Appropriate sampling and experimental programs resulted in a qualitative and quantitative assessment of seaweed litter biomasses, decomposition rates and concomitant changes in nitrogen content; detritus biomass and decomposition rates; and faunal distribution patterns for the significant species within a successional seaweed community in the Strait of Georgia, British Columbia, Canada. A simulation model incorporating suitable data obtained from these sampling and experimental programs facilitated prediction of detritus formation rates, biomass, nitrogen content and the seasonal availability of detritus as a food resource for fauna. Soluble matter release rates from decomposing seaweed litter and its nitrogen content were also determined. Of the ca 43 taxa identified within the seaweed litter collections, Fucus distichvs L. (41%), Irldaea cordata (Turner) Bory (26%), Nereocystis 1uetkeana (Mertens) Postels and Ruprecht (27%), and Laminaria (4%) (L. saccharina (L.) Lamouroux and L. groenlandica Rosenvinge) accounted for more than 97% of total litter deposition. The mean peak summer biomass of all litter was ca 5 g ash-free dry weight (AFDW)/m² with this figure approaching zero during January and February. Litter distribution was patchy and there was sufficient evidence to conclude that most litter was retained, and underwent decomposition, in the immediate vicinity of its place of deposition. Litter decomposition experiments performed on the 10 most significant contributors to seaweed community structure indicated that decomposition of seaweed litter occurs rapidly compared to vascular plant litter. The time required for seaweed litter to disappear from 2 mm mesh litter bags ranged from six days, for the lamina of Nereocystis luetkeana, to ca 70 days, for Fucus distichus. Some similarity in decomposition rates was observed amongst species displaying taxonomic and/or morphologic affinities. Assessment of nitrogen content of decomposing seaweed litter revealed that nine of the 10 species assayed lost nitrogen less rapidly than total litter biomass. As determined by assaying microbial consumption of particulate material, the time required for detritus (particle size < 1 mm, dry) to fully decompose was short. Of the 10 species tested, Iridaea cordata detritus decomposed most rapidly at a rate of 5.7% per day while rates for Gigartina papillata (C. Agardh) J. Agardh, Laminaria groenlandica, Laminaria saccharina and Nereocystis luetkeana ranged from 2-4% per day. Data for the remaining species were less conclusive although all decomposed at rates less than one percent per day. Variation in specific decomposition rates was shown to be correlated with the structural composition of the detritus. Those species with a relatively small percentage of crude fibre as a component of their particulate fraction decomposed more rapidly than those species with a higher percentage of crude fibre. For the two most rapidly decomposing species, Iridaea cordata and Nereocystis luetkeana, a trend toward a more rapid decomposition rate as mean particle size decreased was evident. Natural detritus (particle size < 2 mm, wet) biomass accumulation within the study site peaked at ca 1.4 g AFDW/m² during the latter half of August 19 76. This value represents 1-5% of the quantity of detritus predicted to have been formed from seaweed litter alone and a lesser percentage of the total quantity of seaweed detritus formed. Exportation out of the seaweed zone is believed to be responsible for this discrepancy. The predicted rates of detritus formation and soluble matter release from decomposing seaweed litter peaked at ca 0.6 and 0.5 g AFDW/m²per day, respectively, in early September 1976 from a low near zero in February. In total, ca 56% of litter biomass formed detritus, the remainder being released as soluble matter. The mean nitrogen contents of the detritus formed and the soluble matter released were 2.48 ± 0.03% and 1.36 ± 0.03% of their dry weights, respectively. The annual contribution of seaweed litter biomass via detritus and soluble matter to local coastal waters is estimated to be in the range of 70-85 g C/m². Detritus formed from seaweed litter was determined to have a C:N ratio of 10-13:1, rendering it suitably nutritious for utilization by fauna as a food resource, however it could not be shown conclusively that the coincidence, en masse, of specific fauna and maximum detritus availability was a response to the availability of detritus as a food resource. The possibility of such a correlation is discussed with reference to two species of caprellids, Caprella alaskana Mayer and Metacaprella anomala Mayer, and the benthic gastropod Lacuna marmorata Dall. / Science, Faculty of / Botany, Department of / Graduate

Bibliography: pages 215-244. / Clostridium acetobutylicum P262 is an endospore forming Gram-positive obligate anaerobe which has been used for the industrial production of acetone and butanol. Strains of C. acetobutylicum have been reported to exhibit some activity towards cellulosic and hemicellulosic substrates. The aim of this thesis was to establish a genebank of C. acetobutylicum P262 DNA in Escherichia coli and to isolate and characterise genes encoding enzymes which show activity towards hemicellulose and cellulose.

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Landfill leachates are often treated on-site before disposal to municipal wastewater treatment plants, although variations in leachate composition and organic loading continue to have negative impacts on downstream treatment processes.  Leachate samples were collected from four landfills both before and after on-site treatment to evaluate the extent of biological treatment. The samples vary in age, location, and on-site treatment processes.  Size fractionation utilizing microfiltration (MF) and ultrafiltration (UF) was conducted in conjunction with TOC, nitrogen species, and UV254 absorbance analysis to determine the characteristics of organic constituents present in landfill leachate.  The size fraction less than 1thousand Daltons (1 kDa) was responsible for a predominant portion of the organic fraction of the landfill leachates studied.  Humic substances are refractory components present in landfill leachates that are resistant to biological treatment and responsible for a portion of the UV quenching ability of leachates.  Humic substances were also fractionated to humic acid (HA), fulvic acid (FA), and hydrophilic (Hpi) components before being subjected to size fractionation to determine UV254 absorbance and organic fractions.  Particle size and hydrophobic-hydrophilic fractionation were conducted in series to evaluate the potential for membrane treatment after biological treatment as a cost effective alternative to reverse osmosis processes currently used to decrease the organic fractions present in landfill leachate.  The organic nitrogen fraction was predominately in the hydrophilic fraction smaller than 1 kDa. / Master of Science

Conventional landfills are built to dispose of the increasing amount of municipal solid waste (MSW) generated each year. A relatively new type of landfill, called a bioreactor landfill, is designed to optimize the biodegradation of the contained waste to stabilized products. Landfills with stabilized waste pose little threat to the environment from ozone depleting gases and groundwater contamination. Limited research has been done to determine the importance of biodegradation enhancement techniques and the analytical methods that are used to characterize waste stability. The purpose of this research was to determine the effectiveness of several biodegradation enhancements and to evaluate the analytical methods which predict landfill stability. In the first part of this study leachate recirculation, and moisture and temperature management were found to significantly affect the biodegradation of MSW. Leachate recirculation, increased moisture, and higher temperatures increased the first order degradation rates of cellulose and volatile solids. Of the three enhancements, temperature was shown to have the biggest impact on the biodegradation of waste, but sufficient moisture is critical for degradation. Plastic material was also shown to significantly impact the measurements for volatile solids and lignin, which is important if these measurements are used to establish waste stability. In the second part of the study the analytical methods used to characterize waste were evaluated to determine if relationships existed between the methods and which methods were the best predictors of waste stability. Volatile solids and cellulose were found to be the best parameters to monitor waste in landfills. These parameters correlate well with each other, age of the waste, and other parameters. Volatile solids and cellulose are also relatively easy to determine, quick, and show little variation. / Master of Science

A facultative anaerobic bacterium that rapidly degrades cyanuric acid (CA) was isolated from sediment of a stream that received industrial waste water effluent. CA decomposition was measured throughout the growth cycle by using a High Performance Liquid Chromatography assay while also measuring the concomitant production of ammonia. This bacterium used CA or cysteine as a major, if not sole, carbon and energy source under anaerobic, but not aerobic conditions in a defined medium. The cell yield was greatly enhanced by the simultaneous presence of cysteine and CA in the medium. Cysteine was preferentially used rather than CA early in the growth cycle, but all the CA was used without an apparent lag after the cysteine was metabolized. Atrazine was also degraded by this bacterium under anaerobic conditions in a defined medium. / Master of Science