Abstract

The open pelagic water of Lake Ontario have experienced a major decrease in chlorophyll and phosphorus and an increase in transparency over the past 30 years. These improvements in water quality have not been observed in the nearshore waters along the southern coast of Lake Ontario. For three years, 22 U.S. sites were monitored monthly from the Niagara River to Chaumont Bay. Samplings sites included bays, rivers, ponds and the coastal zone of Lake Ontario. Parameters included total phosphorus, soluble reactive phosphorus, total Kjeldahl nitrogen, nitrate, chlorophyll, phycocyanin, total suspended solids and microcystins. Results indicate that ambient phosphorus levels in the coastal nearshore region exceed N.Y.S. DEC Guidelines and that abundance of nuisance algae are significantly higher than offshore regions of Lake Ontario. For example, total phosphorus concentration reached as high as 323 ug P/L in the nearshore. Similarly, chlorophyll concentrations reached as high a 396 at the same location.