Boating on lakes and harbours this summer? Five things you need to know about the invasive freshwater clam (Corbicula) if you are moving your boat between freshwater and salt.

Photo / Mountains to Sea Conservation Trust

They are fast breeders each producing up to 400 juveniles a day or 70,000 a year (WTF!)
They can survive in freshwater and brackish water, like we get in some of our estuaries and harbours
Juvenile clams are smaller than a grain of sand - too small to see and hitchhike on our boats, wetsuits and other gear.
To stop the spread Biosecurity New Zealand have introduced specific treatment requirements for boats and gear leaving places where the clams have been found.
If you find freshwater clams outside known areas do not move them, take a photo, note the location, and report it to MPI.