Seventy-one aquatic species including the copepodids and nauplii were identified from Lake Texoma from August 1996 to September 1997. Zooplankton community structure, abundance and spatial and temporal distributions were compared among five lake zones delineated a priori based on chloride concentration. The zones, in order of decreasing chloride concentration, are the Red River zone (RRZ), Red river Transition zone (RRTZ), Main Lake zone (MLZ), Washita River Transition zone (WRTZ) and Washita River zone (WRZ). Bray Curtis Similarity Index showed community structure was most similar in the two Red River arm zones, the two Washita River arm zones and the MLZ. Zooplankton abundance was greatest in the Red River arm (312 org/L), intermediate in the Washita River arm (217 org/L) and least in the Main Lake body (103 org/L). A significant increase in the abundance of a deformed rotifer, Keratella cochlearis, was observed mainly in the Red River arm during a second study from March 1999 to June 1999. Seasonal dynamics, rather than spatial dynamics, were more important in structuring the zooplankton community, especially in the two river arms. Spatial variance was solely attributed to station and zone effects independent of time for a few crustacean species and many of the water quality parameters supporting the presence of longitudinal gradients of differing water quality. Three independent models (Red River arm, Washita River arm, Main Lake body) rather than a single model for the entire reservoir, best describe patterns in the zooplankton community and its relationship to seasonal, physical and chemical factors. Statistical power, sample size and taxonomic resolution were examined. When monitoring seasonal and annuals trends in abundance, the greatest statistical power was achieved by analyzing count data at taxonomic levels above genus. Taxonomic sufficiency was assessed to determine if costs could be reduced for zooplankton identifications. For water quality monitoring purposes only, it is recommended that genus identifications are sufficient if supplemented with quarterly species identifications.

Anthropogenic hydrologic alterations can affect the quality of lake littoral zone habitats for wading birds, such as the great egret (Ardea alba), snowy egret (Egretta thula), and white ibis (Eudocimus albus). One such lake in Florida, Lake Okeechobee, has experienced a marked decline in wading bird nesting since the 1970’s, concomitant with changes in lake level management. It’s hypothesized that a reduction in foraging habitat has led to the nesting decline; however, there is little quantitative evidence of this link. A habitat suitability model was developed for Lake Okeechobee wading birds that incorporate the spatial and temporal dynamics of environmental factors that affect wading bird foraging and tests whether foraging habitat is linked to numbers of nests. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

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To slow climate change, humans should take immediate and widespread action. One way to slow climate change is by switching to switch to renewable power plants such as solar fields. Recently, pioneering companies have built solar fields on water bodies. This study found that such a pairing of water and solar could increase production efficiency by 8-10% through panel cooling, save millions of liters of water from evaporation, and produce energy with under-utilized space.

Time series of brightness temperature (TB) measurement obtained at various frequencies by the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) are investigated to determine ice phenology parameters and ice thickness on Great Bear Lake (GBL) and Great Slave Lake (GSL), Northwest Territories, Canada. TB measurements from the 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization) are compared to assess their potential for detecting freeze-onset (FO)/melt-onset (MO), ice-on/ice-off dates, and ice thickness on both lakes. The sensitivity of TB measurements at 6.9, 10.7, and 18.7 GHz to ice thickness is also examined using a previously validated thermodynamic lake ice model and the most recent version of the Helsinki University of Technology (HUT) model, which accounts for the presence of a lake-ice layer under snow. This study shows that 18.7 GHz H-pol is the most suitable AMSR-E channel for detecting ice phenology events, while 18.7 GHz V-pol is preferred for estimating lake ice thickness on the two large northern lakes. These two channels therefore form the basis of new ice cover retrieval algorithms. The algorithms were applied to map monthly ice thickness products and all ice phenology parameters on GBL and GSL over seven ice seasons (2002-2009). Through application of the algorithms much was learned about the spatio-temporal dynamics of ice formation, decay and growth rate/thickness on the two lakes. Key results reveal that: 1) both FO and ice-on dates occur on average 10 days earlier on GBL than on GSL; 2) the freeze-up process or freeze duration (FO to ice-on) takes a comparable amount of time on both lakes (two to three weeks); 3) MO and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL; 4) the break-up process or melt duration (MO to ice-off) lasts for an equivalent period of time on both lakes (six to eight weeks); 5) ice cover duration is about three to four weeks longer on GBL compared to its more southern counterpart (GSL); and 6) end-of-winter ice thickness (April) on GBL tends to be on average 5-15 cm thicker than on GSL, but with both spatial variations across lakes and differences between years.

This study aims at elaborating the Integrated Lake Basin Management Planning (ILBM) approach, which is considered as a sustainable management model for lake basins, and evaluating the applicability of this approach in Turkey. ILBM considers both biophysical features and managerial requirements of lake basin systems. It pays attention to inherent dynamics between humans and nature. ILBM has been developed on the basis of Integrated Water Resources Management (IWRM), which seeks the wise use of water / i.e. using water resources with reference to the conservation principles and thresholds. The study elaborates the ILBM planning and focuses on a case study, namely the Beysehir Lake Basin. Beysehir Lake is the third largest lake and biggest freshwater lake of Turkey. Its basin is important with the distinctive natural features it accommodates in two national parks, a special bird site, a special plant site and a natural protected site. However, improper use of the Lake&rsquo / s resources has threatened its natural and ecological qualities, despite the simultaneous conservation efforts. This study, having analyzed the past planning efforts on the Basin with regard to the ILBM principles and criteria, points to the insufficiencies in institutional structure and participation. Meanwhile, the study --depending on the findings of a questionnaire conducted with the stakeholders of the Basin-- also underlines that most of the stakeholders are unaware of the changes that the Lake faced, and they do not know about the existing plans of the Basin. This proves the need for stronger interinstitutional relationships and cooperation so as to take coherent actions. This is important for the management and planning in lake basins, but particularly in the ones which lie on more than one settlement&rsquo / s administrative boundaries like the Beysehir Lake. For the efficient and effective implementation of the ILBM in Turkey&rsquo / s lake basins, the related legislation should be revised accordingly.

Environmental regulation of nitrogen cycling processes, denitrification and nitrification, was studied in sediment of Hamilton Harbour, with particular emphasis on the role of CH$ sb4$ metabolism (production and consumption). Through extensive sediment sampling and numerical analysis, it was found that particulate carbon was the best predictor of potential for anaerobic production of CH$ sb4$ and CO$ sb2$. The only predictor of denitrification capacity was anaerobic CO$ sb2$ production, indicating that beside NO$ sb3 sp-$ and O$ sb2$, a biotic factor involved in carbon metabolism may be important in the control of this activity. / Suppression of aerobic N$ sb2$O production in sediment slurries by C$ rm sb2H sb2$ and correlation with NO$ sb3$-production indicated that it was dependent on chemolithotrophic nitrification. Although CH$ sb4$ (1 to 24 $ mu$M) stimulated production of NO$ sb3 sp-$ and N$ sb2$O, we found that CH$ sb4$ at 84 $ mu$M or greater suppressed nitrification. Following extensive studies of pore water chemistry, potential microbial activities, and counts of nitrifiers and methanotrophs, we found that CH$ sb4$ oxidation (i) is more likely to suppress nitrification by competition for O$ sb2$ and NH$ sb4 sp+$ between methanotrophs and nitrifiers, and (ii) may be more important than nitrification as a sink of hypolimnetic O$ sb2$ in Hamilton Harbour. / Amongst a number of inhibitors, allylsulfide was found to be a differential inhibitor with much less effect on CH$ sb4$ oxidation in sediment slurries or in axenic cultures of Methylosinus trichosporium OB3b than on nitrification in sediment slurries.

The population dynamics of alewives Alosa pseudoharengus and spottail shiners Notropis hudsonius were investigated in Indiana waters of Lake Michigan from 1984-1996. Insights to population dynamics of both species were found by applying age and growth information to length-frequency distributions of index trawl catches within and between years. Both alewife and spottail shiner populations showed general increasing trends over the period, reaching peak levels in 1996. Interaction potential was examined for alewives, spottail shiners, and the yellow perch Perca flavescens, another important nearshore species. Trends in relative catches of these species were correlated to provide insight to possible interactions. There appears to be negative relationships between alewife and yellow perch populations, as well as between yellow perch and spottail shiner populations. No relationships were found between alewife and spottail shiner populations. / Department of Biology

Yellow perch, alewife, spottail shiner and round goby trawl catch per unit effort (CPUE) was evaluated in the Indiana waters of Lake Michigan from 1984-2006 to determine whether spatial or temporal variation in CPUE for these species occurred. Differences in CPUE among sites or periods were not clearly distinguished within a single sampling year. However, when compared over a 23 year time frame, spatial and temporal differences became evident. To determine the minimum number of samples needed to detect differences among sites and periods, we ran a Monte Carlo simulation using 23 years of empirical data. This compared favorably to results obtained from a power analysis that identified the minimum number of samples required to identify statistical differences. Sampling effort needed to distinguish differences in CPUE varied both spatially and temporally among the four species. Differences in sampling only became evident when multi-year efforts were employed. In addition, spatial and temporal differences in male and female (mature and immature) yellow perch proportions was also evaluated among our sample sites and periods from 1993-2006. / Department of Biology

No description available.