As the spring season progresses and temperatures begin to rise, it is a sure bet many areas will see an increase in problems associated with marine vegetation. These water-based plants, often invasive species, grow rapidly and can overtake a body of water quickly, blocking out the sunlight into the water and depleting the oxygen levels in the water. These problems affect not only people but also animals and other plants. Common freshwater plant species that can be a nuisance in the US include Water Hyacinth, Hydrilla, Duckweed, Watermeal and Giant Salvinia. These plants can overgrow rivers, streams, creeks, bayous, lakes, ponds and reservoirs.