Aquatic Weed Identification & How to Control Them

Florida has more than 7700 ponds, lakes, and waterways and no shortage of invasive aquatic weed species. Proper management of aquatic weeds is key to keeping Florida water bodies clean and healthy. The state is home to hundreds of native aquatic plants that live in damp to wet soils and some that live in or under water.

How to identify aquatic weeds in lakes and ponds

Aquatic vegetation is a key component of a lake or pond’s ecosystem. These aquatic plants keep the water bodies healthy and maintain their aesthetic appeal. However, sometimes the management of aquatic plants is needed. Overgrowth of native plants or the presence of non-native plants can affect water quality and fish habitat, reducing the amount of oxygen in the water and creating anoxic conditions.

Aquatic weeds can spoil the look of water bodies and become an impediment to recreation on them. Problematic pond weeds identification weeds is a crucial first step. Once you know the different types of pond weeds, you can take sound measures for their management and control. Here are some common pond weeds found in Florida’s lakes and ponds and how they can be maintained via lake algae control.

Floating Plants & Algae

Floating plants live on the surface of the pond. They don’t have a root system and move around the lake or pond with the wind. They get their nutrients from the water. Free-floating plants and algae play many roles in Florida’s water bodies. They provide habitat and food for fish and wildlife and help control and reduce shoreline erosion.

Watermeal and duckmeal are common native floating plant species. They offer good habitat for insects that many fish species feed on. They can also offer a home to unwanted pests such as mosquitoes.

However, invasive non-native floating plants such as water hyacinth and even the native duckweed can multiply rapidly and are generally difficult to control. Severe overgrowth becomes infestations that block sunlight from the lakes and ponds and deplete the oxygen in them.

Algae play an important role in aquatic ecosystems. They form the food and energy base for all organisms living in lakes and ponds. However, as we know well in Florida, overgrowth of algae can cause harmful algal blooms that interfere with the enjoyment of our water bodies.

Submerged Plants

Submerged plants grow mainly below the surface, rooted in the bottom of water bodies. Most of their vegetative mass will be below the waterbody’s surface, with some portions above water. They generally grow in water under 10 feet deep, however, some grow in water as deep as 20 feet. Environmental factors such as water clarity, light, pH, temperature, nutrient availability, and sediment stability are all factors in where these plants grow.

Submerged plants play several roles in the aquatic ecosystem. Juvenile fish and small fish species hide in submerged plants for protection from predators. They help add or maintain dissolved oxygen in the water, critical to keeping a pond healthy. They also affect nutrient cycles, stabilizes sediments and shorelines, and increase water clarity.

However, if submerged plant growth gets too dense, the fish will avoid the area, the water flow will be slowed or restricted, and dissolved oxygen becomes dangerously low. This results in anoxic conditions.

Common natives submerged plants in Florida coontail, American pondweed, and elodea. Non-native species include parrotfeather milfoil and hydrilla. These non-native species grow extremely rapidly and, if not managed, can completely fill a pond from top to bottom.

Emergent Plants

Emergent plants grow in the bottom of water bodies, or in the moist soils surrounding them, with the majority of their vegetation above the surface. They generally grow around the shoreline but can extend further into the waterbody if the water is shallow.

Emergent plants grow in water about 4-5 feet deep in wetlands and along shorelines. There are also floating emergent, these plants float in on the surface, but unlike floating plants, they are rooted in the bottom of the lake or pond. Emergent plants provide habitat for wildlife, food for water birds, and reduce shoreline erosion.

Cattails, bulrushes, and maidnencane are examples of emergent plants that grow in damp soils in and around a waterbody. Aquatic grasses, sedges, and rushes such as sugarcane plume grass and giant foxtail are native plants that fall into this category. However, there are also non-native emergent plants such as torpedograss, paragrass, napier grass, and West Indian marsh grass. These plants can spread quickly and turn a pond or lake into a marsh.

Aquatic Pond Weed Control

Getting a handle on aquatic weed growth in water bodies begins before the weeds take over. There are many ways to help keep ponds and lakes healthy and aquatic plant growth, especially aquatic weeds, under control.

Below are several methods used to control algae and aquatic weed growth in water bodies.

Aeration Systems –an aeration system consisting of fountains and aerators help circulate the water and keep it oxygenated. This helps disrupt the overgrowth of algae and other aquatic weeds.

Fish Stocking – stocking a pond with native fish or specially raised, sterile Asian grass carp that feed on algae and submersed aquatic weeds. Identification of aquatic weeds is needed since not all fish species feed on all aquatic weeds.

Mechanical Harvesting – mechanical aquatic weed harvesters can selectively remove invasive aquatic plant species. This method is often used to remove large amounts of aquatic weeds or clear the way through dense vegetation without using aquatic herbicides.

Chemical Control Treatments – all chemical control methods for controlling aquatic weeds must be EPA-approved. These herbicides are specific to weed species and allow the other plants to grow. Aquatic weed species must be identified and the appropriate EPA-approved herbicide used.

Because the ecosystem of water bodies is delicately balanced, it is best to have a professional aquatic weed control service to ensure the lake or pond remains healthy. If you need professional aquatic weed management, contact Lake & Wetland today at (855) 888 – 5253 or contact us online for more information. We offer an eco-friendly & professional approach to maintaining the quality health of lakes and ponds.