Duelling ‘CyanoHABs’: unravelling the environmental drivers controlling dominance and succession among diazotrophic and non‐N 2 ‐fixing harmful cyanobacteria
Year: 2015
Type: review
Abstract: Eutrophication often manifests itself by increased frequencies and magnitudes of cyanobacterial harmful algal blooms (CyanoHABs) in freshwater systems. It is generally assumed that nitrogen-fixing cyanobacteria will dominate when nitrogen (N) is limiting and non-N2 fixers dominate when N is present in excess. However, this is rarely observed in temperate lakes, where N2 fixers often bloom when N is replete, and non-fixers (e.g. Microcystis) dominate when N concentrations are lowest. This review integrates observations from previous studies with insights into the environmental factors that select for CyanoHAB groups. This information may be used to predict how nutrient reduction strategies targeting N, phosphorus (P) or both N and P may alter cyanobacterial community composition. One underexplored concern is that as N inputs are reduced, CyanoHABs may switch from non-N2 fixing to diazotrophic taxa, with no net improvement in water quality. However, monitoring and experimental observations indicate that in eutrophic systems, minimizing both N and P loading will lead to the most significant reductions in total phytoplankton biomass without this shift occurring, because successional patterns appear to be strongly driven by physical factors, including temperature, irradiance and hydrology. Notably, water temperature is a primary driver of cyanobacterial community succession, with warming favouring non-diazotrophic taxa.
Source: Environmental Microbiology
Authors: Hans W. Paerl, Timothy G. Otten
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
Awards: INSPIRE: An Ecologically-Driven Strategy for Ensuring Sustainability of Anthropogenically and Climatically Impacted Lakes, G3310084242, Is Nitrogen Nitrogen? Ecosystem Impacts of Anthropogenic N Sources on Algal Blooms, Hypoxia, and Biogeochemical Cycling in the Neuse River Estuary, NC, Collaborative Research: Evaluating Nutrient Reductions to Control Cyanobacteria and Ensure Large Lake Sustainability: Lake Taihu (China) as a Model for North American Systems, The Role of Sediment-Water Column Biogeochemical Feedback in Eutrophication Dynamics of the Neuse River Estuary, NC
OpenAlex ID: W1818480214