Didymo found near Arthur’s Pass
Environment Canterbury media release: 18th February 2025
The invasive, freshwater algae didymo, has been found recently in the popular tourist spot Te Tautea o Hinekakai/Devils Punchbowl Creek in Arthur’s Pass.
Didymo can form massive blooms on the bottom of streams, rivers and lakes, with its spread negatively impacting waterways. The blooms smother rocks and plants impacting water quality, biodiversity and economic and social values.
Principal Advisor - Biosecurity Laurence Smith says there are currently no eradication tools available for didymo.
“Didymo can be spread by a single drop of water. Even if you can't see it, you could be spreading it.
“There are many waterways in Waitaha/Canterbury that are free of didymo, so it’s important we all do our bit to protect the freshwater spaces we all enjoy.”
Check, Clean, Dry
The Ministry for Primary Industries (MPI) has declared the South Island a controlled area for didymo. This means there is a legal requirement to clean all gear used in the water before going from one waterway to another.
Laurence encourages water users to adopt the Check, Clean, Dry method before moving between waterways.
“It’s important we do our best to prevent its spread with behaviour change,” he says.
- Check: Check kayaks, footwear, fishing gear and anything else that was in the water, for any mud, dirt and debris and remove it. Leave debris at the site or, if you find any later, treat and dispose of it in the rubbish. Do not wash it down drains.
- Clean: Wash all equipment such as nets, machinery, footwear and clothing thoroughly with an appropriate decontamination solution (10% detergent for 10 minutes or 2% bleach for at least one minute in water) before putting it in any new waterway.
- Dry: If you can't clean your gear, restrict your use to a single waterway OR dry completely to the touch inside and out, and leave to dry for at least another 48 hours.
Find out more about the Check, Clean, Dry method to prevent the spread of freshwater pests.