Thesis (Ed.M.)--Boston University

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Thesis (Ph. D.)--Columbia University, 1905. / Vita. Published also without thesis note. Bibliography: p. [105]-107.

Extensive data sets of water quality and sediment chemistry as well as detailed historical records were used to analyze environmental factors controlling dinoflagellate cyst distribution in shallow estuaries (lagoons and embayments) of southern New England. Cyst abundance, species richness, the proportion of cysts produced by heterotrophic and autotrophic dinoflagellates, and the composition of cyst assemblages reflect spatial and temporal variation in environmental conditions. The cyst record in sediment cores from two embayments, New Bedford Harbor and Apponagansett Bay, Massachusetts demonstrates cyst sensitivity to environmental change caused by anthropogenic activity in the watersheds. Intensive industrialization and urbanization occurred during the 20th century in New Bedford Harbor resulted in extreme eutrophication and toxic pollution (heavy metals and PCBs). These conditions are reflected in declining cyst diversity and wide fluctuation in total cyst production. At the same time, the proportion of certain heterotrophic taxa increases. As impacts of extreme eutrophication and toxic pollution cannot be separated, the cyst response must be interpreted as a cumulative «pollution signal». The spatial distribution of modern dinoflagellate cysts in the area supports this signal. Cysts vary along gradients of nutrient enrichment, corresponding to distance from sewage outfalls. Dinoflagellate cysts in surface sediments from New England lagoons also were studied. A comparison of assemblages to water quality parameters, that are affected greatly by the degree of water exchange between lagoon and ocean, indicates that temperature and salinity are the main abiotic factors controlling cyst distribution in these estuaries. A new species of dinoflagellate cyst, Islandinium brevispinosum, has been identified and described. This species was found within a narrow range of water temperature and salinity, and at elevated nutrient levels. Dinoflagellate cysts reflect environmental conditions at the small spatial scales necessary to characterize variability within estuaries. However, the relative importance of abiotic factors controlling the spatial and temporal distribution of dinoflagellate cysts is likely to vary with the hydrological differences between lagoons and embayments. Therefore, dinoflagellate cysts can be useful indicators of environmental conditions in and human impacts on shallow estuaries.

Interannual variability of temperature and cyclone frequencies for Eastern Canada and the New England States have been investigated for the winter seasons 1931-32 to 1984-85. Seasonal analyses have revealed that cyclone frequency has decreased by 21% over the research area; the highest losses occurring over the Maritimes and the New England States (30%) and in the southern Quebec-southwestern Ontario region (31%). The seasonal average temperature has remained fairly stable during the research period. However, the Temperature Variability Index (TVI) suggests that the interannual variability of temperature has been through some changes since 1931-32. The latest shift indicates that, since the early seventies, the temperature variability appears to be increasing during the winter season. Half-month periods were analyzed which revealed some features of the climatic variability during the winter season since 1931-32. Average temperature for the first 15 days of January recorded a significant decrease over the last 54 years. On the other hand, the last half of February presented a general increase in temperature. Parallel to that, the last half of January and the first 15 days of February have recorded substantial decreases in cyclone frequency. Thus, these half-month periods reveal trends which indicate that the overall winter season of the mid-seventies--early eighties differs from the prevailing winter climatic conditions of the thirties and forties.

There is no abstract available for this thesis.

Thesis (Th. M.)--Dallas Theological Seminary, 2006. / Includes bibliographical references (leaves [51]-54).

Thesis (Th. M.)--Dallas Theological Seminary, 2006. / Includes bibliographical references (leaves [51]-54).

Thesis (Ph. D.)--Antioch University New England, 2008. / "A dissertation in partial fulfillment of the requirements for the degree of Doctor of Philosophy Environmental Studies at the Antioch University New England June 2008"--The title page. Title from PDF t.p. (viewed July 29, 2008). Advisor: Dr. Beth A. Kaplin. Keywords: Q-methodology, protected areas, biodiversity conservation, policy sciences. Includes bibliographical references (p. 161-168).

Thesis (Ph. D.)--Columbia University. / Vita. Reprinted from Studies in history, economics and public law, ed. by the Faculty of political science of Columbia university, vol. XXIX, no. 1. Includes bibliographical references.