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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Chemical cues affecting susceptibility of gorgonian corals to fungal infection

Hicks, Melissa Kathryn. January 2005 (has links)
Thesis (M. S.)--Biology, Georgia Institute of Technology, 2006. / Kubanek, Julia, Committee Chair ; Hay, Mark, Committee Member ; Loeffler, Frank, Committee Member.
32

Ecological studies of neritic phytoplankton of Southern California seasonal variations, associations and responses to temperature elevations /

Briand, Frédéric Jean-Paul, January 1974 (has links)
Thesis (Ph. D.)--University of California, Irvine, 1974. / Vita. Includes bibliographical references (leaves 129-132).
33

The distribution of the amphipod Gammarus pseudolimnaeus Bousfield as influenced by oxygen concentration, substratum, and current

Rees, Colin Pritchard, January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
34

Snail grazing effects on the composition and metabolism of benthic diatom communities and subsequent effects on fish growth /

Connor, Michael Stewart. January 1980 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 1980. / Supervised by John M. Teal. Vita. Includes bibliographical references.
35

Development and application of ecosystem models to support fishery sustainability : a case study for the Gulf of Alaska /

Gaichas, Sarah K. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 281-297).
36

Biomass spectra in Narragansett Bay from phytoplankton to fish /

Longval, Brooke A. January 2009 (has links)
Thesis (Ph.D.)--University of Rhode Island, 2009. / Includes bibliographical references (leaves 185-199).
37

An assessment of statistical methodologies used in the analysis of marine community data /

Ellis, Rodney Neal. January 2005 (has links) (PDF)
Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.
38

The ecology of a tidal pool at St. Andrews, Fife

Irvine, David Edward Guthrie January 1954 (has links)
Literature dealing with rook pools is scanty, and as a rule they have been studied either very generally or over a rather short period of time. During the course of the present work a single pool, 3.7 x 1.5 m., just below high water neap tide level on the St. Andrews shore, has been studied in detail from June 1950 to March 1954, in an endeavour to correlate changes in flora and fauna with variations in environmental conditions. The location and topography, periods of exposure, illumination, temperature, hydrogen ion concentration and salinity have been measured to a greater or lesser extent, and observations made or estimations formed of the probable importance of desiccation, wave action, dissolved oxygen concentration, inorganic substances other than chlorides in solution, organic matter present, and biotic factors. It has been shown that conditions vary very considerably from one part of the pool to another at any one time, and in particular parts at different times of the day or seasons of the year, and that various factors are so closely linked in their effects that they cannot usefully be considered independently. An ecological classification of the pool vegetation has been evolved which emphasises the parallel between the range of conditions (and hence of types of algal growth) within the pool and on the shore in general. The high incidence of epiphytism is considered in some detail, and its importance and effects in the case of both host and epiphyte assessed. Healthy plants seem less liable to epiphytic settlement than unhealthy specimens; species which are generally epiphytic do not as a rule thrive in other situations, and vice versa; the principal danger to the actual life of the host plant seems to lie in the greater liability to removal, due to increased resistance to wave force. Comparison of the life cycles within the pool of the various algal species has shown the prevalence of vegetative reproduction, including regeneration, from perennial basal parts, amongst the community-forming plants of the pool. The flora (80 species identified, including 24 unpublished St .Andrews records) and the fauna (98 identified, including 35 unpublished) are listed, with notes on times of occurrence, frequency, habit, size, reproduction end other noteworthy features, and additional notes are provided amplifying these details for species of particular nomenclatural, taxonomic or ecological interests. The relations between plants and animals are considered in further detail, with reference to quantitative samples of the flora and fauna taken from time to time. Faunal populations are shown to vary amongst different types of vegetation, and in some oases to be closely dependent on the presence of particular algal species. The vital importance of atmospheric conditions during the prolonged exposure of the pool at times of poor neap tides is illustrated and discussed. High water neap tide level is considered to be highly critical for the flora and fauna of rook pools. The seasonal cycle of vegetation and the faunal population of the pool are shown to have varied somewhat from year to year, and an attempt is made to correlate these changes with the correspondingly exceptional meteorological conditions. Species frequent in neighbouring pools but rare or absent in the case of this particular pool are instanced and discussed. Temperature fluctuations are considered to be probably the most important limiting factor for the majority of the algae concerned. The generally stunted nature of the vegetation and frequently reduced cell size are attributed primarily to the shallowness of the pool, exposure to violent wave action, (and adverse conditions during the normal growing season. Browsing animals constitute a serious menace to spores, sporelings and minute plants, but are probably rarely lethal where the larger plants are concerned. The dynamic nature of the relationships of the population to its environment is stressed. Three main trends of change are shown to exist in the pool: the complex succession from bare rock to semi-permanent covering by a dense algal community, the catastrophic effects of neap tide conditions, especially during spring and early summer, and the more or less regular seasonal succession of vegetative changes. Particular stress is placed on the importance of long-term observations in assessing the distribution of population within this type of habitat.
39

The autecology of Pylaiella littoralis (L.) Kjellm. at St. Andrews, Scotland with additional information on the life cycle of Pylaiella rupincola (Aresh.) Kylin

Russell, George January 1959 (has links)
(1) The nomenclature and position of Pylaiella littoralis in classifications of the Phaeophyta are, briefly described, the value of the species as a subject for autecological investigation is assessed and the aims of the investigation stated, (ii) The distribution of P. littoralis in (a) the northern hemisphere and (b) on the British coasts is reviewed and the species is found to be both common and widespread in all areas. (iii) The morphology of P. littoralis is briefly described, the chief features being the cell wall, cell contents, cell dimensions, cable rolling, sporangia (structures and dimensions) and growth areas. (iv) The life cycle of P. littoralla is reviewed and the findings of other workers compared with those for the species at St. Andresws. The life cycle of P. littoralis at St. Andrews is deduced from field observations, studies in culture and cytological evidence and hot found to be very different from the pattern typical of the filamentous Ectocarpaceae. (v) The stages of early growth from the zoospore to the age of six weeks are described on the basis of observations made on the species growing in culture. (vi) The distribution of P. littpralis at St. Andrews is found to fall into several natural communities, These are (1) a permanent lithophytic community growing on rock ridges at about mean tide level, (2) a community growing on boulders at the foot of a north-facing cliff, (3) an epiphytic community found in summer and autumn on open parts of the shore and in winter and spring in pools at, or slightly below, high water of neap tide's, (4) a community growing on mud, stones or Fucus ceranoides within the confines of the harbour at St. Andrews and lastly, (5) a salt marsh community at the estuary of the River Eden some three miles to the north of St. Andrews. The different species of algae and, to a lesser extent, of fauna associated with the Pylalella in these communities are described. The more important environmental conditions are also described and, where possible, measured. Additional information when relevant to the species in any of the communities is given in the form of short notes. (vii) The differehoes between the Pylaiella plants from the three main communities (i.e. lithophytic, epiphytic and harbour) are described from morphological features and from the results of transplant experiments in the field and in culture. (viii) The subspecific taxonomy of littoralia is reviewed and the plants from the three main communities at St. Andrews identified. (ix) The life cycle, morphology and ecology of Pylaiella rupincola is reviewed and the results of personal investigation of the species given, the material used in the investigation having been sent from Kristineberg, Sweden. (x) The two main features arising from the present study are discuissed. These are (1) the close relationship between distribution, environmental conditions, and life cycle in separate from (xi) The various conclusions reached from the investigation are given; of these the most important are:- (1) The gametophyte generation of is produced by, germination of the zoospores released from unilocular sporangia. This generation is small in size, seasonal (spring) in distribution, and, relative to the sporophyte, of uncommon occurrence at St. Andrews. (2) Environmental conditions affect the growth, fertility and the types of sporangia borne by P. littoralis but changes in the environmental conditions are not accompanied by morphological alteration and are generally detrimental to the species, (3) The ecological races of littoralis cannot be described in the nomenclature of orthodox taxonomy. (4) As a result of the investigation carried out on P. rupincola it is concluded that it should no longer be separated from P. littoralis on the grounds suggested by Kylin (1937).
40

Effects of changes in temperature, salinity and undefined properties of sea water on the respiration of Euphausia pacifica Hansen (crustacea) in relation to the species' ecology

Gilfillan, Edward Smith January 1970 (has links)
Temperature, salinity, and other, undefined properties of sea water have been suggested as factors acting to limit the distribution of planktonic organisms through the stresses they impose. The aim of this study was to examine experimentally the effects of changes in these properties on the respiration of Euphausia pacifica Hansen. Both immediate and long term effects of changes in these properties were examined. Assessments of the immediate effects of changes in temperature and salinity on the animals' respiratory rate demonstrated that a sharp reduction in respiratory rate could be used as an indication of stress. The results of these same experiments showed that as the values of temperature and salinity approached the limits of tolerance, the effects of stresses from them interact. The long term effects of changes in temperature and salinity were investigated by determining the limits of these factors that were tolerable to specimens from areas in which the characteristic temperatures and salinities of the water were different. Specimens from the water having the greatest range of values of temperature and salinity (coastal) possessed the greatest tolerance to changes in temperature and salinity; specimens from water having the least range of temperature and salinity (oceanic) had the least tolerance. The tolerances to changes in temperature and salinity observed in these experiments indicated that the distribution of E. pacifica in British Columbia coastal waters was not likely to be influenced by changes in temperature and salinity except near the surface, where the salinity may become low and the temperature high or very low. Experiments taking advantage of the interaction between the effects of temperature and salinity were used to establish that other properties of sea water, while undefined, could impose stress on adult E. pacifica. At the same time a method of assessing the effects of changes in undefined properties between sea waters through a comparison of respiratory rates obtained under standard conditions was developed. The results of experiments in which changes in undefined properties of sea waters collected at two depths in each of two locations were examined indicate that these properties appear to be a function of the origin of the particular water. They also indicate that differences between waters in these properties did not affect the distribution of E. pacifica within either of the two areas investigated, namely the Strait of Georgia and Indian Arm. The results did indicate, however, that populations of E. pacifica were present in each of these areas in which inverse reactions to the same set of undefined properties existed. Presumably these result from persistent differences in undefined properties between the waters resident in each of the two areas. / Science, Faculty of / Zoology, Department of / Graduate

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