650007924, To prevent snot-like blooms spreading around a national park, visitors are being asked to clean their kit.

The Department of Conservation (DOC) is calling on people visiting Nelson Lakes National Park this summer to use new cleaning stations set up to combat the spread of invasive algae in the parks’ lakes and rivers.

Microscopic algae species lindavia and didymo, which could produce snot-like blooms, have been found in Lake Rotoiti, Lake Rotorua and Lake Tennyson, and in some Tasman and Marlborough rivers.

DOC want people to check, clean and dry gear that has had contact with fresh water before using it in other lakes and waterways, and those headed to Nelson Lakes National Park are being asked to clean gear that is wet or damp from any lake or river at the cleaning stations.

DOC Nelson Lakes senior biodiversity ranger Melissa Griffin said gear needed to be soaked for 10 minutes in detergent solution at the cleaning stations to kill the microscopic algae.

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

Lindavia was known to cause a sticky mucus-like substance known as ‘lake snow’ that appeared below the water surface, and didymo, also known as ‘rock snot’, could form in large quantities on the bottom of lakes and rivers.

Cleaning stations were located near main access points at Coldwater, Lakehead and Sabine huts, and for the third summer, hut wardens would be based at Blue Lake Hut to speak with trampers about preventing the spread of algae and aquatic pests.

Respecting the sacredness of Rotomairewhenua/Blue Lake and Rotopōhueroa/Lake Constance, tapu to mana whenua iwi, particularly to Ngāti Apa ki te Rā Tō, was another topic hut wardens would talk about with visitors.

People would be asked not to touch the water or swim in those two lakes to uphold their mauri/life force and pureness.

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

“As lindavia and didymo are microscopic they are hard to detect unless multiplied in a bloom. When they’re not blooming, people won’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.”