Didymo (Didymosphenia geminata) is an invasive freshwater algae which is present in some South Island rivers in New Zealand. Didymo is most likely to be spread by humans moving items between waterways.
To ensure you don’t spread didymo, wherever possible restrict equipment, boats, clothing and other items for exclusive use in one waterway.
For more information on didymo read our About Didymo PDF Factsheet.
Also see our Felt Soled Waders Restrictions FAQ page for more important information on equipment restrictions.
You can read about the latest Didymo information by visiting the Didymo page on the New Zealand Biosecurity website.
Attention Fiordland Anglers: Any person wanting to fish on almost all of Fiordland’s rivers and lakes is required to obtain a Clean Gear Certificate for all gear. To read about this and other special conditions which apply to Fiordland National Park, click here.