Grosbois, Guillaume, Anjum Mou, Tasnim et Girona, Miguel Montoro (2024). Cyanobacteria in winter: Seasonal dynamics of harmful algal blooms and their driving factors in boreal lakes. Heliyon , 10 (24). Article e40687. doi:10.1016/j.heliyon.2024.e40687 Repéré dans Depositum à https://depositum.uqat.ca/id/eprint/1759
Le plein texte n'est pas disponible pour ce document.Résumé
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-Témiscamingue (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.
| Type de document: | Article |
|---|---|
| Informations complémentaires: | La version officielle de cet article a été publiée dans la revue Heliyon en 2024. Le texte intégral de l’article est disponible en libre accès sur le site de la revue : https://doi.org/10.1016/j.heliyon.2024.e40687. |
| Mots-clés libres: | Boreal lakes; Harmful algal blooms; Ice cover; Phosphorus; Winter bloom |
| Divisions: | Forêts |
| Date de dépôt: | 04 mars 2026 16:27 |
| Dernière modification: | 04 mars 2026 16:27 |
| URI: | https://depositum.uqat.ca/id/eprint/1759 |
Gestion Actions (Identification requise)
 |
Dernière vérification avant le dépôt |