Laboratory Studies To Assess Toxic Microcystis Growth And Toxicity Under Varying Temperatures In Lake Pontchartrain, Louisiana (Urop Report)

Estuaries in the northern Gulf of Mexico are undergoing profound alterations due to changes in climate and implementation of coastal restoration activities and these may lead to increasing frequency of harmful cyanobacteria blooms (CyanoHABs). The introduction of large volumes of nutrient-rich, fresh Mississippi River water into nutrient-poor estuarine Lake Pontchartrain is known to substantially change the chemistry and ecology of the lake, and warm temperatures paired with the persistent nutrient loading into the lake supports the proliferation of CyanoHABs. Different environmental factors can control cyanobacteria community structure and their toxin production. With climate change drivers increasing the temperature regime of these freshwater ecosystems and selecting for more cyanobacteria, these CyanoHABs are posing a serious threat to the use and sustainability of existing freshwater resources. Therefore, management strategies targeting the specific environmental conditions that lead to cyanobacteria bloom development and the associated toxin production are critically needed. In this proposed project, we used existing field data to characterize estuarine spring conditions and conduct series of laboratory experiments to understand the effect of temperature variability on locally isolated Microcystis growth and toxin production.