The rich soil, sunlight, and—of course—water found in Lake Hopatcong are working against you, Aqua Cleaner Environmental CEO Jerry Davis told a crowd of more than 20 lake residents on Tuesday evening. “The reality is, there’s no miracle cure,” Davis said. “Aquatic plants are going to grow and they’re going to flourish.” How to do battle with those flourishing plants that have taken over swimming areas and boating channels was the center of discussion at the weed management seminar at Lake Hopatcong Marine in Woodport on Tuesday. The event was organized by Esther Poulsen and was mostly attended by her fellow Bright’s Cove residents. It included presentations by Chris Hanlon, a biologist with Aquatic Technologies—an aquatic vegetation control company—and by Davis, whose company focuses on waterfront restoration. Each gave detailed descriptions of the options available to residents who want to keep the weeds at bay. Specifically, the presentations focused on methods that involve raking out the weeds and sediment, killing aquatic plants with chemicals, and using a specialized suction harvesting way of dredging out sediment and plant matter. Hanlon first outlined the biology of the various plants found in the Lake Hopatcong, from the milfoil (“the worst to harvest,” he said, because they regrow so easily) to the coontail (you want to manage it before it creates its own barrier to herbicide, he said) to the pondweed (“a great species to have for a balanced ecosystem,” but “can be a nuisance in shallow coves”). He pointed out that a healthy lake environment still incorporates aquatic plants; however, “the plant growth here [in Lake Hopatcong] can be astronomical… and the guys you want don’t take over a whole area.” There are four ways to handle weeds, Hanlon said: physically (using hand cutters or rollers or laying down a benthic barrier), which can be labor intensive for short-term results; mechanically (such as hydroraking or harvesting); biologically (introducing controls such as weed foragers or bacteria); or chemically (using aquatic herbicide products). Expanding on the latter three, Hanlon said his company offered options to lake residents. Mechanically, Aquatic Technologies uses a hydroraking system, which is designed to pull out plants and aquatic debris and results in less regrowth. “This machine is perfect for Bright’s Cove and small cove areas,” he said. “The material is gone, and you’re getting rid of the sea bed and remaining organics [that support weed growth], and gaining depth.” It also works along shorelines, Hanlon said. Places it will not work include rocky, stumpy areas, because the machine can’t maneuver properly. And some residents might be concerned about the potential for some small fish to come up with the weeds. Hydroraking operates from less than 1 foot in depth to 12-foot depths, and doesn’t require a permit. Another mechanical approach is harvesting, which the Lake Hopatcong Commission uses when the funding is available. Hanlon was critical of that approach, because it is not selective, cutting native and non-native species, and captures a large amount of fish. “It amazes me that fishery biologists focus on this as the tool for Lake Hopatcong,” he said. “It’s mind boggling, the number of fish that get caught up in the weed bed. But [the harvesters are] awesome for pulling up a lot of plants at a time.” Biologically, Hanlon said there are a range of species that can be introduced to the lake ecosystem to fight the weed growth. For example, certain foraging fish (such as a type of carp that was introduced to Lake Musconetcong) feed on weeds such as milfoil, but their introduction can be expensive without stellar results. Weevils are a native species that eat and kill certain weeds, but Hanlon was skeptical about their use. He said it typically costs about $1 per weevil, and each one has to be tied to a plant by a diver, making the process labor intensive and expensive. As for introducing certain bacteria and enzymes to fight the weed growth, Hanlon said he has never seen them work effectively. And barley straw—which he says is a farmer’s trick—merely inhibits growth, likely by releasing an enzyme, rather than killing the plants that are already there. The most typical method to be used by residents on Lake Hopatcong, Hanlon said, is the use of aquatic herbicide products. There are two ways to release such herbicides: systemically and with direct contact. Systemic herbicides can be more effective, he said, but added that challenges come in a large body of water like Lake Hopatcong because the chemicals can easily become too diluted. Also, it usually takes at least a month to start to see results, which might not fit a particular client’s needs or goals. Hanlon said he had talked to state legislators about using such a method in a large-scale approach on the lake, but met resistance. “The state will not pay for herbicides,” he said. “The rest of the nation deems it a management tool for weed management, but the state of New Jersey doesn’t see it that way.” The contact approach is more typical on the lake—in that case, the specialist destroys the plant at the contact site and kills the plant tissue with a fast reaction time. The advantages are quick results and lower cost. “Aquatic herbicides are hands down the least expensive way to go on a per-acre rate,” he said. The downsides? Some people are averse to using chemicals, and the organic material remains on the lake bed. Following Hanlon’s presentation, Davis of Aqua Cleaner Environmental spoke to the group about his company’s unique approach to weed removal: a method called suction harvesting that uses a vacuum-like hose, operated by a scuba diver, to take out plants, rooting systems, and all organic matter that accumulates on the lake bottom. The approach is popular in New England states and earned the company a spot on the Discovery Channel’s “Dirty Jobs” program (which is how Poulsen discovered the company). “We’re bottom dwellers,” Davis said, and detailed how each diver will carefully use the suction hose to remove overgrown vegetation, plant by plant. The level of detail is evidenced by the fact that the company has been called upon to find bodies and weapons for law-enforcement investigations—but more commonly retrieves sunglasses, cell phones, tools, keys, and other items that homeowners typically lose off their docks. By completing a spot dredging project with suction harvesting, Davis said, homeowners can reclaim the natural lake bottom, remove the accumulated material, and reduce the instances of algae blooms. Unlike large-scale dredging efforts, this method uses very small pumps and is very specific with its target. “We can manage what we move because we don’t move a lot.” What material is moved out is directed toward bags—smaller mesh-like bags for large plants and sticks, and a large black balloon-like bag that sits on shore and fills with sediment and muck. (For large-scale projects, the bag can be 100 feet by 30 feet, and 7 feet high; or smaller projects would use 15 foot by 15 foot bags.) A felt-like blanket is laid out underneath to further strain the water as it slowly leaks out of the bag. Once most of the water has escaped through the benthic barrier, what’s left “looks like a giant dried-up brownie,” Davis said. That material can be used for fertilizer (which Poulsen said a local landscaping company is interested in taking), and the bag can be reused as a benthic barrier on the lake bottom in a swimming area. The method is most cost effective among a group of homeowners, Davis said, and the cost depends on how much material is removed and how long it takes. He said typically his workers can complete 10 to 15 cubic yards per hour, and the average small-scale project would take a day or less. The approach is particularly useful in boathouses, because the equipment is small and portable and can go inside, and is a good choice for shoreline remediation. At the end of the event, Poulsen said she was happy with how the presentations went. “It was very informative, and we’ll see what happens from here,” she said. “Our group is planning to meet and we’ll see what the next steps will be.” Hanlon said he understood that people have had it “up to here” with the weed problem. “It’s really impressive to see someone like [Poulsen] set up a meeting like this and educate a group of people.” Donna Templeton of Lake Hopatcong agreed. “The whole thing was very interesting,” she said. “It was extremely helpful—and hopeful.” For information about the companies, visit www.aquatechnj.com or www.aquacleaner.com.