Thousands of rivers and streams cross New Zealand, so it’s likely you’ll get wet feet on many tramping trips.

To reduce the spread of invasive species, it is important to check, clean and dry all tramping gear.

DOC has recently requested that people heading into Nelson Lakes National Park clean all gear that is wet or damp from any river or lake water. Cleaning stations are installed near the park’s main access points and at Coldwater, Lakehead and Sabine huts. 

The microscopic algae lindavia and didymo are present in lakes Rotoiti and Rotoroa and in Lake Tennyson on the park’s eastern edge. The algae are also in some Tasman and Marlborough rivers. Lindavia can produce a sticky mucus-like substance called ‘lake snow’ that floats below the water surface. Didymo, also called ‘rock snot’, can form large mats on the bottom of lakes, rivers and streams. 

“If gear has been dried for at least 48 hours and is bone dry, it is safe to use, but not if it has been dried for less time. For example, if people have swum in lakes Rotoiti or Rotoroa one day and plan to swim elsewhere the next day, their togs should be treated with the detergent solution even if dry,” says DOC Nelson Lakes senior biodiversity ranger Melissa Griffin.

“People shouldn’t wash or put anything in the lakes, including filling drink bottles. This will also help protect the outstanding water clarity of Rotomairewhenua Blue Lake, which has the clearest freshwater reported in the world,” says Griffin.

“As lindavia and didymo are microscopic they are hard to detect unless multiplied in a bloom. When they’re not blooming, people don’t know if it’s on their clothing or gear, which is why it’s so important to check, clean and dry all items that have been in freshwater before using them in another waterway or waterbody.”

Check
Remove any plant matter from tramping gear and leave it at the site or put it in the rubbish. Do not wash it down the drain.

Clean
Use 10% dishwashing detergent mixed with water and leave the item wet for 10 minutes. E.g. 250ml bottle, put in 1.5 tablespoons of detergent. For a 10l bucket, put in one litre of detergent.

Dry
Ensure your gear is completely dry to touch, inside and out, then leave it to dry for at least another 48 hours before using it again.