| Summary |
Equations relating river time-of-travel, light penetration into the water column, and river depth to river flow were developed from data collected on the Neuse River. Laboratory data on the growth rate of M. aeruginosa under a range of temperature and light conditions were used to develop equations relating growth rate to light intensity, photoperiod, and temperature. These equations were incorporated into a mathematical model. The model was used to predict M. aeruginosa blooms in the Neuse under a given set of flow, light, and temperature conditions. The model was validated by comparing model predictions of bloom occurrence from 1978 to 1986 to field observations of bloom occurrence over this time period. Once validated, the model was used to determine river flow and temperature conditions that allow bloom formation in the Neuse. The month of July is most susceptible to bloom formation, according to model output. Also, blooms can be prevented from developing if river flow at Kinston is above 550 cfs. Based on sensitivity analysis, water temperature and daylength have the greatest effect in determining flow rates that prevent bloom development. Based on the model, river flow conditions at or below critical levels for bloom formation occurred 25 times from 1940 to 1986. Also, periods of high winter-spring nutrient loading are not necessary, at the present time, to support bloom formation in the lower Neuse. |
