Defining algal bloom phenology in Lake Erie

Area of Science:

• Environmental Science
• Ecology
• Limnology

Background:

• Climate change is altering aquatic ecosystems globally.
• Phenological shifts in primary producers are key indicators of ecological resilience.
• Harmful algal blooms (HABs) pose significant threats to water quality and ecosystem health.

Purpose of the Study:

• To investigate phenological shifts in chlorophyll and microcystin concentrations in Lake Erie.
• To identify critical phenological phases for estimating HAB duration, magnitude, and intensity.
• To develop a repeatable methodology for HAB analysis to aid in water quality management.

Main Methods:

• Utilized Bayesian generalized additive mixed models to analyze seasonal chlorophyll and microcystin data.
• Employed a simple geometric method to identify the start, peak, and end of algal blooms.
• Tracked temporal changes in chlorophyll (as a proxy for algae biomass) and microcystin concentrations.

Main Results:

• Successfully described seasonal patterns of chlorophyll and microcystin in Lake Erie.
• Developed a novel method to identify key phenological phases of algal blooms without user-defined cutoffs.
• Provided a framework for understanding the ecological effects of nutrient pollution on aquatic ecosystems.

Conclusions:

• The developed methodology enhances understanding of HABs and their drivers.
• This research offers a repeatable approach for HAB phenology assessment, crucial for water resource management.
• The findings support efforts to mitigate HABs and safeguard drinking water quality in Lake Erie and similar regions.