Fiche détaillée Master
| Mémoire N° | 591 |
| Auteur | MUSCAS Irene |
| Titre | Intracellular C:P ratios and growth of freshwater phytoplankton: effects of phosphorus limitation on cyanobacteria and green algae |
| Thématique & formation | Sciences de l’eau, ressources, gestion et société (SE) |
| Résumé | Les efforts de restauration des lacs peuvent améliorer la qualité écologique des lacs eutrophes, conduisant à une ré-oligotrophisation. Il est essentiel de comprendre les impacts écologiques potentiels de l'intervention sur la charge en nutriments, la composition du seston et la communauté phytoplanctonique. La stœchiométrie écologique lie la composition chimique des organismes aux conditions de croissance, en mettant l'accent sur l'influence des nutriments comme le phosphore. La revue de la littérature explore la qualité alimentaire pour le zooplancton, sa dépendance au rapport C:P du seston avec un focus particulier sur les risques posés par les cyanobactéries. Pendant le travail de thèse, des expériences en laboratoire ont été menées avec différentes espèces de phytoplancton cultivées à des niveaux de P variés. Leur croissance a été suivie et leur rapport C:P a été mesuré à la phase stationnaire. Les données finales incluent six espèces de cyanobactéries et cinq espèces d'algues vertes. Les modèles de régression ont montré une relation négative plus forte entre C:P et la disponibilité en P pour les algues vertes que pour les cyanobactéries. Les taux de croissance ont été calculés et ajustés pour extraire les paramètres de croissance. Des résultats expérimentaux tels que ceux-ci nous aident à combler les lacunes de la littérature sur les réponses des algues spécifiques aux espèces à la limitation de P, en particulier dans le contexte de la ré-oligotrophisation. |
| Summary | Lake restoration efforts can improve the ecological quality of eutrophic lakes, leading to reoligotrophication. It is essential to understand the potential ecological impacts of intervention on nutrient loading, seston composition and the phytoplankton community. Ecological stoichiometry links the chemical composition of organisms to growth conditions, focusing on the influence of nutrients such as phosphorus. The literature review explores food quality for zooplankton and its dependence on the C:P ratio of seston, with a particular focus on the risks posed by cyanobacteria. During the thesis work, laboratory experiments were carried out with different species of phytoplankton grown at various P levels. Their growth was monitored and their C:P ratio was measured at stationary phase. The final data included six species of cyanobacteria and five species of green algae. Regression models showed a stronger negative relationship between C:P and P availability for green algae than for cyanobacteria. Growth rates were calculated and adjusted to extract growth parameters. Experimental results such as these help us to fill gaps in the literature on species-specific algal responses to P limitation, particularly in the context of reoligotrophication.Lake restoration efforts can improve the ecological quality of eutrophic lakes, leading to reoligotrophication. It is essential to understand the potential ecological impacts of intervention on nutrient loading, seston composition and the phytoplankton community. Ecological stoichiometry links the chemical composition of organisms to growth conditions, focusing on the influence of nutrients such as phosphorus. The literature review explores food quality for zooplankton and its dependence on the C:P ratio of seston, with a particular focus on the risks posed by cyanobacteria. During the thesis work, laboratory experiments were carried out with different species of phytoplankton grown at various P levels. Their growth was monitored and their C:P ratio was measured at stationary phase. The final data included six species of cyanobacteria and five species of green algae. Regression models showed a stronger negative relationship between C:P and P availability for green algae than for cyanobacteria. Growth rates were calculated and adjusted to extract growth parameters. Experimental results such as these help us to fill gaps in the literature on species-specific algal responses to P limitation, particularly in the context of reoligotrophication. |
| Volée | 2021 |
| Date et heure soutenance | 04-09-2024 |
| Salle soutenance | |
| Collation | |
| Remarque | |
| Mot-clés | Phytoplankton, lake, seston, foodweb, carbon, phosphorus, C:P ratio, green algae, cyanobacteria, re-oligotrophication, stoichiometry |
| Cote bibliothèque | |
| Stage organisme | |
| Maître de stage | |
| Projet recherche | |
| Bourse | |
| Terrain d'étude ou d'application | |
| Documents associés |
Fiche analytique Mémoire disponible sur demande |
| Dernière mise à jour |
2024-12-12 10:21:55 |