Updated: Sep 6, 2020
Plants that have adapted to living in freshwater or saltwater environments are referred to as aquatic plants. Aquatic plants can only survive when submerged in water or if the plants are growing in soil that, at all times, is saturated with water.
Symbiosis: Aquatic Plants and Fish
Aquatic plants and fish provide several benefits for each other, creating a symbiotic relationship. For example, waste byproducts that fish produce are a source of nutrients for aquatic plants. Aquatic plants create a balanced and healthy ecosystem. This is due to their abilities to reduce algal growth by absorbing nutrients, offer shade and cool water temperatures to sea creatures, provide fish with shelter and spots to hide from predators, act as a natural means of filtration by removing toxins, carbon dioxide, nitrogen and phosphates, and give off oxygen to fish and other living organisms. Evidently, aquatic plants and fish rely on each other for a safe and balanced habitat.
Types of aquatic plants
Aquatic plants are typically categorized depending on the positioning of the plant’s roots and leaves. Types of aquatic plants are floating plants, submerged plants, and emergent plants. Marginal or bog plants are considered semi aquatic plants.
Floating plants are aquatic plants which are not attached to the bottom of the water body, but have roots that drift below and absorb water, therefore acting as natural biological filters. This type of aquatic plant also offers shade for fish and a hiding place from predators. Floating plants can live in both freshwater or saltwater. Examples of floating plants include Water Hyacinths, Water Lettuce, and Giant Duckweed.
Submerged plants, often known as oxygenated plants, are plants that grow completely underwater with planted roots. These plants introduce oxygen into the water body while removing excess nutrients like nitrates and carbon dioxide from water. Similar to floating plants, submerged plants also provide a means of shelter for fish and spots to hide from predators. Submerged plants include Eelgrass, Hydrilla, and Waterweed.
Emergent plants are deep water plants with roots that grow very deep underwater and are rooted to the ground. Most of the vegetation of emerged plants, however, are above water. Flowers and leaves of emergent plants at the surface provide shade and offer hiding spots for fish. Examples of emerged aquatic plants include Water Lilies, Lotus, and Water Milfoil.
Marginal or bog plants are semi aquatic plants that grow in shallow water. These plants thrive in bogs, wetlands, or around the margins of a water body. Marginal plants remove excess nutrients from water bodies, thus improving water quality. Marginal plants include Water Irises and the Marsh Marigold.
Read our blog on Aquascaping to learn how to use aquatic plants for design!