Factors Regulating Nuisance Blue-Green Algal Bloom Potentials in the Lower Neuse River, North Carolina

摘要

Bi-weekly examinations of physical, chemical, and biotic factors involved in the establishment and proliferation of blue-green algal (Microcystis aeruginosa) blooms in the lower Neuse River indicated several causative agents. Included are: excessive concentrations of both nitrogen and phosphorus throughout much the year and periods of low flow and decreased turbulence (vertical mixing), leading to thermal stratification of the water column. Periods of thermal stratification, even lasting only a day or two, are instrumental in promoting dominance by surface-dwelling Microcystis populations. A combination of these physical and chemical agents leads to maximal bloom development. Preliminary experiments indicate that nitrogen, largely as NO3(3), reductions (of at least 30%) are more effective than phosphorus reductions in arresting bloom potential.