Thesis (M.S.)--University of Toledo, 2006. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science Degree in Biology (Ecology-track)." Bibliography: leaves 26-34.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (levaes 151-161). Also available via the Internet.

Thesis (M.S.) in Wildlife Ecology--University of Maine, 2004. / Includes vita. Includes bibliographical references (leaves 65-76).

Thesis (Ph. D. (Zoology & Entomology))--Rhodes University, 2004.

Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 78-92).

Thesis (Ph.D.)--Aberdeen University, 2008. / Title from web page (viewed on Apr. 20, 2009). Includes bibliographical references.

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The effect of the invasive macrophyte Myriophyllum spicatum L. on native macrophyte diversity was studied across 21 lakes at small (1 quadrat) and large (18 quadrats) scales and in mesocosms. No relationship was observed between M. spicatum and native richness at either spatial scale, or native evenness at small scales; however, at large scales native evenness was negatively correlated with the cover of M. spicatum in lakes. This suggests that M. spicatum can grow in lakes with other dominant species, contrary to predictions that invasive species will outcompete other dominant species. While macrophyte communities were mainly distinguished by environmental and spatial variables, M. spicatum was a significant predictor of the remaining variation in community composition. Within lakes M. spicatum occurred in deep water apart from other species; however, competition studies in mesocosms did not find sufficient evidence that this isolation was due to superior competitiveness.

This study has shown that season, salinity, temperature and intertidal height all affect the rate up calcium uptake by mussels. For summer-adapted mussels, calcium uptake was found to be temperature dependent over the range of acute temperatures measured (1°-23°C). When subjected to a range of salinities over a three week period, summer-adapted mussels showed calcium-uptake rates which were salinity dependent from 25%-75% SW, and which did not show any increase in uptake rate in salinities greater than 75% SW. For winter-adapted mussels, calcium uptake was temperature independent over a temperature range from 5°-l7°C. At higher and lower temperatures, uptake was reduced. When subjected to a range of salinities over a three-week period, winter-adapted mussels were also unable to compensate for the lower concentration of calcium in the seawater, and did not show any increase in the uptake rate in salinities greater than 75% SW. It was found that high and low intertidal mussels had different calcium uptake rates, and that transplantation could alter the uptake rate of transplanted mussels to the uptake rate of untransplanted controls. In the intertidal zone a gradient of shell size was found, which could be associated with the change in uptake range over the intertidal range. Differences in immersion time between the two. sites could not explain all of the differences in uptake rate, but high intertidal mussels were found to have less total dry weight of soft parts than low mussels, and correcting for this difference accounted for the the remainder of the difference in calcium-uptake rate between the two sites. The soft parts of the mussel were found to become saturated with ⁴⁵Ca after four hours, while the shell accumulated calcium for the duration of the experiment. The mantle and gill tissue held the same amount of calcium when corrected for differences in weight, while the viscera held a greater pool of calcium. Accounting for real increases in the amount of calcium accumulated by the shell showed that the uptake rates reported in this study are about 59% of the absolute uptake rates. / Science, Faculty of / Zoology, Department of / Graduate

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