Vallisneria, commonly known as eelgrass, is an important aquatic plant found in many freshwater lakes across North America. This submerged plant plays a vital role in lake ecosystems, providing numerous benefits to water quality, wildlife, and even recreational activities.

Characteristics of Vallisneria

Vallisneria is a perennial, submerged plant that typically grows in shallow waters ranging from 2 to 18 inches deep. It has long, ribbon-like leaves that can reach lengths of several feet, though in most lakes, it tends to grow much lower. These leaves are flexible and move gracefully with the water currents, allowing Vallisneria to avoid becoming a navigational obstacle in most areas of the lake.

Unlike more invasive species such as milfoil or elodea, Vallisneria doesn't form dense, surface-reaching mats. Instead, it grows in low clusters, which makes it an excellent plant for maintaining water quality and promoting healthy ecosystems without interfering with recreational uses like boating, fishing, or swimming.

Ecological Benefits

1. Improving Water Quality: Vallisneria helps stabilize the lakebed, preventing erosion and reducing the amount of suspended sediment in the water. Its roots anchor the soil, while its leaves absorb nutrients that would otherwise contribute to algae blooms. By competing for nutrients, Vallisneria plays a role in controlling excessive algae growth, which can lead to clearer, healthier water.
2. Habitat for Wildlife: The plant provides essential habitat for fish, invertebrates, and other aquatic life. Small fish use the dense vegetation as shelter from predators, while the plant’s leaves offer surfaces for beneficial microorganisms to thrive. Vallisneria also serves as a food source for waterfowl and some fish species.
3. Supporting Biodiversity: As a native species in many North American lakes, Vallisneria helps support a balanced ecosystem. Its presence encourages biodiversity, as it supports various species of fish, amphibians, and other wildlife that rely on submerged vegetation.

Vallisneria vs. Invasive Species

One of the standout benefits of Vallisneria is its ability to occupy space in a way that reduces the potential for invasive species to establish themselves. Unlike milfoil or hydrilla, which can spread rapidly and form dense mats, Vallisneria grows at a slower rate and maintains a more contained presence in the lake. Its moderate growth helps preserve open water areas for recreation while still providing ecological benefits.

Managing Vallisneria in Lakes

In most cases, Vallisneria is considered a beneficial plant that requires little to no management. However, in lakes where it becomes overabundant, mechanical harvesting or selective removal may be necessary to maintain a balance between vegetation and open water. Since Vallisneria primarily grows in shallow areas, it’s essential to monitor its spread to ensure it doesn’t hinder access to docks, boat ramps, or other high-use recreational spots.

Conclusion

Overall, Vallisneria is a key player in maintaining the health of North American lakes. Its ability to improve water quality, provide habitat for wildlife, and support biodiversity makes it a highly valuable plant in lake ecosystems. As the dominant aquatic weed in many lakes, including those where invasive species pose a threat, Vallisneria is a natural ally in promoting a balanced, healthy aquatic environment.

For lake residents and recreational users, this low-growing plant is often a welcome presence, as it supports the lake’s health without causing the issues associated with more aggressive aquatic weeds.