionella in the Swedish merchant fleet by mapping existing methods and proposing measures. Through a literature review and interviews with shipping company employees and industry experts, three research questions are analyzed: What are the most common preventive measures on board, common sanitation methods and how can these be made more efficient when it comes to eliminate Legionella. The results point to common methods such as UV irradiation and hot water flushing. The discussion highlights the reliability of the method and the industry's need for increased knowledge and clearer guidelines. The conclusions emphasize the need for measures such as Legionella filters, regular testing of fresh water, and long-term solutions focusing on the source of the problem, such as risk assessments. Education, awareness, and preventive measures are crucial for combating this hidden and costly problem in modern shipping.

Yes / In this research, the effect of operating parameters on the fresh water production cost of hybrid Multi Effect Distillation (MED) and Reverse Osmosis (RO) system is investigated. To achieve this, an earlier comprehensive model developed by the authors for MED + RO system is combined with two full-scale cost models of MED and RO processes collected from the literature. Using the economic model, the variation of the overall fresh water cost with respect to some operating conditions, namely steam temperature and steam flow rate for the MED process and inlet pressure and flow rate for the RO process, is accurately investigated. Then, the hybrid process model is incorporated into a single-objective non-linear optimisation framework to minimise the fresh water cost by finding the optimal values of the above operating conditions. The optimisation results confirm the economic feasibility of the proposed hybrid seawater desalination plant.

The purpose of this investigation is to attempt to relate the distribution and periodicity of the plankton to the variations in the biological, chemical, and physical factors.

The purpose of this investigation was to isolate and grow algae common to the southwest in unialgal culture; to either sustain or grow one of the principal bloom-causing organisms, with emphasis on Microcystis aeruginosa; to isolate and culture actinomycetes from the same waters from which the algae were obtained; and to inoculate these algae with actinomycetes and determine their effects through development and deterioration.

The purpose of this investigation is to determine the suspended organic matter and the total phosphorus in the waters of Lake Dallas and to evaluate these findings. Since organic matter floating in lakes is largely composed of minute plants, animals, and detritus derived from animals and plants, the fertilizing effect of phosphorus must be considered as an integral part of this problem.