The Effects of Nitrogen Dynamics on Toxic, Non-Diazotrophic Microcystis spp. in Eutrophic Lakes

Session: 38. - Nutrient Sources, Transport and Retention in Great Lakes Watersheds: Field Measurements, Modeling and Management Implications

Omar Al-Dabbagh, McMaster University, [email protected]
Gail Krantzberg, Engineering and Public Policy, Program, McMaster University, [email protected]
Velma Grover, McMaster University, [email protected]

Abstract

Nitrogen (N) and phosphorus (P) compounds are pollutants associated with eutrophication and the increasing occurrences of cyanobacterial harmful algal blooms (CyanoHABs) in freshwater ecosystems. The environmental concern of CyanoHABs is that certain taxa are able to produce high biomass, biotoxins, noxious odor and taste compounds, and hypoxic zones in impacted water bodies, affecting the human and animal health, ecosystem services, and the economy.

Although P has been understood as the primary driver of the biological productivity of freshwater systems, the precise role of N dynamics linked to the blooms of toxic Microcystis species needs more clarifications. Based on this, the first objective of this study is to investigate N transformations and fluxes in eutrophic lakes. The second goal is to illustrate the impacts of different N forms on the growth and toxicity of non-N₂ fixing Microcystis spp. and inform policy around their control.

1. Keyword
harmful algal blooms

2. Keyword
Microcystis

3. Keyword
biogeochemistry

4. Additional Keyword
Nitrogen forms

5. Additional Keyword
Eutrophication

6. Additional Keyword
Nutrient reduction policies