By John Horan
Eastman Lake provides enjoyment for us all, whether we are swimming, boating, fishing, or relaxing at the beach. To preserve that enjoyment, each of us, including our guests and renters, need to take basic precautions with the watercraft we put in the lake.
The serious problem we can all help prevent is infestation by aquatic invasive species – plants and animals not native to New Hampshire. Once infestation occurs, subsequent growth can be difficult and expensive to control, and virtually impossible to eliminate completely. This can upset a lake’s ecology, interfere with swimming, boating, and fishing, and lower property values by diminishing recreational use of the lake.
Invasive species have been found in over 80 water bodies in New Hampshire. The most common way they spread is “hitchhiking” on a boat, trailer, boating accessories, or fishing gear previously used in an infested lake or river. The species most commonly found in New Hampshire is variable milfoil. Once established in a lake, it can grow rapidly, in optimum conditions up to one inch per day, to a length up to 15 feet. It reproduces through fragmentation – plant fragments broken off, e.g., by a boat’s propeller, can grow roots and settle in new locations. New Hampshire waters lack enough natural predators to keep its growth under control.
Several years ago, heavy infestation of variable milfoil in Phillips Pond in Sandown was described as choking the lake, interfering with swimming, and bogging down boats in some places. The impact of variable milfoil may be more evident in shallow water bodies. Phillips Pond has an average depth of only 10 feet, the same as Eastman Lake.
Fortunately, Eastman Lake is still free of variable milfoil and other aquatic invasive species. But contamination may occur when boats are launched at Eastman that have been used in other water bodies. We can all help prevent that by routinely following the “Clean, Drain, and Dry” process recommended by NH LAKES (https://nhlakes.org/ education/lake-host/cleandrain- and-dry/), as described in the chart on the next page.
Lake Hosts at the boat launch at the south end of Eastman Lake routinely educate and remind boaters about the Clean, Drain, and Dry process, and help them inspect their boats and gear when launching and leaving the lake. However, residents, guests, and renters can and do launch watercraft elsewhere on the lake, bypassing the Lake Hosts. Because Eastman Lake is currently free of invasive species, the Clean, Drain, and Dry process is not needed for boats used exclusively on the lake; but whenever Eastman boats are used elsewhere, and when visiting watercraft are used on the lake, it is essential to follow this procedure. Residents can educate and assist guests and renters by providing NH LAKES information pamphlets (available this summer at the South Cove Activity Center), having an outdoor hose for their use (or, better, showing them the boat wash station on Eastman Road), and informing them that “negligent transport” of aquatic invasives violates state law (RSA 487:16-c). Only one unfortunate “hitchhiking” episode can start infestation of a lake. Let’s all work together to keep our lake clean.
More information about preventing the spread of aquatic invasive species is available at nhlakes.org/education/lake-host/.
John Horan is an Eastman resident and a volunteer Lake Host.