With inland water temperatures rising and aquatic plants emerging, the Delaware Department of Natural Resources and Environmental Control’s Division of Fish & Wildlife will begin annual treatment of downstate public-access ponds for nuisance aquatic weeds.

These nuisance weeds, if left unchecked, can choke the water they’ve invaded, crowd out beneficial plant species and prevent fishing and boating access. Ponds to be treated are Tubmill Pond near Milford, Wagamons Pond in Milton and Millsboro Pond.

Hydrilla, a nonnative plant that likely entered the state through the aquarium trade, is the primary target of the treatment. The Division of Fish & Wildlife’s Fisheries Section is applying Sonar, an Environmental Protection Agency-registered and approved aquatic herbicide containing fluridone, to the ponds where hydrilla is widespread. In compliance with EPA guidelines, DNREC has filed a notice of intent to use Sonar and has submitted a pesticide discharge management plan to the EPA.

Sonar has been used in Delaware since the 1980s and has proven environmentally compatible and effective for controlling hydrilla. Sonar does not pose any threat to wildlife, including fish.

Signs are posted in the boat ramp area of each pond on the day of treatment. The only special precaution for residents is a 30-day restriction from the date of treatment on water use from the ponds. Residents who live alongside the ponds and those directly downstream should not use pond water to irrigate their gardens, yards or agricultural lands for 30 days after treatment to avoid possible damage to their plantings.

To prevent the spread of invasive aquatic vegetation to other ponds and waterways, anglers and boaters are encouraged to remove hydrilla and other aquatic plants from their boats, trailers and gear before leaving the boat ramp area, Clark said.

In the case of state-managed ponds used for crop irrigation, farmers who irrigate from them are contacted prior to treatment to ensure that the 30-day after-treatment water-use restriction will not negatively impact their agricultural activities. In some cases, Fish & Wildlife-managed ponds cannot be treated due to agricultural water needs.

The Division of Fish & Wildlife treats state-managed ponds that allow public access for anglers because the treatment work is funded through the Federal Sport Fish Restoration Program and state fishing license funds. While the Division of Fish & Wildlife does not treat private ponds, it can provide a list of businesses licensed in Delaware to treat nuisance aquatic weeds.

For information on treatment of state-managed ponds, call 739-9914.