How to help stop invasive species
There is increasing concern regarding the health of New Hampshire’s waterways because more aquatic invasive plants and animals are moving northward and eastward into state waters with new infestations discovered every year. “Clean, Drain and Dry,” is an outreach message designed to educate boaters and recreationists on how to prevent the spread of these species.
Many of these exotic species were originally transported into American waterways via the bilge water of large cargo ships. Once here, they spread primarily by “hitching a ride” on watercraft and recreational gear.
Some of the animal species cannot be seen with the naked eye, particularly during early life stages, and can survive several days out of water in moist areas such as the bunk/roller areas on boat trailers, in bilge water and on various types of recreational gear.
For a number of years boat inspections at launch ramps have more or less focused on plant species. In addition to more than a dozen invasive plant species which threaten New Hampshire waters, a number of animal species are also threats. Asian clams, zebra mussels, quagga mussels, rusty crayfish, and some species of water “fleas” (which are actually tiny crustaceans), snails, fish and others have varying potential impacts to water bodies. The threats are environmental, ecological and economic. These species can potentially alter aquatic environments — physically, chemically and biologically. They can alter the species’ composition of a water body. And if established, they can be extremely expensive to manage. Several species have the capacity to seriously disrupt aquatic ecosystems. Invasive species reproduce rapidly and displace native finfish, mussel, crayfish and phyto/zooplankton species. The invasive diatom, a type of algae, known as “Didymo” (short for Didymosphenia geminata) or “Rocksnot” is more of a threat to rivers and trout streams than lakes or ponds.
Generally these species out-compete natives for food, and nesting, brooding and rearing habitat. And many have no natural predators in their new environments to keep their populations in check. When new, aggressive species enter an ecosystem, they very likely will alter food webs. In particular, disruptions at the base of food webs — in an aquatic system this would be at the planktonic level (microscopic plants and animals) — can have serious repercussions for all species in that system. If not already in New Hampshire, these species are moving ever closer.
The “Clean, Drain and Dry,” message can apply to all non-native species, including plants and animals. Good boat and gear hygiene is critical — boats and gear that have been washed with a mild bleach solution (or other solutions listed below) are less likely to spread non-natives. Cleaning water and rinse water must not be drained back into a water body.
Also, clean all fishing tackle, nets, bait buckets and other gear after use. Humans and pets are also possible vectors for the spread of some species so swim gear, wet suits and pets should also be cleaned. Make sure to drain water from boat motors, live wells, bilges, and transom wells while on land (well away from the water body) before leaving a water area. And dry the boat, trailer and gear in a sunny area or undercover before re-launching. Depending on the weather, this may require a few days.
Robert Wood is a member of the Peterborough Conservation Commission.