Clean all gear when moving between waterways.
Freshwater pests, including didymo, could squeeze the life out of our region’s precious rivers and lakes. They can be spread by a single drop of water or plant fragment. You can help to protect your favourite waterways if you always check, clean then dry any equipment that comes into contact with the water, between every waterway, every time.
Check, Clean, Dry
When moving between waterways, whitebaiters, anglers, kayakers, trampers and other
- Check anything that has been in contact with the water. Remove any debris or plant matter.
- Soak or scrub equipment, including boat and trailer, with decontamination solution (5% dishwashing liquid or 2% household bleach) for at least one minute. Make sure each item is fully wet. Special attention should be paid to the jet boat grate, outboard motor, bilge pump, mats and carpets.
- Alternatively, completely dry items to the touch, both inside and out, and then leave for a further 48 hours to ensure any invisible pests, including didymo cells, are completely dead.
Freezing any item until solid will also kill didymo. If cleaning or drying is not practical, restrict equipment to a single waterway.
Felt-soled waders & absorbent items
Felt-soled waders require soaking for at least 40 minutes in hot water kept above 45C, or soaking for 30 minutes in hot water kept above 45C containing 5% dishwashing detergent or nappy cleaner. Rubber-soled footwear is easier to clean and dry.
Absorbent items require extra treatment, either with prolonged soaking in water heated to 45 degrees or above, or by being frozen solid. People who hold fishing licences are banned from using felt-soled waders or wading boots when angling for sports fish such as trout. The ban applies throughout New Zealand, including the Taupo fishery.
Whitebaiters should note that although salt water will also kill didymo cells, seawater in whitebaiting areas is ineffectual because it is too diluted. Whitebaiters can prepare a 2% salt solution (saltier than seawater) by adding a small cup (200 ml) of table salt to water to make 10 litres. Soak equipment for as long as it takes to thoroughly saturate the item, plus at least an additional 10 minutes.
Why it’s worth the effort
Following the Check, Clean, Dry procedure helps reduce risks to our waterways.
Hornwort poses a serious risk to Taranaki lakes due to its ability to rapidly invade freshwater habitats, crowding out native species and impeding drainage and flow. Since its discovery in Lake Rotorangi in 2012, there has been a high risk of hornwort spreading to other lakes in the region, especially other popular boating locations.
Didymo, an invasive and unsightly algae, is currently widespread through the South Island. Help us to keep it out of our Taranaki waterways.
Other threats to our waterways are Lagarosiphon oxygen weed and Egeria oxygen weed. They both spread rapidly and are difficult to eradicate.