With an increased number of people using the region’s lakes, rivers and streams over the hot summer months, Otago Regional Council and the Ministry for Primary Industries are reminding residents and visitors to clean their equipment between waterways to avoid the spread of unwanted freshwater pests.
Freshwater pests such as invasive algae didymo, lake snow, and hornwort pose a serious threat to our waterways.
“Once in a waterway they can disperse rapidly and destroy the environmental, recreational and aesthetic values of our waterways,” ORC acting director environmental monitoring and operations, Peter Winder, said.
The South Island is a controlled area for didymo which makes it a legal requirement to clean all water gear before going from one body of water to another.
Anything that has made contact with water, including togs, fishing lines, footwear and boats should be cleaned for at least one minute with a five percent solution of biodegradable dishwashing solution. Water absorbent materials such as lifejackets, wetsuits and boots require longer soaking times to allow thorough saturation.
“We ask people going between waterways to Check, Clean, Dry any equipment that has come into contact with river or lake water. Some freshwater pests, like didymo, are microscopic and can be spread by a single drop of water. Even if you can’t see the danger you could be spreading it.”
Winder said before leaving a waterway, everyone should check their items for any weed or debris and leave it at the waterway they found it in.
Don't wash plant material down any drain.
Drying will kill didymo, but even slightly moist items can harbour didymo and other microscopic pests for months. To ensure didymo cells are dead by drying, the item must be completely dry to the touch, inside and out, then left dry for at least another 48 hours before use.
Winder said, “Following these simple procedures will help slow freshwater pests like didymo from spreading throughout New Zealand waterways. It’s everyone’s responsibility to try to preserve the environmental integrity of our waterways for future generations.”