What are those black spikey things on the beach?

Water Chestnuts... and you definitely do not want to step on one of these!

This is the fruit of the European water chestnut, Trapa natans. Also known commonly as devil pods, they float and can be found up and down the Hudson and less frequently on area beaches. The plant is a fast spreading invasive. They have been used for food and medicinal purpose in Europe for 5000 years or more. Strangely, they are becoming rarer and rare there, while flourishing here.

"What is this?" Is a common question we get at beach cleanups when a someone hands me a water chestnut. The water chestnut, dark in color and full of pointy spikes, triggers the imagination like few other objects which appear on our beach at Beczak. "Could it be a sharks tooth, or maybe an egg?" "How did it get here?"

While the story of the water chestnut isn't quite as exciting as what it generates in our minds, it is still an interesting find. The species that we see on our local beaches is the European water chestnut (Trapa natans). This invasive plant found its way into the Hudson River in 1884 possibly as an introduced source of food for waterfowl or an escaped plant from a water garden. It started showing up at surrounding beaches thereafter. The water chestnut grows in fresh water and may quickly overspread native plant species. This has the potential to alter the Hudson River ecosystem.

If the water chestnut grows in fresh water, how do we find the nuts here in Long Beach in salty water? The answer is simple - the tides. In fact, the tides will carry the floating chestnuts all the way to the beaches of Sandy Hook, NJ where swimmers will painfully step on them. Consequently, the locals like to refer to them as Devil's heads!

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