I was speaking to Henry the other evening, and came to a realization that - many of us - even though we're experienced Fly Fishers - may not have been paying attention to this " Didymo Thing"

Henry and I are not insinuating that none of us know anything about this Algae.

What we are saying is:

We call it the " Didymo Thing" because it seems ( I could be wrong ) that it may not be real to a few of us - simply because - we aren't currently having any problems with this " THING " yet.

But - DO NOT UNDER ESTIMATE - this scourge.

It probably is not a question of " IF " , but when  this matte algae will invade our streams. And - our concern - if we don't take this seriously NOW.

Is that it will overtake us that much sooner.

I have a genuine concern that it COULD permanently alter trout fishing as we know it.

We don't want everyone to think we're all "Doom & Gloom" - but the reality is - at this point - there is no cure for getting rid of this species.

Below is some information - hopefully it will be helpful.

Please, Please, let's  ALL OF US work on the "Management" section together.

 

Didymosphenia geminata  (or Didymo), as it's commonly known: is a freshwater diatom which has historically been found in the cool, oligotrophic waters of northern Europe and northern North America. Since the mid-1980s, it has begun to take on the characteristics of an invasive species in its original range, and is being found in new areas. It forms massive blooms which have a range of adverse effects on freshwater ecosystems, as well as human and economic effects. There are even some historical records that indicate that this alga was present , at least to some extent in the Delaware River System; as far back as 1916. However, at this point Didymo seems to be developing an ability to adapt to different environmental factors.

Didymo attaches itself to streambeds by stalks. The stalks form a thick brown mat on rocks, plants and other materials in the water. Established mats form flowing streamers that turn white at the ends and look similar to tissue paper.

Didymo can form large mats on the bottom of streams, rivers and occasional lake edges where there is a wave action. Thick growths can adversely affect freshwater fish, plant and invertebrate species by reducing the number of suitable habitats. What this basically means: Habitats for the majority of aquatic insects that Trout feed upon could be severely affected. So much so, that as the food species decline - so go all those that feed on them ( TROUT )  !!!!

Didymo has been confused with New Zealand native alga. The main difference is - didymo does not feel slimy; didymo is strong and feels like wet cotton wool.

 

    Management information


    Cultural: Following the discovery of D. geminata in Southland, Biosecurity New Zealand released the following advice for containment of the algae:

    1. Before leaving the river, remove obvious clumps of algae, taking care to search for hidden clumps which may be obscured within compartments. Leave clumps at affected site. After leaving affected area, if you find clumps, do not wash clumps down drains. Treat them chemically or by drying as below.
    2. Soak and scrub all items for at least one minute in hot (60°C) water, a 2 percent solution of household bleach or a 5 percent solution of salt, nappy cleaner, antiseptic hand cleaner or dishwashing detergent.
    Note: For a 2 percent solution, add 200 mls to a ten litre bucket and fill with water. For a 5 percent solution, add 500 mls (two heavy cups) to a ten litre bucket and fill with water.

    If cleaning using the approved chemical methods in step two is not feasible, alternatively the infected equipment must be COMPLETELY dry for at least two days before it can be safely used in unaffected waters. Equipment that remains damp or could have pockets of trapped moisture after use will require longer drying times because the 48 hour drying time begins after dampness and trapped moisture have evaporated. Some equipment may never reach complete dryness depending upon how and where it is stored (shoes, waders, life vests, wetsuits, spray skirts, jet boat intakes, tyres, etc.) and therefore should always be chemically treated.
    Compiled by: Invasive Species Specialist Group (ISSG) with support from the Terrestrial and Freshwater Biodiversity Information System (TFBIS) Programme (Copyright statement)
  
For additional information, including photos of Didymo, visit www.epa.gov/region8/water/didymosphenia or www.dec.ny.gov/environmentdec/36890.