The 2006 Clean Water Act requires each municipality to come up with science-based plans to protect the quality and quantity of their drinking water. A literature review concerning applicable processes in Lake Ontario along with previous modelling of the lake is presented. The three dimensional Estuary, Lake and Coastal Oceans Model (ELCOM) is used to model Lake Ontario on a 2×2km grid scale. The model is forced using meteorological data from the 2006 summer season, inflows and outflows. The lake-wide model is evaluated using field data from thermistor chains and ADCPs as well as historical water level data. Simulated and observed temperature profiles compared well. However, modelled temperature profiles were slightly cooler than observed. Current results were more variable than temperature profile results but compared better to observed data in the offshore regions. Simulating Lake Ontario water levels proved to be problematic because an accurate water balance is difficult to force with a large drainage basin. A 300×300m nearshore model of the eastern portion of Lake Ontario and the upper St. Lawrence River is also presented. The open boundary is forced using temperature data which is (A) varied with depth, (B) constant with depth and (C) spatially varied over the length of the open boundary and varied with depth. Both spatially varied and non-varied water level data forcing the open boundary is also compared. Spatially varied temperature and water level data is computed from the coarse grid lake-wide model. Lake-wide coarse grid model error appears to propagate through the open boundary negatively affecting nearshore modelled current when coupling the models. It was concluded that lake-wide model results should not be used to force the open boundary for the nearshore model. Nearshore model results using constant temperature with depth forcing files and non-spatially varied water level data agree well with observed temperature profiles, but further analysis is required for better confidence in the model's ability to properly reproduce currents at a 300×300m grid scale. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-10-07 10:08:44.145

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The lake sturgeon, Acipenser fulvescens, was once abundant throughout Canada and the United States, however, high commercial harvests and habitat alterations have dramatically reduced most populations. The species was extirpated from many rivers that it once inhabited, and has been designated as threatened or endangered throughout its range. Currently, few healthy lake sturgeon populations remain and the species is receiving considerable attention with respect to its protection and recovery. Although considerable effort is underway to conserve the species, several factors, including over-harvest and habitat alteration, pollution and a general lack of understanding about lake sturgeon ecology and behavior continue to hamper recovery efforts. This thesis examined the ecology and behavior of juvenile lake sturgeon within a 41 km long impounded section of the Winnipeg River, a large river in the Canadian Shield, over a three-year period (2006 – 2008). Habitat preferences, species associations, diet, and movement were described on a seasonal basis. Biological characteristics were also described for juvenile lake sturgeon within the study area. Studies presented in this thesis are among the first conducted for juveniles of this species in the Hudson Bay drainage basin, and from large riverine environments in general. Results are important, not only for improving our understanding of lake sturgeon at the juvenile life history stage, but for facilitating further research. In particular, future research studies identified in the final chapter have the potential to enhance our understanding of factors influencing mortality during the early life history stages of the lake sturgeon, and therefore, greatly enhance recovery efforts.

Climate change effects have been documented in the Canadian Prairie Provinces. Temperature is predicted to continue to increase, and precipitation patterns are changing. As a result, river flow is anticipated to diminish. The South Saskatchewan River (SSR) provides vital habitat to lake sturgeon. Lake sturgeon are currently endangered or threatened across most of their native range, prompting provincial governments to develop management strategies. As lake sturgeon habitat is dependent on flow, understanding climate change impacts on flow conditions in the SSR will be an important component of their long-term management strategy for lake sturgeon. I have developed empirical models based on regional climate variables (temperature and precipitation) to predict in-stream flow. These models were developed using general linear modeling and Akaikes Information Criterion (AIC). Future in-stream flow was predicted by extracting key variables from 5 different GCM’s and inserting the variables into the predictive flow models. These future flow scenarios were coupled with habitat suitability indices developed to assess changes in sturgeon habitat developed by the Water Security Agency and Department of Fisheries and Oceans Canada. Flow scenarios predict a decrease in the habitat of most life stages (spawning, juvenile, adult and subadult), but an increase in fry habitat. These models will represent a novel advancement for sturgeon management in Western Canada.

The Summer (May through August) community of crustacean zooplankton and zebra mussel (Dreissena polvmorpha) larvae at a 15 m sample site in Lake Michigan near Michigan City was evaluated for the years 1990 through 1994. Yearly mean densities were compared with investigations done at the same sample location by Johnson (1972) and Ball State University (unpublished data) during 1970 and 1971, respectively to investigate possible changes in community composition during the past 25 years. Potential declines in crustacean zooplankton relating to the 1991 introduction of the filter-feeding zebra mussel were also evaluated.Overall declines in major species since 1970-71 included Bosmina longirostris, Daphnia retrocurva, and Diacyclops thomasi. Recent increases in the nearshore fish population of alewife (Alosa pseudoharengus) and spottail shiner (Notropis hudsonius) may have influenced the densities of these species in recent years. Copepod nauplii were the only crustaceans to increase in overall abundance since the period of 1970-71, as the number of invertebrate predators appeared to decrease. Other species did not show any noticeable change in long-term abundance or during the 1990-94 period.Zebra mussel larvae were first observed in the zooplankton complex studied on June 17, 1991. -Densities of larvae reached maximal levels for the period of study in 1994 with two large reproductive pulses of 195,000 and 210,000/m3 in June and August, respectively. The mean abundance during 1994 made up 65% of the total crustacean zooplankton/zebra mussel community complex. Evaluation of the vertical stratification of zebra mussel larvae in 1994 revealed a strong (r2=0.75, p<0.0005) tendency for veligers to remain in the upper 10 m of the water column due to thermal stratification. / Department of Biology

Selectivity of trawl and experimental gill nets was determined for yellow perch taken from southern Lake Michigan in 1993 to 2006. Gill nets were comprised of 51-, 64-and 76-mm size mesh and showed female modal lengths of 205-, 245-, and 295-mm, respectively, while values for males were 200-, 230-, and 267-mm. Differences between females and males increased with mesh size and was significant. Comparison of nine anterior morphometric features of female and male fish indicated no differences in shape were identified that would cause the disparity in selectivity. Rather, differences in male and female selectivity were more likely due the variant population size structure of the local population sampled, with females the larger sex. A new method to estimate trawl selectivity was developed using a modified catch-curve analysis, which showed a maximum selectivity length value (1.0) of 190-mm for females and 170-mm for males. However, trawls fail to capture larger yellow perch when compared to gill nets using based on length-frequency distributions. Revealing such gear biases may lead to more efficient capture methods, resulting in improved sampling and quantitative assessment of fish populations. / Department of Biology

I determined differences in yellow perch gill-net catch-per-unit-effort (CPUE) at two depths (10 and 15 m) in the Indiana waters of Lake Michigan during June, July, and August from 1989 to 2006. I evaluated the abiotic factors of water temperature, water clarity, wave height, and wind direction to determine whether they influence the differences in yellow perch CPUE. This study suggests that yellow perch in southern Lake Michigan may select habitat based on water temperature during the summer, moving in response to thermocline changes. We also evaluated mortality rates for two distinct periods (1984-1994 and 2000-2007) in order to identify the response of the population to changes in exploitation. Yellow perch during 1984-1994 (high exploitation) and 2000-2007 (low exploitation) displayed an increase in mortality for fish of harvestable size. In addition, during 2000-2007 (low exploitation) we identified that female yellow perch reached exploitable size earlier in life than males. / Department of Biology

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Biology

Pharmaceuticals and personal care products (PPCPs) enter aquatic ecosystems through multiple pathways including human excretion into sewage systems, disposal of surplus drugs, and the therapeutic treatment of livestock. Because PPCPs are designed to have a physiological effect, it is likely that they may also influence aquatic organisms. The objectives of this research were to quantify PPCP abundance in near-shore habitats of Lake Michigan and identify factors related to PPCP abundance. Stratified sampling was conducted seasonally at four southern Lake Michigan sites. All sites sampled had measurable PPCP concentrations, but they varied significantly among time and location. Concentrations of PPCPs did not differ with site or water depth. Multiple regression analyses revealed that temperature, total carbon, total dissolved solids, dissolved oxygen, and ammonium controlled total PPCP concentrations. These data indicate PPCPs are ubiquitous in southern Lake Michigan with continued research needed to assess potential effects on aquatic organisms and humans. / Department of Biology