The littoral zone includes the shore area of lakes or ponds and can extend into the water several feet and sometimes the entire surface of shallow water bodies. This shallow zone gets a lot of nutrients from runoff and non-point pollution, so it common in unmanaged lakes and ponds to find algae and aquatic plant growth along the littoral zone.
How much do you know about littoral zones and the role they play in a healthy lake or pond? These littoral zone facts will help you understand the value of these areas.
What Is Unique about the Littoral Zone?
This area is home to organisms that need a lot of sunlight to thrive. It extends from the shoreline into the lake until plants that require sunlight and thrive in shallow water are no longer rooted into the lake’s bottom. The water is generally shallow enough for people to wade in, and the temperature is higher than other zones in the water body.
What Lives in the Littoral Zone?
Some little-known facts about the littoral zone include what lives in this vital area. The shallow water absorbs more of the sun’s warmth, making this area home to a diverse community of organisms, including algae, floating and rooted aquatic plants, snails, insect eggs, and larvae (mosquitoes, midges, and dragonflies), fish, and amphibians. The insects and vegetation that live in the littoral zone form the base of the food chain for other animals such as snakes, turtles, fish, and waterfowl.
Because this area is nutrient-rich, diverse, and abundant, organisms thrive in the warm, shallow waters. Almost every animal in or around a lake or pond uses the littoral zone at some point, including insects, insect larvae, snails, young fish, birds, frogs, and snakes.
The littoral zone and its subzones have unique qualities and are homes to distinctive organisms. The organism that lives in each level of the littoral zone is suited to each location’s particular challenges and how close it is to land or water. For example, in areas with significant wave action, organisms can handle the daily shifts in temperature, turbulence, and predation by wildlife and aquatic animals.
Littoral Zone organisms include a wider variety and greater number of consumers than the other zones in a lake or pond. Organisms that are mobile, such as snails, amphibians, turtles, fish, and some insects, find shelter from the sun under rocks and plant cover and live almost exclusively in this area. Tadpoles are critical primary consumers of algae and other plant materials. Other animals, such as worms, take cover by burrowing into the sediment at the lake’s bottom. A variety of small crustaceans and water fleas also make this zone their home.
Perhaps the most notable organisms living in the littoral zone are the aquatic plants that rise above or float on the surface. Many plant species have adapted to being partially submerged, and others have adapted to being fully submerged. Partially submerged or emergent plants root in the water-saturated soils but grow mainly above the water. Free-floating plants are not rooted but float on or below the surface of the water.
Aquatic grasses, rushes, and sedges are also emerged plants that grow along the shores of lakes and ponds. Florida’s native grasses include sugarcane plume grass, giant foxtail, and smaller grasses such as maidencane and knotweed. Other emergent plants include arrowheads, fire flags, and viney water spinach that crawls across the water.
The littoral zone’s organisms also include submerged plants that provide habitat, shelter, and food for animals that also live there. These plants grow mainly below the surface of the water, and some are free-floating. Tape grass and hydrilla are rooted in the pond’s sediments, while bladderwort and coontail are free-floating. Sago pondweed’s branches and leaves grow just below the surface, while fanwort flowers float gently on the surface.
Plenty of fish make the littoral zone their home, including mosquito fish on the hunt for a quick meal, as well as Florida flagfish and Sailfin mollies. Dragonfly and damselfly larvae live in the zone until they climb the stalks of submerged plants, shed their shell, and emerge as adults.
Why Is the Littoral Zone Important?
The littoral zone plays a key role in the health and water quality of lakes and ponds. As the most biologically active area of a water body, it supports a large number of plant, animal, and vegetation species. Lakes and ponds with a wide variety of native plants generally offer more nutrients for native fish and wildlife to feed on.
When a lake’s littoral zone is well-vegetated with native plants excess nutrients from runoff such as nitrogen and phosphorus are effectively filtered, thus helping improve overall water quality in the lake or pond. Vegetative buffers of native plants also help to reduce erosion by creating a physical barrier along the shoreline that protects it from waves.
Additionally, littoral zone plants provide habitat and food for aquatic organisms, fish, and wildlife. Once planted, they often need very little maintenance as they are controlled by the water’s depth and the sun’s ability to penetrate it.
Protects against Shoreline Erosion
Planting native vegetation in a waterbody’s littoral zone can help control or even prevent erosion. The root structures of shoreline and submerged plants can provide erosion control. They prevent erosion with their large root systems that help stabilize the soil and reduce waves.
Balances Nutrient Absorption
By absorbing excess nutrients, littoral zone plants help balance the aquatic ecosystem and improve water quality. Pollutants from stormwater runoff often make their way into lakes and ponds, and plants in the littoral zone can absorb them, improving the water quality and preventing problems that could be caused if the pollutants became concentrated.
Maintains Aesthetics of Lakes and Ponds
Lush, healthy aquatic plants in the shallows near the shoreline enhance the appearance of any lake or pond. Native species can add year-round aesthetics and visual impact that can easily be managed and maintained.
Increases Wildlife Habitat
Native plants can bring a pond or lake to life by creating attractive and ideal habitats for animals and birds. They provide shade for fish and a place to hide from predators. They are also a food source for wildlife such as ducks, turtles, insects, fish, and wading birds. They attract insects, a food source for frogs.
How to Protect Littoral Zones
The littoral zone of a waterbody is crucial to maintaining healthy nutrient levels and aquatic organisms and wildlife. To keep this are in good shape and preserve as much of it as possible, professional littoral shelf maintenance in Florida is key. You may need mechanical removal of invasive species, treatment for harmful algal blooms, and more. Contact Lake & Wetland Management for a free on-site inspection of your lake or pond and discuss a plan to keep it healthy.