a small eutrophic lake covered with flowering algae lemna and wolffia

rootless duckweed stagnant freshwater pond wolffia alga algae aquatic plant plants araceae floating fresh green background invasive species lake leaf lemnaceae petal seaweed stratiotes surface swamp tiny water macrophytes small ecosystem photosynthesis reproduction habitat biomass production oxygen generation chlorophyll eutrophication biological filtration density ecological role pollution algal blooms propagation wetland carbon sequestration biodiversity