Didymo, one of several invasive aquatic pests, threatens the beauty and health of all NZ’s waterway ecosystems.
Specifically, in canyons, didymo makes everything slippery and unsightly, which makes canyoning much less enjoyable. A single drop of water can spread Didymo or other aquatic pests. Once a canyon is infected, it is infected forever.
Between each canyon, we must CHECK, CLEAN, DRY our gear to avoid contaminating other waterways.
For canyoners, this means buying a big plastic tub, and soaking your gear in detergent whilst you have a beer or enjoy dinner!
What is the official way to CHECK, CLEAN, DRY?
Authorities ask us to Check, Clean and Dry our gear between waterways
- CHECK – your gear for algae or weeds, put them in a rubbish bin
- CLEAN – 10% detergent solution for 10 minutes
- DRY – your gear completely, then leave for 48hrs before use.
But the official method is difficult for canyoners, especially if you’re on a canyoning holiday trying to visit as many canyons as possible….
How can canyoners CHECK, CLEAN, DRY?
Often, canyoners want to visit as many canyons as possible during a visit to an area, which makes it impossible to achieve the 48hr dry requirement. So that means we need to clean our gear with the right amount of detergent, and leave it to soak for long enough.
- Buy a tub & dishwashing detergent
- Find the concentration & time
- Soak your gear & enjoy a beer.
Buy a tub & detergent
Most hardware stories will sell a 100L fish bin (which is fantastic for storing wet gear in your car after a canyon). Any brand of household detergent will do: get a 5L bottle which will cover you for 10 different canyons.
100L is about the right size for the standard amount of canyoning gear per person, 25L of water and enough room to slosh stuff around.
Find the concentration & time
If you’re not going to fully dry your gear, the concentration and soak time has to be right to kill the pests!
Dishwashing liquid, time taken to kill all the Didymo*
- 1% by volume (250ml or one cups in your quarter full 100L tub) takes 100 minutes
- 2% by volume (500ml, or two cups in your quarter full 100L tub) takes 10 minutes
- 5% by volume, (1L quarter full 100L tub) only takes 1 minute
- 10% is the official recommendation ( 2L in your quarter full 100L tub), which is an impractically huge amount of detergent…
* Studies on the survivability of the invasive diatom Didymosphenia geminata under a range of environmental and chemical conditions. NIWA December 2006 – page 62 – download PDF
Soak your gear and enjoy a beer
When you get back from a trip, 1/4 fill your tub with water, put in your gear and the right amount of dishwashing liquid.
We suggest that 2% (500ml or two cups) is a practical amount to ensure the didymo is killed.
Give everything a really good squish around, then go away and have a shower, drink a beer, make dinner, sort your photos, set up a washing line etc.. Every now and again, go and agitate the tub.. Maybe between each beer…
After soaking for more than the minimum amount of time (at least an hour) hang everything up, congratulate yourself and sleep easy!
When you are heading back home (overseas, or to the north island) allow a full afternoon to dry your gear.
The last day before travelling, needs to be a cleaning/drying day.. As well as cleaning your gear, you really do want to dry it fully before heading home. Get a clothes line (your canyon rope) and dry/rotate your gear whilst you sit in the sun, read a book and enjoy a relaxing end to a great trip.
Any country with strict Biosecurity control is going to want to clean your gear if there’s the slightest hint of it being damp. Take a video of you cleaning your gear, quote the right concentrations and times and you might avoid a big delay at the airport!
You really really really don’t want Didymo to spread to your home canyons…
PLEASE ensure you do your part, it only takes a moments carelessness to alter a watercourse forever. There is no known way to remove didymo completely once a water way is infected.