Why do we have to protect?
Didymo forms mats of brown sludge
Stewart Island/Rakiura boasts some of New Zealand's most pristine, untouched waterways that are home to some of the best examples of native fish found in the country. In fact the fish communities found here represent what would once have been found in mainland New Zealand's waterways prior to human settlement.
Thankfully, didymo and other freshwater pests have not reached the island's waterways. Should this happen the effects could be devastating and cause irreversible damage to the waterways and native species that inhabit them. Not only is didymo an unsightly alga once its microscopic cells develop into a mat of brown sludge, but it can have serious impacts on native species.
How you can do your bit
Clean, Check, Dry to help prevent the
spread of didymo and other freshwater
pests
Wet footwear, clothing, hunting gear and equipment such as kayaks, pose a risk of spreading didymo and other freshwater pests. To help keep Stewart Island/ Rakiura pest-free, please take a couple of minutes before you leave home to make sure your gear is free of these freshwater pests.
By following the approved cleaning methods you can leave Stewart Island/Rakiura just as you found it.
Disinfecting your gear
If your gear has been thoroughly dry to touch for at least 48 hours before your trip, you are didymo free. If your gear is wet or damp from contact with any river or lake, you will need to disinfect your equipment, including socks and boots.
Clean all equipment with a disinfecting solution, ensuring surface contact for one minute for non-absorbent items. Absorbent items need to be soaked to allow thorough saturation. There are a range of solutions that you can use. The most accessible is a five percent solution of dishwashing liquid, i.e. one cup of dishwashing detergent with water added to make five litres. Freezing any item until solid will also kill didymo.
Check, Clean, Dry
Stop the spread of didymo and other freshwater pests. Remember to Check, Clean, Dry all items before entering, and when moving between, waterways.