Author(s): Lengyel, E., Zsuga-Biró, Rita (R.) & Hubai, K.
Title: Physiological and ecotoxicological effects of glyphosate on the green algae Raphidocelis subcapitata
Year: 2025
Volume: 56
Pages: 141-154.
DOI: https://doi.org/10.17110/StudBot.2025.56.1.141
Abstract: Glyphosate is the world’s most widely used herbicide, yet its effects on aquatic ecosystems – especially microalgae – remain poorly understood. This study investigated the physiological responses (photosynthesis, chlorophyll-a and pheophytin content, nitrogen and phosphorus uptake rates, optical density, protein content, and stress enzyme activity) of Raphidocelis subcapitata, a standard OECD test species, to a range of glyphosate concentrations (0.45–7.2 μg L–1) over 14 days. Results showed that glyphosate significantly influenced several parameters, including reductions in photosynthetic activity and nutrient uptake rates, alongside increased oxidative stress responses at higher concentrations. At low concentrations (≤ 0.9 μg L–1), signs of hormesis were observed, with elevated photosynthesis and chlorophyll-a content. Principal component analysis revealed clear separation of treatment groups based on glyphosate levels and exposure time. The findings supported species-specific and dose-dependent effects of glyphosate on freshwater
algae, and emphasised the ecological vulnerability of shallow water bodies, such as Lake Balaton, to herbicide contamination. The results highlight the necessity for a stricter monitoring system, and further research on the chronic low-level impacts of glyphosate, as well as the development of environmentally safer alternatives. Present paper was inspired by Professor Judit Padisák, who has been a committed and unwavering advocate of Lake Balaton research from the beginning of her scientific career to the present day.Keywords: glyphosate, herbicide, microalgae, physiology, toxicology
Subject: biology, ecology, botany
Journal: Studia botanica hungaricaJournal abbreviation: Studia bot. hung.ISSN: 0301-7001Publisher: Hungarian Natural History Museum, BudapestEditor(s): Papp, B., Buczkó, K., B-Béres, V. & Stenger-Kovács, Cs.