Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Includes bibliographical references.

Gradients of physical disturbance are central to theories of community organization yet rarely are studies performed in which physical factors are experimentally manipulated. Pothole tidepool algal communities exhibit distinct zonation patterns from top to bottom that result from scouring by rocks and other debris in the pools. Scouring is easily manipulated by removing or adding rocks to tidepools. Thus, the gradient of physical disturbance potentially causing community patterns can be manipulated to test theories of community organization. I documented the distribution pattern of algae inhabiting pothole tidepools and measured a number of physical factors which were hypothesized to be responsible for the observed zonation patterns. Then, I experimentally evaluated the roles of physical disturbance, herbivory, and competition in these tidepool communities. I found that scouring by rocks was primarily responsible for the observed zonation patterns in pothole tidepools. However, not all pools are potholes. Evaluation of the physical properties effecting the cobble-retaining ability of tidepools enabled prediction over a broad geographic range of pools likely to have cobbles and thus show typical pothole algal zonation patterns. Coralline algae (Rhodophyta, Corallinaceae) are a dominant feature of tidepools as well as many low intertidal and subtidal habitats. I evaluated the relative resistance of coralline algae (both articulated and crustose forms) and other common tidepool algae to scouring by rocks. Coralline crusts were highly resistant to scouring while articulated coralline algae are very susceptible to scouring. Erect fleshy algal species showed intermediate resistance to scouring. This corresponds well to observed algal zonation patterns in intertidal potholes. Based on this information, I proposed that wave-induced scouring may have been the selective force for the initial incorporation of calcium carbonate into algal thalli. / Graduation date: 1992

Experiments were carried out in fall and winter, 1990 and spring and summer, 1991 , to determine growth and mortality of juvenile Pacific oysters {Crassostrea gigas) in effluent from cultured coho salmon {Oncorhynchus kisutch) , and effluent from salmon in which the red macroalga Palmaria mollis was cultured. Ambient sea water from Yaquina Bay was used as a control. Juvenile Manila clams {Tapes japonica) were also tested in summer, to compare the growth response of clams with that of Pacific oysters. Measured growth parameters included: increase in mean individual live weight, specific growth rate (% increase of mean live weight per day) and mean individual organic (ash-free) weight. Temperature, chlorophyll a, phaeopigment, carbon and nitrogen concentrations and C/N ratio for all treatments were also recorded during spring and summer, 1991. The oysters grew significantly faster in effluent from salmon and salmon conditioned by macroalgae than in the control during the Fall Experiment (September 7- 0ctober 31, 1990). Mean water temperature was 13-16°C. Growth rates were significantly greater in oysters cultured in salmon effluent than in the control during the Winter Experiment (December 7, 1990-February 15, 1991). However, growth was very poor due to low water temperatures (7-10°C). Growth of oysters was significantly greater in the control than in effluent from salmon and salmon conditioned by macrolagae in the Spring Experiment (March 7-May 24, 1991). Mean water temperature was 12°C. In the Summer Experiments, (June 3-July 4 and July 19-August 17, 1991) growth of oysters was more rapid in treatments with macroalgae as compared to treatments without macroalgae Comparative experiments with juvenile Manila clams gave similar results. Percentage mortality for both oysters and clams ranged from 0 to 5% and was highest during winter and lowest during summer. Mean chlorophyll values ranged from 1 μg/1 in spring, 1991 to 11 μg/1 summer, 1991. / Graduation date: 1992

Tez (Doktora) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Su Ürünleri Temel Bilimleri, 2009. / Kaynakça var.

No description available.

Graduation date: 1987

I investigated the ecological functions of halogenated secondary metabolites from the red alga Asparagopsis armata, their localisation in specialised cells and also their cost of production. A. armata produces large amounts of halogenated metabolites ( &lt 20 ??g / mg dry weight) that are sequestered in gland cells, as was demonstrated with light, epifluorescence and transmission electron microscopy. Cellular structures were identified that likely assist the release of metabolites from the gland cells to the algal surface. The halogenated metabolites of A. armata have multiple ecological roles, functioning as both inhibitors of bacterial fouling and as herbivore deterrents. Their activity against bacteria and herbivores was measured by a novel test in which the metabolites were manipulated in A. armata by omitting bromide ions from the culture media. This technique prevented the production of halogenated metabolites, but did not impact on other aspects of algal biology. Algae lacking halogenated metabolites (bromide [-] algae) had higher densities of epiphytic bacteria than those that continued to produce metabolites (bromide [+] algae). Bioassays with pure compounds against individual bacterial isolates further supported an inhibitory role for the halogenated metabolites against epiphytic bacteria, and also indicated an affect on bacterial community structure as well as abundance. Bromide (+) A. armata produced halogenated metabolites that also deterred feeding by two herbivores (an amphipod and an abalone), but not a third (an opisthobranch mollusc). A novel outcome from these feeding assays was the demonstration of a relationship between herbivore size and consumption of the chemically defended A. armata by the abalone Haliotis rubra. In addition to the fitness benefits gained from chemical defence, there were also costs for allocating resources to secondary metabolites. These costs were only detected under limiting light resources, consistent with predictions of the plant defence models. The integration of chemical analyses and cellular measures of chemical defence proved essential in elucidating resource allocation to chemical defence in the filamentous stage of A. armata. This thesis highlights that the simple relationships between growth and defence in filamentous algae can provide an excellent model for studies of the ecology and evolution of chemical defences in marine algae.

Typescript (photocopy) / vii, 228 leaves, [43] leaves of plates : ill. ; 31 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1981

Thesis (M.S.)--University of North Carolina Wilmington, 2008. / Title from PDF title page (viewed May 27, 2009) Includes bibliographical references (p. 132-135)

Thesis (M.E.S.)--Evergreen State College, 2008. / "December, 2008." Title from title screen (viewed 4/8/2010). Includes bibliographical references (leaves 22-28).