Dissertations / Theses on the topic 'Marine environment'
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Gebbels, Susan. "Promoting citizenship and environmental learning in the marine environment." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2298.
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This thesis addresses the need to involve all members of society in marine environmental education, policy-making and stakeholder processes. Several strategies are considered. Firstly, marine environmental citizenship and the concept of joint responsibility as a way of enabling people to contribute meaningfully to marine environmental management processes. This incorporates the implementation of programmes that enable adults to participate in local environmental projects and the importance of using skilled volunteers in wildlife recording programmes. Chapter two outlines ‘A Citizens’ Day’ between school pupils and environmentalists that enables participants to take part in debates and environmental planning in real life situations. The thesis examines the effects of links between universities, industries and schools were pupils surveyed a coastal area and made 15 recommendations for its sustainable management which were implemented by industry employees. Intergenerational learning as a means of encouraging transfer of knowledge between generations was tested in depth during one study. The methods proved effective, the majority of the adults in the project claimed that their knowledge of their areas maritime heritage had increased significantly. ‘The Tale of the Herring’ project looked at the concept of sense of place education as a tool for promoting environmental citizenship and connecting young people to their marine environment. The results of the study concluded that this approach did encourage a feeling of belonging and a sense of responsibly for one’s local environs. Global marine citizenship was assessed through International Schools Partnership in Ghana and the UK. Schools carried out independent surveys of local coastal habitats and made recommendations to managers. Despite many differences in their lives, pupils’ recommendations had many similarities. Innovative methods of giving children who have Special Education Needs a voice in marine environmental citizenry were also investigated. The focus had special emphasis on fieldwork, enquiry-based and cross-curricula approaches to learning. Pupils’ believed that their work motivated their interest in science and gave them a sense of pride in their work. Finally the thesis explored the potential use of the creative arts as an effective means of communicating marine environmental messages.
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Hamidian, Amir Hossein, and n/a. "Cadmium in the marine environment." University of Otago. Department of Chemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20090728.100026.
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Cadmium in the ocean has a nutrient-like cycling pattern: with biological uptake at the surface, subsequent sinking in particulate form and then regeneration as dissolved species in deeper waters. Many measurements have been made over time of the ratio of the concentrations of dissolved Cd to those of PO₄ (Cd/PO₄) in the world ocean and this has become one of the best relationships documented between a trace metal and a nutrient. Combined with the measurements of the Cd/Ca ratio in foraminifera, the Cd/PO₄ ratio has been used to reconstruct the oceanographic circulation patterns that existed during past glacial periods and hence provides information on past climate changes.
In the present study Cd/PO₄ ratios of the Southern Indian Ocean in surface and deep waters were investigated. The slopes of the relationships between Cd and PO₄ concentrations in waters of this region are high compared to the global correlations, and lie between those reported for other parts of the Southern Ocean and the Pacific Ocean. In surface waters of the Southern Indian Ocean, Cd/PO₄ ratios decrease from regions exhibiting high nutrient-low chlorophyll (HNLC) characteristic in the south to oligotrophic waters further north. It is also found that particulate Cd plays an important role in regulating the high Cd/PO₄ ratios reported in waters south of the Polar Front.
Very low Cd/PO₄ ratios were measured in waters associated with the Subtropical Front southeast of New Zealand compared to other Southern Ocean and global oceanic waters. Seasonal variations in the Cd/PO₄ ratios measured for these waters strongly suggest they are associated with a significant biological uptake of dissolved Cd particularly during the phytoplankton growth season in summer.
Dissolved Fe concentrations in the Southern Indian Ocean and seasonal variations of Fe in waters off the Otago Coast (southeast of New Zealand) suggest that Fe may stimulate phytoplankton growth and this might result in lower Cd/PO₄ ratios in surface waters through enhanced Cd uptake relative to PO₄ by the phytoplankton. However there is no distinct relationship between dissolved Fe concentrations and the dissolved Cd/PO₄ ratios measured in these surface waters. This finding is in disagreement with the recent 2006 hypothesis put forward by J.T. Cullen, which proposed that waters exhibiting low dissolved Cd/PO₄ ratios were associated with the HNLC regions. From a consideration of the potential Zn concentrations calculated from Si concentration measurements reported for these waters, it would appear that Zn may play a more important role than Fe in regulating Cd/PO₄ ratios in these waters.
Measurements of dissolved and total Cd concentrations relative to those of PO₄ were also undertaken in the Otago Harbour and immediate surrounding coastal waters. These exhibited higher Cd concentrations and higher Cd/PO₄ ratios than open ocean waters further off the Otago Coast. The particulate Cd concentrations showed a negative correlation with Cd concentrations measured in cockle species (Austrovenus stuchburyi) collected in the harbour, suggesting that particulate Cd is not the source of Cd measured in the tissue of this species.
The concentrations of Cd and other trace metals were also measured in samples of green mussel (Perna canaliculus), ribbed mussel (Aulacomya atra maoriana) and oyster (Saccostrea cucullata) collected from Otago Harbour and possible correlations explored between these concentrations and other parameters such as the shellfish condition indices and environmental gradients in the harbour.
In summary, measurements of dissolved and particulate Cd concentrations in the water column can provide unique information on a number of processes occurring in the global marine environment.
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Harvey, J. S. "Genotoxins in the marine environment." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637236.
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This thesis describes the development and optimisation of the 32P-postlabelling assay and the Restriction Site Mutation (RSM) assay for the detection of DNA adducts and mutations, respectively, in the marine bioindicator species, Mytilus spp. The standard approach to adduct analysis was modified, to eliminate various artefacts connected directly to the 32P-postlabelling procedure and to the method of DNA isolation. Initial studies demonstrated that specimens of Mytilus spp. from several locations possessed adducts. The exact origin of these adducts could not be accurately determined due to the multitude of possible etiologies. The capacity of the species to form genotoxin induced adducts was confirmed by a series of acute in vitro and in vivo laboratory exposures to 2-aminoanthracene, 2-aminogluorene, 2-acetylaminofluorene, benzo[a]pyrene and 4-nitroquinoline 1-oxide. These studies indicated that hepatopancreas adducts, in Mytilus spp., could be used as dosimeters of acute exposures to selected genotoxins. Further studies indicated that there was a delay in the maximum levels of adduct formation in Mytilus spp., following acute genotoxin exposure and that the species possessed the capacity to repair bulky genotoxin induced adducts. The persistence of these genotoxin induced adducts suggested however, that they could provide an indication of long-term exposure to selected genotoxic compounds. The standard 32P-postlabelling assay was inappropriate for the detection of adducts induced in Mytilus spp. following chronic exposures to either single, or complex mixtures, of genotoxins. In certain circumstances, the presence of pre-existing 'background' adducts compromised the analysis of genotoxin induced adducts. The application of the RSM assay was limited due to the lack of suitable DNA target sequences in Mytilus spp. The optimisation of available sequences together with recent advances in the assay's sensitivity and reliability, suggests that the assay has the potential for the analysis of the long-term effects of genotoxin exposure in Mytilus spp.
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Sousa, Sónia de Fátima Félix Ferreira de. "Emergent viruses in the marine environment." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7546.
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Mestrado em MicrobiologiaThe enteric viruses generally are transmitted by the fecal-oral route and constitute a threat for the public health. They can be transmitted from the marine environment through the ingestion of recreational waters or through the consumption of bivalves, being its transmission from the marine environment considered many times emergent. Water virology started around half a century ago, with scientists attempting to detect poliovirus in water samples. Since that time, other enteric viruses were found to be responsible for outbreaks of gastroenteritis and hepatitis. The majority of the enteric viruses that have a sea waterborne transmission belong to the families Caliciviridae, Adenoviridae, Picornaviridae and Reoviridae. This work has as objectives to evaluate the importance of the transmission of enteric viruses for the marine environment, reviewing the factors that affect its survival in this environment and enumerating the cases of emergent transmission. Many factors could influence their surveillance in marine environments, such as water temperature, UV radiation, pH, salinity, raining, and adsorption to sediments among others. The number of outbreaks of viral gastroenteritis has increased in the developed countries of Europe and North America. Caliciviridae family and hepatitis A viruses of Picornaviridae family are responsible for the majority of the waterborne gastroenteritis outbreaks, due to the consumption of contaminated raw bivalves. The majority of emergent outbreaks are linked to imported contaminated bivalves from endemic areas, with bad sanitary conditions. Some emergent cases are linked to the occurrence of new, more virulent, strains of existent viruses, like norovirus strains, or through waterborne transmission that was previously unknown for this type of viruses (e.g. polyomaviruses and some enteroviruses).
Os vírus entéricos são geralmente transmitidos pela via fecal-oral e constituem uma ameaça para a saúde pública. Podem ser transmitidos a partir do ambiente marinho através da ingestão de águas de recreio ou do consumo de bivalves, sendo a sua transmissão a partir do ambiente marinho considerada muitas vezes emergente. A virologia aquática começou há meio século atrás, com a tentativa de alguns cientistas em detectar poliovírus em amostras de água. Desde essa altura, vários vírus entéricos têm sido associados a outros surtos de gastroenterite e hepatite. A maioria dos vírus entéricos, transmitidos a partir do ambiente marinho pertence às famílias Caliciviridae, Adenoviridae, Picornaviridae e Reoviridae. Este trabalho tem como objectivos avaliar a importância da transmissão de vírus entéricos pelo ambiente marinho, revendo os factores que afectam a sua sobrevivência neste ambiente e enumerando os casos de transmissão emergente. São vários os factores que podem condicionar a sobrevivência destes vírus no ambiente marinho, tais como, a temperatura da água, a radiação UV, o pH, a salinidade, a pluviosidade e a adsorção a sedimentos. O número de surtos de gastroenterite de natureza viral tem vindo assim a aumentar nos países desenvolvidos da Europa e da América do Norte. A família Caliciviridae e o vírus da hepatite A da família Picornaviridae são responsáveis pela maioria dos surtos, causando gastroenterites devidas, principalmente, ao consumo de bivalves contaminados e mal cozinhados. A maioria dos casos emergentes está relacionada com a importação de bivalves contaminados de zonas endémicas, onde as condições de higiene são deficitárias. Alguns dos casos emergentes estão relacionados com a ocorrência de novas estirpes de vírus, mais virulentas, como é o caso das estirpes de norovírus, ou através da transmissão por via marinha, anteriormente desconhecida para alguns grupos de vírus (ex. polyomavirus e alguns enterovirus).
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Puente, Isabel. "Sources of Coliphage to the Marine Environment." NSUWorks, 1991. http://nsuworks.nova.edu/occ_stuetd/361.
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Coliphages may be an alternative to bacterial indicators of sewage pollution in sea water. However, non-human sources of coliphage to the marine environment have not been investigated. A study was conducted in Southeastern Florida to determine how E. coli C (ATCC 13706) bacteriophages of non-human origin could interfere with the coliphage indicator system in the monitoring of human fecal pollution in sea water. Coliphages were detected, in variable numbers, in 12.5%, 80%, and 33.3% of human, seagull (Larus delawarensis), and pelican (Pelicanus occidentalis carolinensis) fecal samples, respectively, as well as in 100% of raw sewage samples. No coliphage was detected in feces of dolphin (Tursiops truncatus) and sea lion (Zalophus californianus). Single fecal samples of cormorant (Phalacrocorax auritus floridanus) and royal tern (Thalasseus maximus maximus) also contained coliphage. The coliphage content per gram of dry weight of raw sewage was significantly (α = 0.00007) higher than that of all the other fecal samples. Even though coliphage titers in the animal feces are lower than in raw sewage, in restricted geographical areas (i.e. marinas), non-human animal sources may still be important.
Three time series analyses were performed to investigate the inconsistent detection of coliphage in human feces. Coliphage was present in only 3 out of 7 fresh human stool samples. However, coliphages appeared after several days of aging of the samples in a dilution of sterile phosphate buffered water. It is hypothesized that lysogenic bacteria in human feces release coliphage through spontaneous induction and physico-chemical conditions outside the human intestine may trigger this induction.
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Goodman, Michael David. "Polynuclear aromatic hydrocarbons in the marine environment." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1611.
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Broadgate, Wendy J. "Non-methane hydrocarbons in the marine environment." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296358.
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Cunningham, Andrew Donald. "Monte Carlo simulation in the marine environment." Thesis, Liverpool John Moores University, 2011. http://researchonline.ljmu.ac.uk/6001/.
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Mendes, Carlos Miguel da Cruz. "Importance of lisogeny in the marine environment." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/883.
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Mestrado em MicrobiologiaUm dos papéis mais importantes dos vírus em sistemas aquáticos é a sua capacidade de agir como vectores para a transferência de genes, sendo a lisogenia o mecanismo-chave neste processo. A lisogenia pode ajudar os vírus a sobreviver a períodos de reduzida abundância de hospedeiro e / ou escassez de nutrientes, contribuindo também para o aumento de “fitness” do hospedeiro. Devido à sua localização, na interface entre a hidrosfera e a atmosfera, a microcamada superficial está exposto a elevada intensidades de radiação solar, elevadas concentrações de poluentes e metais pesados e flutuações de temperatura e salinidade. Representa, portanto, um ambiente de stress para os microrganismos, pelo que estes poderão ter desenvolvido estratégias adaptativas à sobrevivência neste microhabitat, nomeadamente a lisogenia. Por outro lado, sendo a radiação UV um importante indutor da lisogenia, a sua elevada intensidade na microcamada poderá resultar numa maior frequência de células lisogénicas neste compartimento. O objectivo deste trabalho foi o estudo da importância da lisogenia na microcamada superficial e água subsuperficial na zona marinha e salobra da Ria de Aveiro (Portugal), tendo a fracção de células lisogénicas sido determinada após indução dos profagos com mitomicina C. Neste estudo também foi quantificado o número de bactérias que são contados como vírus quando a abundância viral é determinada por microscopia de epifluorescência. A percentagem de células lisogénicas na microcamada superficial da zona marinha variou entre 1,2% e 3,1% e na água subsuperficial entre 1,0% e 5,3%. Na zona salobra, a proporção de células lisogenicas na SML variou entre 0,9% e 6,0% e na coluna de água entre 1,0% e 4,7%. A fracção de bactérias lisogénicas foi semelhante na microcamada superficial e na água subjacente. Não foi observado um perfil de variação sazonal nítido para a lisogenia, mas a fracção de bactérias lisogénicas foi maior, em ambos os compartimentos, quando as condições ambientais foram mais adversas. Os perfis de DGGE mostraram que alguns grupos de bactérias desapareceram após a indução da lisogenia, mas outros grupos de bactérias, não observados no controle, apareceram após a adição da mitomicina. Na zona marinha do sistema estuarino da Ria de Aveiro 27% das partículas contadas como vírus são bactérias, mas na zona salobra apenas 14% dessas partículas são bactérias. Embora a ocorrência de lisogenia no sistema estuarino da Ria de Aveiro não seja muito alta, a variação sazonal da fracção de bactérias lisogénicas sugere que a lisogenia pode ser influenciada por variações de temperatura, salinidade ou intensidade de radiação UV. Quando a microscopia de epifluorescência, é usado para contar partículas virais, a abundância viral pode ser sobrestimada, nomeadamente na área marinha.
Acting as gene transfer vectors constitutes one of the main roles played by viruses in aquatic systems, being lisogeny a key mechanism in this process. Lisogeny can help viruses withstand low host abundance periods and/or nutrient limitation, potentially contributing to increased fitness of the host as well. Due to its location, at the air-water interface, the surface microlayer (SML) is exposed to high intensities of solar radiation, enhanced concentrations of pollutants and heavy metals and strong temperature and salinity fluctuations. Therefore, it represents a stressful environment for microorganisms, which might have developed adaptative strategies for survival at this interface, including the presence of prophages. On the other hand, as UV radiation is an important lisogeny inducer, intense UV levels at this layer might result in increased lisogenic cell frequency in the SML. The aim of this work was to study the role of lisogeny at the SML and underlying waters (UW) of the marine and brackish water sections of Ria de Aveiro (Portugal), using the mitomycin C method to induce prophage. In this study was also quantified the number of bacteria that are counted as viruses when viral abundance is determined by epifluorescence microscopy. The proportion of lisogenic bacteria in the marine zone ranged from 1.2% to 3.1% at the SML and from 1.0% e 5.3% in the UW. At the brackish water site, the fraction of lisogenic bacteria ranged from 0.9% to 6.0% at the SML and 1.0% to 4.7% at the UW. The fraction of lisogenic bacteria was similar in SML and in UW. It was not observed a clear pattern of seasonal variation of lisogenic bacteria, but the high values of lisogeny were observed, for both compartments, when the environmental conditions were more adverse. The DGGE profiles show that some groups of bacteria disappeared after the induction of lisogeny but other groups, not detected in the controls, appears after the incubation with mitomycin. In the marine zone of the estuarine system Ria de Aveiro 27% of particles counted as viruses are bacteria but in the brackish water zone only 14% of those particles are counted as viruses. Although the occurrence of lysogeny in the estuarine system Ria de Aveiro is not high, seasonal variation in the fraction of lisogenic cells suggests that lisogeny can be influenced by changes in temperature, salinity and in the intensity of UV radiation. When epifluorescence microscopy is used to count viral particles, viral abundance can be overestimated, namely in the marine area.
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Baker, Nina Crampton. "High alumina cement in the marine environment." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316529.
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Rupe, Blake R. "Domestic and international environmental policy in Mexico : compounding issues for the marine environment." Thesis, The University of Iowa, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1560693.
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Mexico is home to almost 2.9 million square kilometers of land and water surface area that is affected by water pollution and environmental degradation. While geographically more prevalent to pollution threats as well as one of the most biodiverse countries in the world, it is important to coordinate the management and regulation of coastal zones effectively to safeguard these ecosystem from degradation. However, because of the UN Convention on the Law of the Sea, nations view the problem of living resources and their management as a national priority instead of an international cooperation initiative. Mexico's fragmented, overlapping, and sometimes corrupt domestic institutions for environmental policy yield ineffective and inadequate pollution control, a result of which is a high level of marine debris presence on the coasts, as evidenced by a recent study in Veracruz, Veracruz. This marine debris, the most abundant of which is composed of plastics, is detrimental to marine life, leading to death, starvation, debilitation, reduced quality of life and lowered reproductive performance. While several avenues are being explored to mitigate marine debris in the environment, such as decreasing knowledge gaps, increasing pollution prevention measures, and education, degradation issues have compounded globally, revealing a clear picture of inadequate international regulation and convention. A stricter Mexican national regulatory system that incorporates private and public waste management organizations to incentivize and facilitate waste cleanup is needed to improve the health of the global ocean.
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Hess, Philipp. "The determination and environmental significance of planar aromatic compounds in the marine environment." Thesis, Robert Gordon University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388494.
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Effendi, Irwan. "Survival of Aeromonas salmonicida in the marine environment." Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1369.
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Kitidis, Vassilis. "CDOM dynamics and photoammonification in the marine environment." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247925.
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Al-Rabiah, Abdul-Rahman A. "Concrete durability in the Arabian Gulf marine environment." Thesis, University of Salford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334023.
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Pengprecha, Paramee. "Investigation of arsenic behaviour in a marine environment." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU143431.
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The conversion of arsenic into organoarsenic compounds is affected by the action of organisms, particularly marine organisms. These arsenic species require a suitable technique to distinguish the species and quantify their abundance. The ICP-MS coupled to either HPLC or HG-CT are the most popular techniques for arsenic species could be separated, but the limit of detection (LOD) was not satisfactory for the concentration of arsenic in natural waters and the chloride interference in the marine samples was high. While the HG-CT-ICP-MS, the LOD was sufficient to detect very low concentrations of arsenic, particularly for methylated arsenic species, and there was no chloride interference, however the inorganic arsenic in the reagents was high and only the reducible arsenic species could be detected. The transformation of organoarsenic compounds, specifically the conversion of arsenosugars by micro-organisms in sediment, was studied by analysing porewater from decaying seaweed in a mesocosm experiment. Arsenosugars degraded to DMAE further to DMAA to MMAA and finally to As(V) and As(III), but not as previously proposed to AsB, AsC and TMAO. Arsenic was released by the dissolution of manganese and iron clay particles in a pristine area but much more by anaerobic degradation in an industrial area. Arsenic was removed from the water phase to the sediment by precipitation, particularly with manganese at the surface sediment only in the pristine area but with iron in the industrial area.
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Brandes, Jay Allen Gregory. "Isotopic effects of denitrification in the marine environment /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/11051.
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Sharma, S. L. "Hydrocarbon degradation by microorganisms from the marine environment." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1999. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2938.
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Marchioni, Meredith Ann. "Attitudes towards the Marine Environment and Implications for Marine Resource Management in Seward, Alaska." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/192.
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This research, conducted in 2006-2008, examines the ways in which various groups involved with the marine resources of Seward, Alaska construct attitudes towards the environment. Participant observation and semi-structured interviews are used to assess how commercial halibut fishers, tour boat operators, local residents and government officials understand the marine environment based on their previous experiences. This study also explores how ideologies relate to the current practices of each group. Two theories orient the analyses: The first, cultural modeling provided a theoretical and methodological framework for pursuing a more comprehensive analysis of resource management. The second, Theory of Reasoned Action (Ajzen and Fishbein 1980), guided the analysis of the ways in which each participant’s ideology towards the marine environment relates to their practice. Aside from contributing to a better understanding of a coastal community’s ideologies and practices, this dissertation sought to better understand the role of ecological ideologies and behaviors in fisheries management. The research illustrates certain domains where ideologies and practices concerning Pacific halibut and the marine environment differ among commercial fishers, government, and management officials, tour boat operators and residents of Seward, AK. These differences offer insights into how future collaborative efforts between government officials, managers and local marine resource users might better incorporate local ideology into management, and provide ecological information to local marine resource users in culturally appropriate ways.
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Biber, Nicolas Francis Alexandre. "Plastic fragmentation in the environment." Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/6568.
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Microplastics are small piece of plastic debris < 5 mm in diameter, which arise and enter the environment either as a consequence of the direct release of small pieces of plastic debris or as a consequence of the fragmentation of larger items. They are widely distributed in the marine environment, on shorelines, at the sea surface, on the seabed. They are also ingested by a variety of marine organisms, and there is some evidence that this may cause adverse effects. This thesis investigates the potential sources, distribution and fate of this contaminant. Deterioration of plastics in a variety of environments was examined as a potential source of microplastics. Plastics were exposed in light and shade, in air, fresh water and sea water. Their deterioration was monitored over six hundred days. The fastest rate of deterioration, by far, was observed in air, and this was further accelerated by natural sunlight. Degradation in water was much slower and it was therefore concluded that plastic debris only fragments slowly into microplastics while they are in the water, and much faster when they are washed ashore and/or remain exposed to air, for example on a beach. A method to assess the contamination of beaches by microplastics' likely predecessors - small items of plastic debris - was therefore developed. High spatial variability, which can impede comparison between surveys undertaken by random sampling was overcome by assessing deliberately selected debris accumulations. An attempt to utilise citizen science using this rapid survey approach returned too much variability between volunteers to obtain consistent results. Nevertheless, the survey method was successfully used to identify narrow opening towards the sea, small tidal range and several weeks of high on-beach waves as predictors for high contamination. Evidence of harmful effects of microplastics on animals is primarily from laboratory studies and could be substantiated by exposure experiments \emph{in-situ}. Cockles were exposed to fluorescent plastic particles in an intertidal mudflat. After two weeks, particles were still present in the sediment. However, the test material could not be identified in the cockles with enough certainty to validate the method. The thesis concludes that fragmentation of larger items of debris on land is an important potential source of microplastics. Therefore, preventing plastics that are prone to deteriorate from entering the environment is likely the most effective way to prevent the generation of microplastics. Measuring the success of such preventive measures in the field returns highly variable results, as small plastic debris are elusive. Measuring effects in the environment demands large amounts of data, and highly specific methods are required to detect microplastics in animals. The shift of environmental plastic contamination towards small particles demands that plastic debris research adjusts to the elusiveness of these particles. Large volumes of variable data on plastics density and precise biological essays will be required.
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Yu, Pui-shan. "The potential for using biomonitoring in the Hong Kong marine environment /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17457622.
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Lambelet, Myriam Liliane. "Cadmium and neodymium geochemical cycles in the marine environment." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/34397.
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The roles of trace elements and their isotopes in the marine environment are essential and diverse (e.g., nutrients, tracers of oceanic processes, anthropogenic pollutants), but are not well understood yet. In this thesis, two elements and their isotopes were investigated in two distinct marine environments: cadmium (Cd) in the Siberian shelf seas and neodymium (Nd) in the western North Atlantic Ocean. Whereas the role of Cd as nutrient in the open ocean is reflected by Cd isotope data, its behaviour in estuaries is poorly constrained. Chapter 2 of this thesis presents new Cd isotopes and concentrations of 19 water samples from the mixing zone of Siberian rivers with the Arctic Ocean. The results provide the first constraints on the isotope composition of natural riverine Cd fluxes to the ocean and the cycling of Cd in a shelf environment. Chapter 3 describes the method developed to isolate and analyse seawater Nd isotopes and concentrations in the MAGIC laboratories. The Nd isotopic composition of seawater is a promising tracer for ocean circulation and exchange between the continental margins and the oceans. By analysing 12 seawater depth profiles from the Dutch GEOTRACES transect GA02 (Chapters 4 and 5), we demonstrate that Nd features different behaviour in regions close to the formation area of deep water masses compared to export areas, where it behaves conservatively away from continental margins. Besides, we show that upper- North Atlantic Deep Water (NADW) and lower-NADW have distinct Nd isotopic compositions, and that the signature of lower-NADW is significantly more radiogenic than the commonly accepted value, which should be taken into account for future applications. Overall, the present thesis underlines the important role that isotope analyses can play in deciphering marine biogeochemical cycles of trace elements.
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Hackenberg, Sina Corinna. "Quantifying isoprene and monoterpenes in the remote marine environment." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/12195/.
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Measurements of isoprene and six monoterpenes (alpha- and beta-pinene, myrcene, delta3-carene, ocimene and limonene) were made during research cruises in the Atlantic Ocean and Arctic (80 degrees N - 50 degrees S). The trace gas species were quantified in the surface ocean, in depth profiles and in the marine boundary layer (MBL). Atmospheric mixing ratios of the analytes were typically below the detection limit (DL) to a few pptv over the Atlantic and mostly < DL (sub-pptv) in the Arctic, after careful quality control to exclude influence from contaminated air. Isoprene mixing ratios were similar to published observations in oligotrophic regions, but monoterpene levels much lower than previously reported. It is unclear whether this discrepancy is caused by sampling over lower-productivity waters, or by analytical differences including potential contamination. Isoprene concentrations in the surface ocean varied from ca. 1 to 70 pmol L^(-1), similar to the majority of previous studies, and correlated reasonably with several supporting biological parameters available for the cruises. Chlorophyll-a, various pigments including photoprotective carotenoids and Fucoxanthin, cyanobacterial cell counts and primary production yielded significant linear regressions (with R^2 = 0.4 - 0.6), which improved when separated into two temperature regimes with a threshold at 20 degrees C. Monoterpene concentrations in seawater are reported for the first time, varying from < DL (sub-pmol L^(-1)) to up to several pmol L^(-1) with no clear trends or relationships with biological data. The monoterpene generally showing the highest levels in water and air was limonene; however this was attributed mostly to contamination. The impacts of emissions derived from this new data on global atmospheric chemistry and secondary organic aerosol formation in the MBL were estimated to be small in light of recent literature and previously published marine terpene data; however they may play a role in nucleation processes as recently suggested, even at low concentrations.
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Wilson, Sam T. "The production of biogenic gases in the marine environment." Thesis, Open University, 2007. https://pure.uhi.ac.uk/portal/en/studentthesis/the-production-of-biogenic-gases-in-the-marine-environment(932c755e-35e5-46f0-823d-426afa30d3a2).html.
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The biogenic trace gases dimethylsulphide (DMS) and methane play a major role in the Earth’s climate and atmospheric chemistry. DMS makes a significant negative contribution to radiative forcing and methane is an important greenhouse gas. The marine environment is an important source of both DMS and methane and this thesis investigated the interactions between methylated sulphur compounds and methanogenesis within micro-environments in the upper-water column. The production of DMS is closely associated with dimethylsulphoniopropionate (DMSP) and dimethylsulfoxide (DMSO) although comparatively little is known about the dynamics of DMSO in the marine environment. This study analysed the production of DMSO by a range of marine phytoplankton species in comparison with DMSP. Algal concentrations of DMSO were taxon-dependent and an average DMSPp:DMSOp ratio of 4.85 was calculated for the phytoplankton species analysed. The consistent presence of DMSO at ~20 % of total intracellular methylated sulphur (DMSP + DMSO) suggests it is an important algal consituent. The fate of DMSP and DMSO produced by algal cells was analysed in a series of grazing experiments with the copepods Temora longicornis and Acartis clausi, and the dinoflagellate Scrippsiella trochoidea. The relative importance of assimilation, sloppy feeding, DMS production and excretion of faecal pellets as sinks for algal-DMSP was calculated. In comparison to the ambient marine environment, both algal cells and copepod faecal pellets were identified as micro-habitats of elevated DMSP and DMSO concentrations. Millimolar concentrations of DMSP were measured in algal cells and micromolar concentrations of DMSP were recorded in copepod faecal pellets. These hotspots of DMSP and DMSO may be associated with chemical processes that differ from bulk seawater characteristics, such as the transformation of DMSO as revealed in coastal pelagic particulate material. Furthermore, oxygen depletion at the micro-scale could facilitate the presence of anaerobic bacteria, or anaeorobic bacterial activity, in the predominantly aerobic pelagic environment. The occurrence of methanogenic Archaea specifically associated with copepod faecal pellets from mono-species cultures of copepods, environmental samples and total pelagic particulates was investigated using 16S rRNA gene libraries. Clusters of sequences closely related to Methanogenium, Methanobacterium and Methanolobus were recovered. This work revealed that CO2-reducing methanogens can exist in the pelagic environment where it was previously assumed methylotrophic methanogenesis dominated. This work demonstrated that the methylated sulphur compounds represent a metabolic substrate for methanogens in the upper water column. The addition of DMSP, DMSO and DMS to samples collected from the upper water column stimulated methanogenesis when incubated under anaerobic conditions. The addition of inhibitors suggest that other anaerobic bacteria e.g. sulphate-reducing bacteria, may play a key role in this process. The potential for DMSP and DMSO to serve as precursors for methane, a potent greenhouse gas, as well as DMS, has important implications when considering the emissions of these compounds from the marine environment and their role in the Earth’s climate.
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Morley, Thomas G. "Augmentation of GPS with pseudolites in a marine environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24721.pdf.
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Budge, Suzanne M. "Fatty acid biomarkers in a cold water marine environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0012/NQ52692.pdf.
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Clegg, Nicola Aylsa. "Modelling sea-salt aerosol composition in the marine environment." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286292.
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Jamal, Mamdoh Taha. "Studies on antibiotic-producing bacteria from the marine environment." Thesis, Heriot-Watt University, 2007. http://hdl.handle.net/10399/2044.
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Of >500 bacterial isolates from seaweed, namely Fucus serratus, algae (Halimeda sp, Sargassum sp), sponges (Siphonochalina sp, Leucetta 'chgosensis), sea cucumber, (Holothuria atra), star fish (Acanthaster planci), mangrove (Avecenia marina) roots, sea anemone, (Heteractis magnifica), ,jellyfish (Disambiguation), sediment and seawater from the Scottish and Saudi Arabian coasts, a culture of Bacillus licheniformis produced a novel protein with antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and Listeria monocytogenes. The antibacterial activity was maximal in cultures prepared in Columbia broth -containing pieces of synthetic polyurethane sponge and shaken at 210-230 rpm. Antibacterial activity was not found in cultures grown statically or with different speeds of rotary shaking. Reduced activity was apparent in supernatants prepared from marine . 2216E broth and tryptone soya broth with or without 1% (w/v) sodium chloride. The antibacterial compound was sensitive to proteinase K, pronase and trypsin, but was not affected by Tween 20, 40, 60 or 80, or a- or ~-amylase. Activity was not adversely affected by heating to 40°C or treatment at pH 5-14. The bioactive compound was purified by gel filtration and ion exchange, and classified by using MALDI-TOF determined as a protein of 30.7 kDa, which had homology to the YbdN protein of B. licheniformis ATCC 14580. The gene encoding YbdN was isolated and transferred to Escherichia coli XL BLUE, and the product was purified by SDS-PAGE giving a single band with a molecular size 30.7 kDa.
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Zylinski, Sarah. "Cuttlefish : Camouflage and Visual Imaging in the Marine Environment." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499627.
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Rose, Andrew Stuart. "Epidemiological aspects of Aeromonas salmonicida in the marine environment." Thesis, University of Stirling, 1990. http://hdl.handle.net/1893/21887.
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The epidemiology of Aeromonas salmonicida subsp. salmonicida in the marine environment was investigated. Nutrient resuscitation and infectivity studies did not support a previous claim of dormancy in A. salmonicida and validated the use of colony-forming units (cfu) in survival studies. Survival of A. salmonicida in seawater was assessed and found to be of short duration «10 days). Survival of the bacterium in non-sterile sediment, obtained from beneath a salmon cage, appeared to be limited. The minimum infective dose of A. salmonicida to Atlantic salmon in short duration (1-3 days) bath exposure in sea water was 10' cfu ml-I. Prolonged exposure for three weeks resulted in infection with 102 cfu ml- I. Intragastric intubation of the bacterium established infection with doses >105 cfu. Shedding of A. salmonicida from infected salmon was 105-108 cfu/fish/hr. Survival and shedding results were combined in a computer model. A. salmonicida was predicted to travel >6 km suspended within the water column of a sea loch. Covert infection in freshwater farmed salmon was assessed by ELISA and the standard stress test. Results indicated that ELISA may be useful as a routine monitor of furunculosis infection. The efficacy of dot-blot immunoassay was found to be 108 cfu A. salmonicida in fish kidney tissue. Rainbow trout (Oncorhynchus mykiss) and salmon mucus were not found to inhibit the growth of A. salmonicida supporting recent evidence that fish skin is a site of carriage. In vitro studies suggested that trout serum proteins do not confer protection from fish antibody on A. salmonicida in covert infections. Preliminary work was undertaken to develop a specific DNA probe for A. salmonicida which will allow its detection in environmental samples and carrier fish. A gene library of A. salmonicida was constructed in lambda gtll and screened for "A"-protein with antibodies.
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Starr, Sean Michael. "Microbial methane oxidation in the marine and estuarine environment." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313378.
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Byfield, Valborg. "Optical remote sensing of oil in the marine environment." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284675.
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Al-Shaeri, Majed Ahmed M. "The ecotoxicology of carbon nanotubes in the marine environment." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/3042.
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With their high aspect ratio, strength, light weight and electrical conductivity single-walled carbon nanotubes (SWCNTs) provide properties of great interest to industry, and, consequently, are finding use in an ever increasing number of products and applications, which will eventually lead to their appearance in the environment. The toxicity of SWCNT, however, is controversial, mainly because of the inconsistency of results, owing to a lack of understanding of the behaviour of SWCNTs in environmental media. The present study explored the ecotoxicology of engineered SWCNTs and their interacton with other contaminants as well as their potential for trophic transfer. A series of co-contaminant experiments was performed to understand the interaction of SWCNTs with dissolved metals at low-level and non-toxic concentrations of both. The results showed that any nano-scale effects were negated by the tendency of uncoated SWCNTs to agglomerate in seawater. However, SWCNTs, in combination with natural organic matter (NOM), remained suspended for long enough to become available to filter-feeding mussels. A potentiating toxicological effect was observed, expressed as DNA strand breaks obtained using the comet assay and oxidative stress, on divalent metals afforded by negatively charged SWCNT agglomerates in seawater at concentrations as low as 5μg L-1. This is supported by the observation that SWCNTs alone were only toxic at concentrations ≥100μg L-1 and that the SWCNT-induced DNA damage was correlated with oxidative stress only in the absence of metals The potential for trophic transfer was assessd using the green algae (Tetraselmis suecica). Light microscopical observations, confirmed by SEM and Raman spectroscopy, showed that SWCNTs adhered to the external algal cell walls and TEM results suggested internaization. A direct effect of SWCNT exposure on the algae was a significant decrease in chlorophyll a concentrations and cell viability. Algea fed to mussels in the presence of SWCNTs led to a signifiacntly increased pseudofaeces production, suggesting selective feeding. However, histological sections of the mussel digestive gland following exposure showed evidence of SWCNTs containing algal and toxicological tests signs of DNA dmage and oxidative stress. In conclusion, the observed SWCNT-algal interaction may facilitate trophic transfer of SWCNTs up the food chain with potential consequences for human health. If these laboratory experiments are confirmed in the natural environment, the present results will have implications for the understanding of the role of carbon nanotubes in environmental metal dynamics, toxicology, and consequently, regulatory requirements.
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Mackechnie, James Ronald. "Predictions of reinforced concrete durability in the marine environment." Doctoral thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/21728.
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This thesis presents an investigation where an empirical method is proposed for predicting the durability of reinforced concrete structures in the marine environment. The objective was to identify reliable means of characterizing early-age properties of concrete which affect durability and relate these to the durability performance of the material under marine conditions. Establishing a relationship between early-age testing and long-term performance of concrete is a necessary precursor to implementing a system of performance-based durability specifications.
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Karin, Abrahamsson. "Load Bearing Structural Elements of Glulam in Marine Environment : A literature and case study." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-79056.
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This thesis discusses the possibilities of using glued laminated timber as load bearing structural elements in structures in close vicinity of saltwater. Glued laminated timber, also referred to as glulam, is a refined timber product constructed of timber lamellae that are glued together. The thesis contains a literature study and a case study that covers glulam beams in a pedestrian jetty located on the Swedish west coast. The literature study addresses wood in relation to moisture, the effects that salt may have on wood in a marine environment, wood decaying mechanisms and suitable wood preservatives to prevent decay. The literature study also covers glulam as a material and the possibilities of wood pressure impregnation. A method of estimating the service life of timber elements is also discussed. The results of the literature study were applied in a case study of a specific case, to explore the possibility of replacing the current steel beams of the structure with glulam beams. From the case study, the strength and deflection of the prospective glulam beams were calculated. Service life of the prospective glulam beams was estimated based on the environment they would be exposed to. An analysis of the market for glulam products in Sweden was also performed to find out what dimensions and wood impregnation classes are available. The results of the literature study show that glulam can be used as main load bearing elements in a marine environment, given that the structure is placed above sea level. Salt water does not affect the wood, rather it works as a wood preservative and gives some protection against rot. However, the structure is subjected to high moisture content and pressure impregnation is necessary. The high moisture content also affects the mechanical properties of the wood as the strength and stiffness of glulam decrease with increasing moisture content. Creep of the material is also affected as it increases with increased moisture content. Regarding strength and deflection, the results of the case study show that glulam beams available on the Swedish market are of sufficient dimensions to be used. Regarding service life, the case study showed that the estimated service life of the glulam beams is only 19 years, but the service life required is 50 years. The current structure design with prospective glulam beams does not meet the requirements for durability of the material. However, suitable design changes regarding wood moisture protection could increase service life of the glulam beams.Denna rapport behandlar möjligheterna till att använda tryckimpregnerat limträ som huvudbärverk i konstruktioner i nära anslutning till saltvatten. Limträ är en träprodukt bestående av trälameller som limmats samman till större träelement. Rapporten består av en litteraturstudie och en fallstudie som behandlar limträbalkar i en promenadbrygga belägen på den svenska västkusten. Litteraturstudien avhandlar trä i förhållande till fukt, eventuell påverkan av salt i en marin miljö, nedbrytningsmekanismer för trä samt lämpliga träskydd för att förhindra nedbrytning. Litteraturstudien behandlar även limträ som material och möjligheterna till tryckimpregnering. En metod för att uppskatta livslängden av trä diskuteras också. Resultaten från litteraturstudien applicerades i en fallstudie för ett specifikt fall, för att undersöka möjligheterna att ersätta den nuvarande konstruktionens stålbalkar med limträbalkar. Utifrån fallstudien beräknades hållfastheten och nedböjningen av de tilltänkta limträbalkarna. Livslängden på de tilltänkta limträbalkarna uppskattades baserat på den miljö de skulle komma att utsättas för. En analys av marknaden av tryckimpregnerade limträprodukter i Sverige genomfördes också för att se vilka dimensioner och tryckimpregneringsklasser som finns att tillgå. Resultatet från litteraturstudien visar att limträ kan användas som huvudbärverk för marina konstruktioner med kravet att konstruktionen placeras ovanför vattenytan. Saltvatten påverkar inte träet negativt utan verkar snarare som träskydd mot röta. Dock utsätts konstruktionen för hög fuktkvot och måste därför tryckimpregneras. Det höga fuktinnehållet påverkar även de mekaniska egenskaperna av träet då hållfastheten och styvheten av limträet minskar med ökande fuktkvot. Krypningen av träet påverkas också, då krypning ökar med ökad fuktkvot. Med avseende på hållfasthet och nedböjning visade resultatet av fallstudien att tryckimpregnerat limträ som kan erhållas från den svenska marknaden är av tillräckliga dimensioner för att kunna användas. Avseende livslängd visade fallstudien att den undersökta konstruktionens estimerade livslängd endast är 19 år. Dock är den erfordrade livslängden för träkonstruktionen 50 år. Dagens konstruktion möter inte kraven på materialets varaktighet, men längre livslängd skulle kunna erhållas genom lämpliga designändringar avseende limträbalkars skydd mot fukt.
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Ting, Matthew Zhi Yeon. "Strength and Durability of Concrete Incorporating Industrial Wastes, Marine Sand and Seawater Exposed to Marine Environment." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/85767.
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This research investigates the performance of concrete incorporating marine sand, seawater, silicomanganese slag, fly ash and silica fume for application in marine environment. The effect of sulphate attack coupled with wetting-drying action on durability and fatigue behavior of concrete is studied using experimental and numerical methods. Through optimization using statistical analysis, a more sustainable concrete, with better strength and durability than the conventional type, is developed which is suitable for direct industrial use.
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Robinson, David Iain. "Multi-scale modelling of effluent dispersion in the marine environment." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/34690.
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This research aimed to investigate whether the unique numerical methods available within CFD model software Fluidity could progress the state-of-the-art in various aspects of modelling effluent dispersion within the marine environment. Fluidity contains a large library of models and numerical methods that enable modelling of flow processes at a wide range of scales. It has been proven to perform well when used for massively-parallel simulations (i.e. it scales well), and it has the uncommon facility of unstructured mesh adaptivity, which has the prospect of significantly increasing the efficiency of CFD simulations when guided skillfully. This research also forms part of a longer-term project to create a coupled (or even single) model of effluent dispersion that represents influencing factors from a wide range of scales (from tidal currents down to turbulent eddies) entirely using CFD techniques. As such, one aspect of the research was to validate the numerical methods available within Fluidity for use in modelling effluent dispersion. To facilitate this validation, some of the model studies investigate aspects of effluent dispersion modelling from a hypothetical outfall site off the North-East coast of the United Kingdom. Studies were performed in a series of stages in which key aspects of effluent dispersion modelling were addressed. CFD models were created of near-field jet dispersion, tidal motion, and far-field plume dispersion. Idealised test cases were also performed to investigate the performance of advection-diffusion solver methods. At each stage the aim was to investigate the benefit of novel numerical modelling techniques and compare their accuracy and efficiency to existing methods. A set of near-field buoyant jet dispersion CFD models were created, one representing conditions associated with power, and combined power and desalination plants, and one representing conditions typically associated with desalination discharge. These CFD models utilised a mesh adaptivity algorithm to optimise mesh resolution during the course of the simulation. Model predictions were compared with published laboratory data and the predictions from validated integral models. An assessment was made of when CFD offers a benefit over other modelling options, and when it might be sufficient to use cheaper tools. There was also a discussion of the effectiveness of mesh adaptivity in increasing model efficiency, together with advice for how and when it is best to use mesh adaptivity when modelling buoyant jet dispersion. Model results showed that with modest parallel computing resources and expertise, high-resolution simulations of jet dynamics can be achieved with reasonable accuracy using CFD modelling. A model was created of tidal flow within the European continental shelf and results were compared to a large database of tide gauge measurements. This model took advantage of recently published methods for ocean model meshing and coastline resolution reduction. The purpose of this study was to confirm that these methods offered a benefit to model accuracy and efficient, and also that Fluidity could be used to accurately generate the tidal forcing boundary conditions for a far-field model of effluent dispersion at a hypothetical outfall site. The predictions of M2 tide amplitude in the vicinity of the outfall site had an average error of 10.1% compared with tide gauge measurements. The predictions of S2 tide amplitude in the vicinity of the outfall site were even closer to tide gauge measurements, with an average error of 3.7%. The speed of the model solve showed a vast improvement over a previous comparison model study, with 37 days of tidal motion being simulated in 15.2 hours (58.4 seconds of simulation for each second of solving), compared to the comparison simulation with a similar level of accuracy, which simulated 2 seconds of tidal motion for every second of solver time. A series of simplified test cases were run to assess a commonly-used advection-diffusion solution method from the library of those available within Fluidity. This work was intended to give general confidence that the numerical methods available within Fluidity are suitable for modelling coastal processes and so give confidence in later multi-scale results. The test cases chosen were relevant to coastal dispersion, including those testing tracer advection, diffusion, point sources and stratification. The method compared well with results published using world-leading free surface modelling software, Open TELEMAC. A model was created of the dispersion of neutrally-buoyant dissolved pollutant from a hypothetical outfall. The assumed effluent is typical of that released from a manufacturing plant. The aim of this modelling was to validate the use of Fluidity for modelling effluent dispersion within the coastal zone, and also investigate the benefit of using 2-d horizontal mesh adaptivity to optimise model mesh resolution during the course of the simulation. It was shown that the use of mesh adaptivity improved model efficiency, significantly lowering the effect of numerical diffusion. Finally, a short outline was given of a prospective strategy for producing a coupled-model of effluent dispersion, using as a basis the techniques developed within this thesis. The proposed coupled model of effluent dispersion would include a near-field jet model two-way (i.e. 'fully-coupled') to a far-field plume model. Tidal forcing would be provided by a one-way coupled tidal model. Fluidity is capable of modelling all of these processes and so third party coupling software would be unnecessary.
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Gerard, Jeffery M. "Antibiotic secondary metabolites of bacteria isolated from the marine environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25055.pdf.
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Fung, Chi-tuen. "Approaches to assess heavy metal toxicity in the marine environment /." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B3712030X.
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Brooke, Cassandra. "Marine pollution management under the Environment Protection Act 1993 (SA) /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09ENV/09envb872.pdf.
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Al-Zaidan, Amina S. "Mathematical modeling of marine environment contamination using fuzzy set theory." Thesis, Bangor University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248901.
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Poon, Sau-man Anne, and 潘秀文. "Dredging and reclamation impact on marine environment in Deep Bay." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31253866.
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Fung, Chi-tuen, and 馮志端. "Approaches to assess heavy metal toxicity in the marine environment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B45013378.
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Lin, Ching-nga, and 林靜雅. "Characterization of a novel streptococcus species associated with marine environment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46699521.
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Thompson, Andrew Sydney. "The microbial oxidation of methanesulfonic acid in the marine environment." Thesis, University of Warwick, 1995. http://wrap.warwick.ac.uk/59057/.
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The biogeochemical transformations related to methanesulfonic acid (MSA) formation and degradation are discussed, with reference to the role of marine bacteria and the phylogeny and biochemistry of methylotrophic bacteria are briefly reviewed. The aims of the work presented were [i] to isolate novel MSA utilising bacteria from both seawater and freshwater samples, [ii] to characterise these isolates and [iii] to elucidate the mechanisms by which MSA is metabolised in these isolates. Isolation procedures for the enrichment of MSA-oxidizing bacterial from a wide range of seawater and freshwater sites, are described. Four methylotrophic bacterial strains, TR3, PSCB4 (marine isolates), FW2 and FW6 (freshwater isolates), capable of growth on MSA as a sole carbon source were isolated from the environment. MSA metabolism in strains TR3 and PSCB4 was initiated by an inducible NADB-dependant monooxygenase, which cleaved MSA into formaldehyde and sulfite. Formaldehyde was assimilated via the serine pathway. Cell suspensions of bacteria grown on MSA completely oxidized MSA to carbon dioxide and sulfite with a MSA: Oxygen stoichiometry of 1.0: 2.0. Oxygen electrode-substrate studies indicated the dissimilation of formaldehyde to formate and C02 for energy generation. Methanol was not an intermediate in MSA metabolism, although the strains could grow on methanol and other one-carbon compounds, as well as a variety of heterotrophic substrates. Initial studies of strains FW2 and FW6 indicated that they probably metabolised MSA in a similar way to the marine strains. Carbon dioxide was not fixed by ribulose bisphosphate carboxylase in strains TR3 and PSCB4. These novel facultative methylotrophs have the ability to mineralize MSA and may play an important role in the cycling of global sulfur, since MSA can be a major product from the oxidation of DMS, the principal biogeochemical organosulfur gas in the environment.
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Galarza, Juan Antonio. "Patterns and causes of population subdivision in the marine environment." Thesis, University of Hull, 2007. http://hydra.hull.ac.uk/resources/hull:1611.
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An accurate assessment of population genetic subdivision is crucial in making informed decisions for the management and conservation of marine resources. However, obtaining a precise assessment is particularly challenging since population subdivision results from the interaction of many biological and environmental variables. Here, the patterns of population subdivision that can be attributable to gene flow in 8 marine fish species from 11 different locations in the Mediterranean Sea and the Eastern Atlantic Ocean are analysed. The species considered are Mullus barbatus, Mullus surmuletus, Tripterygion delaisi, Apogon imberbis, Symphodus tinca, Diplodus vulgaris, Serranus cabrilla and Oblada melanura. These species differ significantly in their dispersal capabilities as presumed by their diverse early-life stage characteristics, and were sampled over multiple habitats at two geographical scales. A total of 1640 individuals (mean 168/species) were surveyed at 63 species-specific and 10 cross-amplified microsatellite loci (mean 9.1/species). The overall results show that genetic structure patterns cannot be predicted confidently by the presumed dispersal capabilities of the species. Species such as S.tinca, M.barbatus and O.melanura, showed highly incongruent population structuring patterns to those expected. Furthermore, the results also suggest that species with extreme variations between their life history traits such as D.vulgaris and A.imberbis, can display similar patterns of genetic structuring in the presence of common oceanographic variables, whereas species with slight differences such as M.barbatus and M.surmuletus can display contrasting patterns of genetic partitioning. These results highlight the importance understanding the role of environmental features and life history traits in establishing ecologically meaningful connections among marine fish species. Furthermore, this study provides evidence of the usefulness of multi-species approaches in planning to incorporate population genetic information into conservation and management of marine fish resources.
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McKee, Conor Michael. "Biogeochemical cycles of ammonia and dimethylsulphide in the marine environment." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368388.
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Chuck, Adele Louise. "Biogenic halocarbons and light alkyl nitrates in the marine environment." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251499.
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Smith, B. D. "State responsibility and the marine environment : The rules of decision." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372921.
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Scott, Paul. "Aspects of CFRP prestressed concrete durability in the marine environment." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611710.
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