Didymo in the South Fork of the Boise River

Photo courtesy of Biosecurity New ZealandIt looks like “rock snot” has been confirmed in the South Fork of the Boise River.  In an article in today’s Idaho Statesman (click here to read the full article) Idaho Fish & Game has confirmed that Didymo, aka rock snot, has been identified in the South Fork of the Boise.

F&G biologist Jeff Dillon noted that it could very well be a native diatom that has always been there, but it is something that they need to keep an eye on.

With all the invasive species (didymo, zebra mussels, New Zealand mud snails, etc.) threatening our waterways it is very important to clean your gear thoroughly when going from one waterway to the next especially with all the Fish-Outs FFI sponsors.  It is up to us to ensure we protect the waterways that are so important to not only our sport, but everything we do.

Another thing to consider when you are purchasing your next pair of wading boots is switching to a Vibram or sticky rubber soled boot.  A number of manufacturers, such as Simms & Patagonia, are now offering these options.  Simms feels so strongly about this issue that they will be discontinuing their line of felt soled boots in 2010.

Below are instructions on how to clean felt sole wading boots & waders to prevent the spread of Didymo as provided by the New Zealand government (see more tips here).

Fishing footwear containing absorbent material, such as felt-soled waders and boots, poses a high risk of didymo transfer—these items are likely to come into direct physical contact with didymo cells (e.g., stepping on or brushing against algal mats), and the moisture retained in these goods helps cell survival.

Choose one of the following treatments specific to felt-soled waders and boots:

Hot water: If hot water alone is used, careful attention is needed to ensure the temperature of the water is maintained at no less that 45 °C for 40 minutes to ensure the interior of the felt reaches a sufficient temperature to kill all cells;


Hot water and detergent: The entire felt sole and boot needs to be completely immersed for 30 minutes in hot tap water kept above 45 °C (uncomfortably hot to touch) containing 5% dishwashing detergent or nappy cleaner;


Freeze until solid: The time required until the boot is frozen solid will vary depending upon the grade of material, how much moisture it contains and the efficiency of the freezer. Freezing overnight should work in most instances.

Drying:  Relying on ambient drying as a stand-alone treatment for decontaminating highly absorbent risk goods such as felt-soled waders and boots is not recommended in situations where use between waterways is frequent (daily, weekly or even monthly). Drying should only be relied upon as a decontamination treatment if great care is taken too actively and completely dry the felt (such as by using a heat source where temperatures around the felt are assured of reaching 30 °C). Once the felt appears dry, complete dryness must be confirmed by a tactile inspection of the felt pile to the base of the fibers. Once completely dry, items must remain dry for at least 48 hours before use in another waterway.

These instructions for decontaminating felt soled waders and boots can be used for other absorbent materials.

If you do not want to decontaminate your gear, you should restrict use to a single waterway.

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