Didymo is an invasive aquatic pest, that threatens all of NZ’s waterways. http://www.biosecurity.govt.nz/pests/didymo

A single drop of water can spread this terrible pest, so Canyoners must be extremely vigilant to CHECK, CLEAN and DRY their gear in accordance with the direction on the biosecurity website.

Research demonstrates how important it is to use the correct concentration of cleaning agent. (see page 62 of the report)

Didymo is not the only pest that threatens our waterways. The Biosecurity website has more information. Also, the National Institute of Water and Atmospheric Research (NIWA) has an information page about the many unwanted plant species.

By awareness of the risks and application of CHECK, CLEAN, DRY we can keep our canyons pristine for all to enjoy.

How do we practically do this if we are doing more than one canyon in a trip, and we don’t have enough time to dry our gear?

MPI recommends that everything that comes into contact with the water has the CHECK, CLEAN and DRY routine before heading to another waterway.

However, if there’s not enough time to fully dry, inside and out, then leave for another 48hrs, MPI says that CHECK and CLEAN is acceptable.  (see the protect your patch booklet)

So practically, you go to a hardware store, buy a 100L fish bin (which is fantastic for storing wet gear in your car after a canyon) and a 5L bottle of household dishwashing liquid.

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.

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. 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.. Then when you’ve done all that stuff, hang up your gear somewhere the sun and wind can get at it.  Every now and again, go and agitate the tub.. Maybe between each beer…

Then when its been soaking for the right amount of time (like a couple of hours) hang everything up, congratulate yourself and sleep easy!

If you’re not completely drying your gear, then the cleaning has to be excellent. You need to use the right amount of cleaning product (its more than you think) and leave it for the right amount of time.  (See page 62 of the report, summarized below)

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, which is what they say on the brochures, requires 1L of detergent in that quarter full 100L tub!  Thats huge amounts of detergent, but it only takes 1 minute

When you are heading back home (overseas, or to the north island) budget in a full summers 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 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.