Early and late cyanobacterial bloomers in a shallow, eutrophic lake

Abstract

Cyanobacterial blooms present challenges for water treatment, especially in regions like the Canadian prairies where poor water quality intensifies water treatment issues. Buoyant cyanobacteria that resist sedimentation present a challenge as water treatment operators attempt to balance pre-treatment and toxic disinfection by-products. Here, we used microscopy to identify and describe the evolution of cyanobacterial species in Buffalo Pound Lake, a key drinking water supply. We used indicator species analysis to identify temporal grouping structures throughout two sampling seasons from May to October 2018 and 2019. Our findings highlight two key cyanobacterial bloom phases – a mid-summer diazotrophic bloom of Dolichospermum spp. and an autumn Planktothrix agardhii bloom. Dolichospermum crassa and Woronchinia compacta served as indicators of the mid-summer and autumn bloom phases, respectively. Different cyanobacterial metabolites were associated with the distinct bloom phases in both years: toxic microcystins were associated with the mid-summer Dolichospermum bloom and some newly monitored cyanopeptides (anabaenopeptin A and B) with the autumn Planktothrix bloom. Despite forming a significant proportion of the autumn phytoplankton biomass (> 60%), the Planktothrix bloom had previously not been detected by sensor or laboratory-derived chlorophyll-a. Our results demonstrate the power of targeted taxonomic identification of key species as a tool for managers of bloom-prone systems. Moreover, we describe an autumn Planktothrix agardhii bloom that has the potential to disrupt water treatment due to its evasion of detection. Our findings highlight the importance of identifying this autumn bloom given the expectation that warmer temperatures and a longer ice-free season will become the norm.

Co-Authors

• Kristin Painter, University of Saskatchewan, kristin.painter@usask.ca, ORCID 0000-0003-3264-0961
• Jason Venkiteswaran, Wilfrid Laurier University, jvenkiteswaran@wlu.ca, ORCID 0000-0002-6574-7071
• Dana Simon, Université de Montréal, df.simon@umontreal.ca,
• Sung Vo Duy, Université de Montréal, sung.voduy@yahoo.fr
• Sébastien Sauvé, Université de Montréal, sebastien.sauve@umontreal.ca
• Helen Baulch, University of Saskatchewan, helen.baulch@usask.ca, ORCID 0000-0001-9018-4998

Corresponding Author

• Kristin Painter, University of Saskatchewan, kristin.painter@usask.ca, ORCID 0000-0003-3264-0961

Funding sources

• Global Water Futures: FORecasting tools and Mitigation options for diverse BLOOM-affected lakes (FORMBLOOM)
• Genome Canada and Genome Quebec: Algal Blooms, Treatment, Risk Assessment, Prediction and Prevention through Genomics (ATRAPP)
• Mitacs Accelerate Industry Partnership with the Buffalo Pound Water Treatment Plant

Keywords

harmful algal bloom, cyanobacteria, water treatment

Geographic Coverage

• Site coordinates: 50°35’8.8” N, 105°23’0.24” W

Temporal Coverage

• Start: 2018-05-29
• End: 2019-10-03

Additional information and support

• Sensitive Data Flag - Human Participants: NO
• Sensitive Data Flag - Indigenous Partnerships: NO
• Sensitive Data Flag - Government Partnerships: NO
• Sensitive Data Flag - Industry Partnerships: YES
• Access Restrictions

Software

R version 4.0.5

Repo content information

data/raw_data

Raw data files in various formats. Original files generated by analytical equipment, received from a data provider or outside contractor, etc.

data/clean_data

Clean data in formats for long-term storage. Modified data with the appropriate column/row headers and data structure.

data/processed_data

Processed data used in analysis and to create figures.

code

Scripts for processing data and creating figures, outside derived code, and user derived code.

docs

Project notes, other documentation, etc.

output

Figures and tables produced from analysis.