@article{10272/24854,
year = {2024},
month = {11},
url = {https://hdl.handle.net/10272/24854},
abstract = {Lake cyanobacteria can overgrow and form blooms, often releasing life-threatening toxins.
Harmful algal blooms (HABs) are typically caused by excess nutrients and high temperatures, but
recent observations of cyanobacteria beneath the ice in boreal lakes suggest that the dynamics are
more complex. This study investigates the seasonal dynamics of HABs in boreal lakes and identifies
their driving factors. We study cyanobacteria assemblages in two boreal lakes in Abitibi-
T´emiscamingue (Quebec, Canada): Lake Fortune, noted for its under-ice cyanobacteria, and Lake
Beauchamp, which has experienced recurrent summer-only cyanobacterial blooms. From June
2021 to July 2022, we identified monthly cyanobacterial communities and estimated water nutrients,
organic carbon, temperature, oxygen, and pH. Cyanobacterial communities were dominated
by the genus Planktothrix in Lake Fortune, and this genus was in a bloom state for each
month of the year. Cyanobacterial abundance was highest (210 000 cells/mL) in November and
lowest (28 000 cells/mL) in March. The abundance of Planktothrix correlated with total nitrogen
and phosphorus and dissolved organic carbon concentrations. Planktothrix dominated even under
ice cover, because of its ability to thrive in low-light and low phosphorus conditions. In Lake
Beauchamp, Aphanothece was found throughout the year, highest (27 800 cells/mL) in August and
lowest (2100 cells/mL) in March. In Lake Beauchamp, cyanobacterial blooms correlated with
total dissolved phosphorus, nitrogen and organic carbon concentrations during summer and fall.
The dominance of Aphanothece was especially pronounced during the summer and fall. Our study
provides new knowledge about the seasonal dynamics of cyanobacterial blooms to help guide the
future management of HABs in boreal lakes.},
organization = {This project was funded by grants from MITACS obtained by GG and MMG. Part of the project was funded with a grant from the Fondation UQAT (FUQAT) obtained by GG and MMG. The part of the project focused on Lake Beauchamp was funded through a grant from the Ville d’Amos obtained by GG. Cyanobacteria sample analyses from Lake Fortune were funded by the Ministère de l’ Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs. Part of the equipment was provided by a FCI grant – SmartForest.},
publisher = {Elsevier},
title = {Cyanobacteria in winter: Seasonal dynamics of harmful algal blooms and their driving factors in boreal lakes},
doi = {10.1016/j.heliyon.2024.e40687},
author = {Grosbois, Guillaume and Anjum Mou, Tasnim and Montoro Girona, Miguel},
}