Thesis (M.Arch.)--University of Hong Kong, 1999. / Includes special report study entitled : Methods of offshore construction. Thesis report lacks content page. Includes bibliographical references. Also available in print.

Thesis (M.Arch.)--University of Hong Kong, 2002. / Includes special report study entitled : Urban waterfront and space. Includes bibliographical references. Also available in print.

Thesis--Lehigh University.

Thesis (Ph.D. (Zoology & Entomology)) - Rhodes University, 2007.

Th.--Hist.--Helsinki, 1979. / Bibliogr. p. 309-316. Résumé en anglais.

The subtidal whelk Burnupena papyracea (Brugière) co-occurs with a voracious predator, the rock lobster Jasus lalandii (Milne Edwards), in situations where other potential prey are largely eliminated. This has been ascribed to a symbiotic bryozoan, Alcyonidium nodosum (O’Donoghue and de Watteville), which characteristically encrusts the shells of B. papyracea and deters feeding by Jasus. In this study it is shown that this is not due to physical effects of either induced physical defences in the bryozoan or increased shell strength due to the presence of the bryozoan. Neither spectroscopic screening of chemical extracts of the bryozoan nor analysis for volatile constituents revealed any apparent chemical components that are likely to deter feeding. Chemical extracts also failed to show larvicidal effects in a standard toxicity assay using the brine shrimp Artemia salina (Leach). Despite this, bioassays using individual Jasus indicated a chemical basis for feeding deterrence. The assays were run separately on three sets of Jasus and some repeats of assays gave contradictory results. However, assays showing no significant effect of treatment occurred with moulting Jasus, involved very low overall feeding rates and so gave a less convincing result. In other assays Jasus always avoided Burnupena papyracea with live Alcyonidium encrusting the shell, and food pellets containing Alcyonidium or an Alcyonidium extract. Significant preferences were shown for an unencrusted whelk, B. cincta (Röding), over B. papyracea; for B. papyracea with the bryozoan scraped off over natural B. papyracea; for B. papyracea on which the bryozoans had been killed with liquid nitrogen over untreated B. papyracea; and for food pellets prepared from ground, dried mussel over pellets prepared with dried mussel mixed with A. nodosum or its crude organic extract. It is concluded that the protection which Alcyonidium confers on Burnupena papyracea does have a chemical basis, but that the chemical responsible is either present in only trace quantities, or that it is a structurally unremarkable compound which is distasteful to Jasus. This work highlights both the advantages of using ecologically relevant bioassays (positive results when standard techniques give a negative result) and also the disadvantages (logistic constraints on sample sizes when using large test animals and individual variability in a relatively sophisticated test animal).

No description available.

No description available.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / A combination of overexploitation and destructive fishing practices, such as bottom trawling, have depleted native populations of groundfishes in coastal New England and reduced benthic community diversity. The Stellwagen Bank National Marine Sanctuary (SBNMS) in the southern Gulf of Maine is partially overlapped by the Western Gulf of Maine Closed Area (WGMCA). The WGMCA is closed to commercial fishing for groundfishes managed under the Northeast Multispecies complex and the use of bottom trawling fishing gear is prohibited to protect essential fish habitat. This has reduced fishing pressure and benthic disturbance levels. The area of the SBNMS outside of the WGMCA is still disturbed by intensive commercial fishing for much of the year. Key questions for this area are (1) How does the higher level of disturbance in areas outside of the WGMCA affect SBNMS groundfish communities?, (2) Is the WGMCA effective at increasing the diversity, abundance, and biomass of groundfishes in the SBNMS?, and (3) How does the decrease in disturbance impact groundfish trophic ecology? A comparison of the groundfish communities inside and outside of the WGMCA within the SBNMS was carried out via trawl sampling. Results show that groundfish communities are more diverse inside the WGMCA than outside. Additionally, several commercial groundfish species had higher abundance and/or biomass inside the WGMCA. Stable isotope analyses showed that prey items differed for some species inside and outside of the WGMCA, but trophic levels were unaffected. Finally, stable isotope analyses of five groundfish species provide evidence that groundfishes may display a high level of foraging area fidelity. Primary conclusions include: (1) the protection of groundfish habitats from trawling disturbances paired with reduced fishing pressure will result in increases in community diversity and abundances of groundfishes, (2) groundfish ecology should be considered on a small geographic scale due to apparent site fidelity, and (3) if the entire SBNMS were closed to bottom trawling and commercial fishing, it could help to rebuild overexploited groundfish populations in the southern Gulf of Maine and serve as a source population for the remainder of the Gulf of Maine and adjacent shelf environs. / 2999-01-01

PART ONE. A highly sensitive and reproducible method for the determination of aliphatic amines namely monomethylamine (MMA), dimethylamine (DMA) , and trimethylamine (TMA) in marine environmental samples (water and sediments) has been developed. This involves an initial stage in which the amines are preconcentrated by microdiffusion and subsequently determined using a gas chromatograph equipped with a packed column and Nitrogen Phosphorus Selective Detector (NPSD) . The detection limit is at sub ppb level (ng/l), and the method recoveries are in the ranges of 58-68% for MMA, 55-84.3% for DMA, and 83-105.5% for TMA for the range of concentrations between 2-40 ppb. The percentage standard deviations of the chromatographic measurements are <15.1% for MMA, <11.1% for DMA, and <10% for TMA. The untreated Chromosorb 103 column packing was found to be very stable for more than a year with little deterioration in performance. Using this method, the production of methylamines by a marine phytoplankton has been studied, and has been shown to be greatly influenced by the growth conditions i.e bacteriostatic and nonbacteriostatic culture media, different levels and types of N sources, and zooplankton grazing on the phytoplankton. Maximum concentrations of methylamines were observed in the N03- enriched bacteriostatic medium. Zooplankton grazing also increases their levels. Methylamines were found to be distributed in a range of marine environments, with highest concentrations detected in marine sediments. Their levels were also higher in polluted Mersey waters than in the water off the Isle of Man (10M). MMA was found to be the dominant species in all of these samples (phytoplankton, sediment, and water) and also in the marine atmosphere. Using the same approach, l-Arninopropan-2-one, which has long been known to be a compound of urine, has been shown to be a stable indicator of raw sewage pollution. Its identity has been confirmed by GC-MS of its trifluoro acyl-derivative. Its distribution in estuarine water (Mersey Estuary) and coastal water (Port Erin, 10M) is presented. PART TWO. Volatile organic compounds (VOCs) in phytoplankton cultures, marine sediments, and Mersey Estuary water samples have been determined by a modified Grob closed-loop stripping method and GC-MS analysis. VOCs in the Mersey estuary water samples were dominated by methylated benzenes and methylated naphthalenes. In contrast, chlorinated compounds were the dominant compounds in the sediments, and methylated alkanes in the non-bacteriostatic phytoplankton culture. Some methylated benzenes were also found in the plankton sample, which might explain their observation in some of the remote unpolluted marine environment. This thesis is dedicated to my parents, my wife and children.