Carol Collins

Light intensity and temperature interactions have a complex effect on the physiological process rates of the filamentous bluegreen alga Anabaena variabilis Kütz. The optimum temperature for photosynthesis increased with increasing light intensity from 10°C at 42 μE·m−2·s−1 to 35°C at 562 μE·m−2·s−1. The light saturation parameter, IK, increased wit...

Discusses phytoplankton and macrophytes leading to modification of the taste, odour, algal scums, oxygen depletion at depth, and aquatic weed beds. -D.J.Davis

A macrophyte submodel has been incorporated and tested in CE-QUAL-R1, a one-dimensional, vertically averaged model of reservoir water quality. A quasi two-dimensional scheme was necessary to represent the spatial relationship of macrophytes in reservoirs adequately. The macrophyte processes modeled were photosynthesis, dark respiration, excretion a...

Lake George, New York, is generally considered an oligotrophic phosphorus-limited lake. Yet, the supply and recycling rates of nitrogen and silica may also be critical in regulating phytoplankton productivity, species composition, and abundance. Biweekly phytoplankton bioassays were conducted in 1986 and 1987 at three stations in Lake George to mea...

The distributional patterns of 38 species of submersed macrophytes were studied at 50 sites in the littoral periphery of Lake George, New York. Density measurements (plants per square meter) for each species at depths of 1, 2, 3, 5, 7 and 9 m were determined at transects at each site and converted to midsummer shoot biomass estimates (grams dry mas...

Numerical techniques used in biological oceanography and limnology must take into account ecological hypotheses to be tested and the specific nature of aquatic data. These techniques can be used either for examining data sets (exploratory data analysis) or for estimating population or subpopulation characteristics from samples (inferential statisti...

CE-QUAL-R1 is a one-dimensional model being developed by the Corps of Engineers to predict and assess the effects of engineering activities on reservoir water quality. Evaluation consisted of tests of the code and comparisons of model predictions with field measured values. Tests of the code included evaluations of the stability of predictions, con...

A one-dimensional model (CE-QUAL-R1) of water quality of reservoirs was evaluated using data collected on the Eau Galle Reservoir, in west-central Wisconsin. Data collected on the Eau Galle Reservoir, in west-central Wisconsin. Data collected in 1982 were used for confirmation. Graphical and statistical comparison were made for over 6.500 samples r...

The U.S. Army Corps of Engineers' 1-dimensional model (CE-QUAL-R1) was evaluated using data collected at a small (46 ha, mean depth of 3.7 m) eutrophic reservoir near Spring Valley, WI, U.S.A. The model predicts the gradients, in the vertical direction, of water quality variables including temperature, chemical species, and biological assemblages....

Emphasis on evaluation techniques where measured versus predicted changes of mass are compared can produce a model that predicts the correct answers for the wrong reasons. The movement of mass between compartments (flux) should be compared to measured flux as part of the model verification. Model verification techniques need to reflect the same lev...

Cultures of Anabaena variabilis were exposed to different light intensities, and the time course of photoadaptation was measured by photosynthetic rate and changes in pigmentation. A shift down in intensity of 284 muEin . m . sec caused a temporary decrease in the photosynthetic response followed by gradual adaptation to the new conditions. Final c...

A submodel for internal nutrients, critical to prediction of phytoplankton growth dynamics, is described. Process equations were developed to represent storage of nutrients with separate mechanisms for nutrient uptake and assimilation, multiple-nutrient limitation by the threshold hypothesis, and light-dependent photorespiration. These have been in...