This herbaceous community of aquatic macrophytes occurs in lakes, ponds, and rivers. Submergent macrophytes often occur in deeper water than beds of floating-leaved or emergent species, but there is considerable overlap. Submergent marshes can also be found in deep water wetlands and flowages that have little moving water present. Water depth, water chemistry, water movement, and type of bottom material are among the key ecological factors that determine the nature of the submergent beds. The chemical nature of the water can greatly affect the types and abundance of aquatic plants present. Common or characteristic species and genera include various species of pondweeds (Potamogeton spp.), waterweed (Elodea spp.), coon-tail (Ceratophyllum spp.), slender naiad (Najas flexilis), eel-grass (Vallisneria americana), and several species of water-milfoil (Myriophyllum spp.) and bladderwort (Utricularia spp.).
Aquatic plants, including both emergent and submergent, form the foundation of healthy and flourishing aquatic ecosystems - both within lakes and rivers and on the shores and wetlands around them. They not only protect water quality, but they also produce life-giving oxygen. Aquatic plants are a lake's own filtering system, helping to clarify the water by absorbing nutrients like phosphorus and nitrogen that could stimulate algal blooms. Plant beds stabilize soft lake and river bottoms and reduce shoreline erosion by reducing the effect of waves and current.
Aquatic plants serve as spawning habitat for fish and amphibians, as shelter for various life stages of a variety of animal species, and as nesting habitat for birds. Plant beds support populations of aquatic insects that serve as a food base for other species. Healthy native aquatic plant communities also help prevent the establishment of invasive exotic plants like Eurasian water-milfoil (Myriophyllum spicatum).
