Influence of pH and total dissolve solids on harmful algal blooms of Prymnesium parvum.

Harmful blooms of Prymnesium parvum in inland waters continue to expand, in part, due to anthropogenic influences and climate change. This thesis examines influences of pH and total dissolved solids (TDS) on P. parvum blooms, growth, and toxicity to aquatic life. Chapter 1 evaluated pH effects on P. parvum bloom development and toxicity by manipulating in situ limnocorrals during 21 d pre-bloom and bloom development experiments. Though neutral pH levels preempted P. parvum bloom development, higher pH resulted in bloom formation and ambient toxicity. Chapter 2 examined whether TDS with major ionic composition associated with hydraulic fracturing influenced P. parvum growth and toxicity across nutrient conditions. Though no growth was observed at 130 mg/L, higher treatment levels of TDS stimulated P. parvum growth and increased acute toxicity to fish. Such novel observations provide pH and TDS thresholds for potentially supporting management of P. parvum growth and acute toxicity in inland waters.