You may associate them with Chinese food, but water chestnuts can play a role in your lake life, too. And not a good one.
At this month’s Lake Hopatcong Commission meeting, Doug Zellmann of Lake Musconetcong warned residents about the perils of water chestnuts in the lake environment. "It really is the most important weed to eradicate in this state," he said, citing Lake Musconetcong’s own battle with the weed.
The water chestnut is an invasive species that can take a toll on recreational lake activities: it has a blue-green leaf that rests on top of the water and is a stringy plant below that secures itself into the mud and can wrap around motorboat props until they can no longer turn.
But non-native species aren’t just a concern for those who like to cruise the lake. Because they have no natural predators in a new environment, they can take over, choking out other natural plant and animal species. The nature of water chestnut growth is such that they create dense mats at the water surface, preventing light from reaching the organisms below.
Water chestnuts in particular are problematic for lake management, because their seeds can have a 12-year life span, meaning you can kill the plants, but they will return unless you remove all of the seeds as well—and you won’t know for sure that you’ve removed all of the seeds, because some may not germinate for years. Zellmann said such an undertaking at Lake Musconetcong would have meant a $330,000 investment every year for more than a decade. "And if you don’t do the whole thing, you may as well do nothing."
Several states have made all-out efforts to eradicate water chestnuts from their shores. But the best thing to do is prevent them from making an appearance to begin with. Several southern states prohibit its sale (it is edible), and millions of dollars are devoted to its removal, particuarly in the spring, before the July seed set.
Lake Hopatcong residents and visitors can take thier own steps. If you regularly take your boat to different lakes, be sure there’s no chance you’ve carried the seed to Lake Hopatcong by emptying excess water before leaving another lake and/or entering the Lake Hopatcong watershed. And be aware of what water chestnuts look like—if you see them, be sure to report them to the Lake Hopatcong Commission or the Department of Environmental Protection, so removal efforts can commence immediately.
But feel free to order them in your chicken stir-fry. They have a sweet flavor and are a good source of potassium and fiber. (Just don’t let them leave your plate.)