Nutrient drivers of cyanobacterial blooms in lower New York State lakes

Session: Poster Session

Michael Kausch, Fordham University, [email protected]
John Wehr, Fordham University, [email protected]

Abstract

In recent decades, cyanobacteria blooms have increased in occurrence and intensity, and are now a global water quality issue. In New York State, cyanobacteria blooms have led to greater concentrations of toxins in sources of drinking water, beach closures, and illness associated with exposure. One of our key aims is to identify ecosystem drivers of blooms of non-diazotrophic cyanobacteria. We analyzed 59 samples in summer 2018 from lakes in lower New York State for aqueous nutrients, particulate N:P ratios, and algal pigments (chla, phycocyanin). Sampling locations varied with respect to land use and human population density. Chla concentrations ranged from 0.4 to 179.2 µg/L, and Secchi depths from 0.15 to 5.7 m, with 20 samples (> 30%) indicative of eutrophic or hypereutrophic conditions. Analysis of aqueous nutrient concentrations (forms and concentrations of dissolved N and P) and particulate N:P ratios will be employed to estimate cellular nutrient status of phytoplankton assemblages. Here we focus in particular on the role of nitrogen in cyanobacterial bloom formation in high-P systems. We will then use these data to design mesocosm experiments to more accurately identify the role of different forms of N in blooms of non-diazotrophic cyanobacteria.

Twitter handle of presenter
@NYCmicrobes