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Species separation of character-poor Asterionella, an abundant Great Lakes diatom, is difficult to accomplish by visual inspection alone. Asterionella shape, which is an ontogenic property, was studied quantitatively including novel application of fuzzy measure theory. To quantify shape, Fourier coefficients were calculated from arc lengths and tangent angles around the valve periphery of 96 Asterionella from Lakes Superior, Huron, and Michigan. Polar Fourier coefficients resulted from orthogonal polynomial regression of F*t =a0+n=1 NAn cos nt+an , where a0 is the zeroth Fourier coefficient, An is the nth amplitude, and alphan is the nth phase angle for N coefficients. One-hundred x,y coordinates were used to calculate 22 shape coefficients to get a best fit closed curve in a least squares sense. Standardized PCA of mean-corrected, square root transformed amplitudes and visual inspection produced seven Asterionella shape groups. Classification integration and fuzzy measures were used to determine degree of shape group overlap and degree that specimens belonged to their assigned shape group. Fuzzy measures were based on morphometry of head pole, foot pole, and mid-valve widths or a combination and scaled and ordered on the interval [0, 1]. Sugeno's or the fuzzy integral, E= Hx&j0; g• , where E is the evaluation of h(x) (partial evidence) and g• (importance or possibility measure), was used. Partial evidence was fuzzy average overlap. Degree of shape group membership was evaluated as degree of certainty (partial evidence) and Sugeno's measure (importance measure). Complete overlap or specimen inclusion was equal to one, complete lack of overlap or specimen exclusion was equal to zero, and the cross-over point was 0.5. Two exceptions, shape groups II--III and shape groups IV--V at E = 0.6 exhibited overlap. Two specimen assignments were slightly questionable at E = 0.49 and E = 0.57 for shape groups II and VI, respectively. All other specimen assignments were E ≥ 0.6. Most northern Great Lakes Asterionella were members of shape groups I--III. Lake Michigan Asterionella were mostly in shape groups IV--VII. Reproductive isolation is supported by additional evidence with regard to Great Lakes water movement patterns and isozyme analysis of Lakes Superior and Michigan Asterionella.

Hypotheses of intralacustrine speciation are tested for phenotypically divergent populations of lake trout (Salvelinus namaycush) with molecular genetic, morphometric, and osteological investigations. Three recognizable forms of Salvelinus namaycush inhabit Lake Superior. The different phenotypes are recognized based on facial and skull characteristics, fat content, and temporal and spatial reproductive characteristics. The lean inhabits inshore areas less than 70 meters deep, the siscowet inhabits waters deeper than 80 meters, and the humper lives over isolated shoals surrounded by water greater than 100 meters. Lean lake trout are found in virtually every deep lake in northern North America, in contrast to the siscowet and humper that are endemic to Lake Superior. Differences were thought to be ecophenotypic but controlled hatchery experiments demonstrated a genetic component. Differences in the morphology of the opercle and supraethmoid bones between siscowet-humper and lean phenotypes are 90% consistent and provide additional support for a genetic component to phenotypic differentiation. I used mitochondrial DNA restriction fragment length polymorphisms and morphometric measurements employing principal components to analyze the relative contributions of environment and genotype to phenotypic divergence. Biochemical genetic analysis of mitochondrial DNA indicates the presence of a hypervariable genome. No differences among the mtDNA genotypes justify species level discrimination among lean, siscowet, and humper phenotypes. Levels of sequence divergence ranged from 0.01% to 1.7% between phenotypes, comparable to within-species levels of divergence for other salmonids. Widely shared mtDNA clonal haplotypes suggest that there has been gene flow among the three forms in Lake Superior. The failure of morphometrics of wild leans and siscowets to corroborate the discrimination observed in the hatchery puts in question the breadth of the genetic basis for the morphometric characters of wild lake trout. The humper phenotype showed a mosaic of molecular-genetic, morphological, osteological, and life history differences that support a hypothesis of hybrid origin in post-glacial Lake Superior. Subtle genetic differences are probably limited to regulatory or modifier genes in the nuclear genome that govern metabolism and growth. Divergence in ecological adaptations with partial reproductive isolation by differences in time and place of spawning is suggested as the probable precedent to intralacustrine speciation.

This dissertation analyzes cross-cultural encounters between indigenous and intrusive societies along Lake Michigan's eastern and southern shores. The primary focus is on the St. Joseph River valley, which was the principal fur-trade portage from the Great Lakes to the Mississippi. The French and British vied for control of this river valley; the Potawatomi and French became allies. An analysis of the St. Joseph Baptismal Register, kept by the Jesuits from 1720 to 1773, shows the evolution of a metis society. Intermarriage between French and Native Americans cemented their alliance and fostered demographic stability. The metis served as intercultural mediators. They kept Catholicism alive despite Jesuit demise and helped negotiate treaty provisions that later protected many Potawatomi from removal on account of their religion. By the nineteenth century, the Potawatomi were a prosperous agricultural society. The first American settlers, primarily blacks, Irish, and Germans, settled near the Potawatomi. But diversity brought disunity. The midwestern frontier became fertile ground for conservative movements that resisted social change. The increasing Catholic presence--an academy, university, and convent--brought a nativist backlash. Invisibility became conducive to survival. Midwestern history has been written to emphasize the role that eastern pioneer families played in settling this frontier. Farmers displaced Potawatomi, black robes, and metis as the settlers of the St. Joseph River valley. By telling a different story--a story about a time and place where the sequence of events has gone unexamined--this dissertation exposes the multiplicity of narrative viewpoints and their involvement in larger narratives about ethnicity and culture, autonomy and interdependence, and maleness and femaleness.

Great Lakes Basin resource management is pursued through a complex institutional ecosystem; an interrelated hierarchy of U.S. and Canadian political jurisdictions and a series of regional, multi-jurisdictional institutions recognizing hydrologic as well as political boundaries. The evolution of this institutional ecosystem has been accompanied by a long-standing yet poorly articulated sense of dissatisfaction within the region. It is further hampered by inadequate understanding of past and present regional institutions and their respective roles. To address this failing, a systematic review of past and present institutional arrangements for basin management--in the Great Lakes region and elsewhere--was undertaken to identify and analyze management strategies and organizational characteristics that hold promise for Great Lakes management. The corresponding goal is to encourage orderly and informed evolution of the institutional ecosystem and advance the efficiency and effectiveness of regional resource management efforts. A multi-faceted approach involving literature review, case study analyses, personal interviews, survey questionnaires and institutional observation was undertaken to (1) provide a binational perspective on regional resource management approaches in the Great Lakes Basin and elsewhere; (2) identify organizational characteristics and management strategies potentially applicable to Great Lakes institutional arrangements; (3) explore linkages within the institutional ecosystem and associated strengths and weaknesses; (4) develop guidelines, parameters and organizational criteria as benchmarks for assessing institutional adequacy; and (5) based on that determination, design alternate institutional arrangements that might be incorporated into, replace or otherwise augment existing arrangements to enhance the orderly and informed evolution of the Great Lakes institutional ecosystem. The investigation yielded four alternate scenarios for strengthening the Great Lakes management effort: preserving the status quo; incremental change to existing institutions; substantive revision of existing arrangements; and dramatic, single-step revision entailing outright elimination of present arrangements in favor of a new and significantly different one. Each is evaluated in light of political realities and operational constraints, with a recommendation for staged implementation of the second and third scenarios. Specific policy recommendations are applied to the existing institutional ecosystem and, in particular, its regional components.

This research is an examination of the dynamics of Great Lakes coastal wetland area changes caused by long term water level fluctuations. Six hypotheses are examined using wetland area data obtained from interpretation of historical aerial photographs of Great Lakes wetland sites at different water levels. The three Multi-Class hypotheses concerned the relations between water level and wetland area changes in five wetland classes and Upland. The Multi-Class Response Hypothesis characterized these relations as interclass transfers and base area changes. Area transfer rates among the wetland classes were estimated. In an examination of the Lag Response Hypothesis, regression analysis with moving average water levels showed that wetland class response time varied from 5 to 22 years. Examination of the Nearest Hydrologic Neighbor Hypothesis showed that St. Marys River wetland class displacements were not always restricted to classes one step more or less flood tolerant. The three Emergent wetland hypotheses concerned Emergent wetland area response to water level change at sites throughout the Great Lakes. Confirmation of the Aggregate Response Hypothesis showed that Emergent wetland responses throughout the Great Lakes Basin could be characterized by a single model. Confirmation of the Lag Response Hypothesis for Emergent Wetlands showed that Emergent wetlands varied in their response rates to water level changes; response could be completed within one year or take as long as 15 years. Confirmation of the Coastal Profile Hypothesis showed that the causal mechanism of Emergent wetland area response can be modeled using a combined planar and concave-up power curve of the onshore-offshore profile. The Aggregate Response model can be used as a basis for more accurate estimates of wetland losses since pre-settlement times, and for modeling Emergent wetland changes on a basinwide scale under current regulatory and climatic conditions. Accurately predicting the effects of altered level regulation plans or global warming will require use of the Coastal Profile approach and extensive information on interclass transfer rates at the upper ends of offshore-onshore profiles.

Uncertainties surrounding the nature of the mixing mechanisms governing upper ocean thermal structure still exist today. Progress in resolving these equations has been largely confined to the open ocean and whether these efforts are applicable to inland seas is yet uncertain. Hence, approximately 200,000 observations of water temperature were assembled from Lakes Erie and Michigan and were used in conjunction with four one-dimensional mixed layer models to evaluate model applicability to tideless seas and to aid in interpretation of lake physics. The four models were: Denman (1973) (KLD), Garwood (1977) (RWG), McCormick and Scavia (1981) (K) and Thompson (1976) (RT). The mixed layer depth, h, is the depth over which surface generated turbulence is of sufficient intensity to penetrate buoyant surface waters and uniformly mix the entire layer. The entrainment rate, dh/dt, is scaled in these models according to either U(,*), the friction velocity, or (DELTA)V, the velocity jump across the mixed layer base, or a combination of both, i.e. RWG. The results showed that any one of the models can be calibrated so as to give reasonable and similar estimates of surface water temperatures (from hourly to monthly time scales) as measured in terms of Root Mean Squared Error (RMSE). In Lake Erie, 1(DEGREES)C RMSEs were typical for upper lake thermal structure while the Michigan RMSEs were somewhat larger. The models showed their greatest differences on shorter time scales. Namely, the K model failed to resolve deepening of h during a late spring storm on Lake Erie while the other models tracked the deepening fairly well. Therefore, when diurnal physical processes are of interest the best model is then the one that is most faithful in reproducing not only observed temperatures, but also the correct mixed layer depths and the proper amount of entrainment energy. In this study two of the models, RT and RWG, which use the (DELTA)V entrainment scaling, not only tracked temperatures and h closely but they too, in general, showed the best agreement in matching the energy levels associated with entrainment as estimated from spectral analyses of model output and data.

This dissertation developed, implemented, and verified a variably saturated flow model which incorporates the effects of wave activity and transient changes in lake level on lake-aquifer interactions using the radiation stress approach to calculate mean water levels at the beach. This research was based on a two dimensional numerical model in the vertical plane based on the Galerkin finite element method. Simulations using this model confirmed the hypothesis that storm events on Lake Michigan are of sufficient magnitude to drive lake water in adjacent beaches against regional hydraulic gradients. Analysis showed that the relative magnitude of lake level changes and wave action on Lake Michigan make wave action the dominant source of lake water input into the adjacent beaches. Variations of hydraulic conductivity and anisotropy ratios affected the amount lake water input and flow patterns in the beach most strongly. Relative beach location on the lake also had a significant effect. In June 1996, innovative multi-level sampling arrays were designed and installed in the beach under which a plume of chlorinated solvents is discharging to Lake Michigan. These were monitored from June to December 1996. Sampling results suggested that lake water infiltrates and/or has an influence to a depth of at least 4 meters under the beach surface and that vinyl chloride and methane may be selectively oxidized in shallow regions of the aquifer as those regions become less reduced in response to lake activity. This dissertation also developed and implemented a contaminant fate and transport model to investigated the effect of lake-aquifer interactions on the discharge of trichloroethene, dichloroethene, and vinyl chloride to the Great Lakes. This model incorporated both oxidative processes in the presence of oxygen and methane as well as reductive dechlorination of the chlorinated ethenes in the absence of oxygen. The model has been applied to tile National Priority List site that is the subject of the field work described above. Simulations support the hypothesis that lake-aquifer interactions affect the magnitude and location of chlorinated ethenes discharges to Lake Michigan at this site. The field sampling and laboratory investigations have resulted in a revised understanding of the relevant microbial processes.

Reliability and replacement characteristics of Great Lakes marine diesel engines have been studied. A Colt-Pielstick PC2-400 series marine diesel engine has been used as a prototype for our modeling. Failure Modes and Effects, and Fault Tree analyses for our engine have been performed. Censored field data have been processed from six identical engines of the above type. Parameters of Weibull and Exponential PDF's have been evaluated for seven vital system components, namely connecting rod bearing, cylinder head, cylinder jacket, cylinder liner and o-ring, cylinder piston, and fuel cam. Reliability and hazard functions for these items have been derived and discussed using both above PDF's. Exponential PDF's have been found to be inappropriate for representations of components failure times. Reliability based models have been developed and implemented to rationalize current winter layup replacement practices. Two systems have been considered: One for a ship equipped with one engine only and another for a two-engine ship. Incorporating the age dependent nature of system failure characteristics, a semi-Markov competing-process approach has been used in our models, where system failure behavior has been treated as a race among engine components. Howard's one-set competing process model has been implemented and extended to two sets of competing processes. A recursive iteration procedure has been used in the expected cost calculation. An efficient enumeration procedure has been presented to select the replacement policy which produces the minimum expected cost for an operating season. Computer codes have been developed using the above models, and several examples have been examined. Sensitivity analyses have been performed for several parameters for which we had insufficient or no information from the industry to see the influence of their variation on our expected costs and corresponding winter layup policies. We have observed that current replacement practices are conservative. Our results have also indicated that the total expected cost function changes almost linearly with time for our parameters. However, this linearity is very sensitive to the length of operating season. As far as replacement policies are concerned, there is a group of good replacement policies immediately following the best replacement policy; differences between the total expected costs resulting from these policies are not very significant for some cases within our parameter range. Besides, the value of the minimum expected cost function is very sensitive to component ages, and operating costs.

Thallium in the environment is of concern because of its high toxicity and growing use by modern high tech industries. This thesis presents a systematic study of the sources, behavior and fate of thallium in the Great Lakes ecosystem. An ion-exchange separation technique followed by analysis with atomic absorption spectroscopy was used to study the chemical speciation and distribution of thallium in Lakes Michigan, Huron and Erie as well as Huron River and Raisin River. The detection limit for the method employed was 1 ng/L for both Tl(I) and Tl(III). Analysis of synthetic solutions consistently yielded $>$90% recovery of these two thallium forms with negligible cross contamination. The dominant thallium form found in Great Lakes waters was the oxidized Tl(III) which comprised 68 $\pm$ 6% of the total dissolved thallium. The proportion of Tl(III) to the total dissolved thallium in the Raisin and Huron Rivers ranged from 43 to 73% and averaged of 66% in these waters. A preliminary study suggests that a significant proportion of Tl(III) may be in colloidal form. No definite spatial (horizontal or vertical) pattern was found in the distribution of total dissolved thallium in the water column of Lakes Michigan, Huron and Erie. An overall decline of thallium concentration from Lake Michigan to Lake Erie was observed which may be related to rapid scavenging removal from the water column. The preliminary budget estimate suggests that atmospheric (64%) and riverine (20%) inputs are the major sources of thallium into Lake Michigan with the flux to sediments representing 80% of the total loading. Thallium is highly accumulated in lake trout, the estimated bioaccumulation factor being about 10,000. Simple calculation of thallium exposure due to consumption of the lake trout suggests that some anglers may be at risk of getting chronic thallium poisoning. The effects of thallium pollution of the Great Lakes on the health of people (and wildlife) have not been recognized previously.