Managing Invasive Aquatic Plants in the Southeast: A Guide from Aqua Services

Invasive aquatic plants pose a serious threat to lakes, ponds, and reservoirs across the Southeast. Four of the most disruptive species our biologists frequently encounter are hydrilla, invasive eelgrass, Eurasian watermilfoil, and water hyacinth. At Aqua Services, we partner with landowners, lake associations, municipalities, and recreational facilities to protect aquatic ecosystems through science-driven control strategies. Our goal is to restore balance, support native habitats, and keep our waterways usable for recreation and enjoyment.

Hydrilla

Hydrilla is often called the “perfect aquatic weed” because of how aggressively it grows. This submerged plant forms dense mats underwater, blocking sunlight from reaching native plants and disrupting the natural food web.

Hydrilla spreads easily by fragments—meaning a small piece of stem can take root and form a new colony. Left unchecked, it can:

• Outcompete native aquatic vegetation
• Create poor habitat conditions for fish and waterfowl
• Clog boat lanes, swimming areas, and irrigation systems
• Lower dissolved oxygen, increasing the risk of fish kills
  
  

Invasive Eelgrass

Invasive eelgrass has become a growing concern throughout Tennessee Valley reservoirs. While native eelgrass can provide valuable habitat, this invasive variety grows aggressively in shallow coves and shorelines, creating challenges for recreation and shoreline access.

According to the Tennessee Valley Authority (TVA), invasive eelgrass can:

• Reduce boating access by clogging ramps and fishing areas
• Spread rapidly in shallow waters, especially under fluctuating water levels
• Form thick mats that trap sediment and alter fish spawning grounds

Unlike hydrilla, which thrives in deeper water, invasive eelgrass dominates the nearshore environment, directly impacting boaters, swimmers, and anglers.

Eurasian Watermilfoil

Eurasian watermilfoil is another highly invasive submerged plant that forms thick underwater canopies. It often grows so densely that it outcompetes native vegetation, reduces biodiversity, and interferes with fish spawning areas.

Key concerns include:

• Rapid spread from boat traffic, as small fragments can start new infestations
• Dense growth that tangles boat propellers and impedes swimming
• Reduction of open water needed for recreation and wildlife habitat

Water Hyacinth

Water hyacinth is a free-floating plant known for its large green leaves and showy purple flowers. Despite its appearance, it is one of the most disruptive invasive plants worldwide. In the Southeast, it spreads quickly across the water’s surface, forming thick floating mats.

Problems caused by water hyacinth include:

• Blocking sunlight and oxygen exchange, harming fish populations
• Obstructing boat lanes, irrigation intakes, and drainage systems
• Providing breeding grounds for mosquitoes and other pests
• Smothering native aquatic plants beneath its dense mats

Because it floats, water hyacinth can move with currents and winds, allowing it to spread rapidly across connected water systems.

Why These Plants Are a Problem

Though each of these species has unique growth patterns, they share traits that make them extremely difficult to control:

• Rapid reproduction – Spreading by fragments, rhizomes, seeds, or floating mats
• Dense growth – Crowding out native vegetation and reducing biodiversity
• Ecosystem disruption – Altering fish habitats, water chemistry, and food webs
• Recreational challenges – Obstructing boating, fishing, swimming, and irrigation

Together, these invasive plants threaten the health, access, and usability of waterbodies across the Southeast.

Strategies for Control in TN, GA, AR, and AL

Aqua Services takes an integrated management approach, tailoring solutions to each waterbody. Common strategies include:

• Targeted Herbicide Application:  Our licensed applicators use EPA-approved aquatic herbicides designed to suppress invasive plants while protecting native vegetation and wildlife. Timing treatments to the plants’ growth cycles is critical for success.
• Mechanical Removal:  Harvesting vegetation help restore access in heavily infested areas, especially where invasive plants limit boating and shoreline use.
• Biological Controls:  In some cases, sterile grass carp are introduced as a long-term tool for hydrilla. These controls must be carefully planned to avoid damaging beneficial native plants.
• Monitoring & Restoration:  Ongoing monitoring ensures invasive plants do not rebound after treatment. We also encourage the reestablishment of beneficial native plants to stabilize shorelines and support fish and wildlife.

Long-Term Management Practices

Managing hydrilla, invasive eelgrass, Eurasian watermilfoil, and water hyacinth is not a one-time fix. These plants require long-term commitment and adaptive strategies. Successful programs typically include:

• Initial assessment and mapping of infestations
• Multi-year treatment and retreatment cycles
• Habitat restoration to encourage native species recovery
• Seasonal monitoring to track plant spread and regrowth

Persistence is key to restoring healthy aquatic ecosystems.

Your Local Partner in Invasive Plant Control

For more than 40 years, Aqua Services has been helping communities across the Southeast protect their lakes and reservoirs from invasive plants. Whether you’re battling hydrilla in a fishing lake, invasive eelgrass along a shoreline, Eurasian watermilfoil in a reservoir, or water hyacinth covering the surface of a pond, our team of biologists and licensed applicators can develop a science-driven plan to restore balance to your waterbody.

Contact Aqua Services today to schedule a consultation or learn more about how we can help manage invasive plants on your property.

About Aqua Services, A Jones Lake Management Partner

Since 1983, Aqua Services has been a trusted leader in lake and pond management, delivering scientifically backed solutions to create and maintain healthy, balanced, and beautiful waterbodies. As a Jones Lake Management Partner, our team specializes in a full range of services to include algae and aquatic weed control, aeration systems, water quality monitoring, fisheries management, hydraulic dredging, invasive species control, and shoreline restoration. We work with HOAs, municipalities, golf courses, and private lake owners throughout Alabama, Arkansas and Georgia to maintain balanced and thriving aquatic environments through science-based and sustainable management practices.