The world is shrinking! We are a society of outdoor recreation and as humans we love water. Today, when we can easily toss a canoe or a kayak on top of the car and move about to more and more rivers with more and more launch sites, we see increased numbers of people using the waters. Fishing is easier with greater access and with the ability to fish the waters of Vermont today and wet a line in New Zealand tomorrow, it is safe to say that the world is getting very tiny.

With this ease of access and increased activity comes dangers, the threat of the spread of invasive algae. Milfoil is one that at least here in the Northeast, we have been dealing with for a few years now but we have another one just confirmed in the Connecticut River. Didymo, or Didymosphenia geminata or “rock snot”, has been confirmed in the Upper Connecticut River. It was first discovered by a river guide, Lawton Weber.

Didymo is bad news!

It will destroy the fish and most other living creatures in our waters. How it got here remains a mystery but it can easily be spread. It can be carried from one water body to another by getting on boats, boots, gear, equipment, birds, animals and even heavy winds.

Word is spreading rampant across the Internet as people, especially fishermen, are angry and scared. On Saturday, a post was made at the Fly Fishing in New Hampshire website about the discovery.

Butch Moore, owner administrator for New England Outdoor Voice, notified me by email so that I would know about this. Butch has mounted his own campaign to inform his readers and spread the word about what to do to avoid spreading the stuff.

The Fly Fishing in Maine website, has a post at their forums discussing the event as well. This method of communication and education should help to spread the word quickly. I have read where some have already begun putting up signs at boat launches and passing out information to people in and around the rivers.

A report today in the Times Argus says that there is a possibility that a second case of didymo has been found in the White River in Bethel, Vermont.

The best way to avoid the spreading of the invasive algae is by cleaning and effectively killing it. Here is a suggestion for cleaning from the New Zealand government BioSecurity website. New Zealand is also dealing with this algae.

Cleaning Methods for Didymo

Didymo is a single-celled micro-organism that can spread from one river or lake to another by the movement of water, equipment, clothing and any other damp item. People and their activities are the main cause of spread.

To ensure you don’t spread didymo or other aquatic pests, wherever possible restrict equipment, boats, clothing and other items for exclusive use in a single waterway between cleaning.

If you are moving items between waterways, you must Check, Clean, Dry.

CHECK: Before you leave a river or lake, check items and leave debris at site. If you find any later, treat and put in rubbish. Do not wash down drains.

CLEAN: There are several ways to kill didymo. Choose the most practical treatment for your situation which will not adversely affect your gear.

* Non-absorbent items
o Detergent: soak or spray all surfaces for at least one minute in 5% dishwashing detergent or nappy cleaner (two large cups or 500 mls with water added to make 10 litres); OR
o Bleach: soak or spray all surfaces for at least one minute in 2% household bleach (one small cup or 200 mls with water added to make 10 litres); OR
o Hot water: soak for at least one minute in very hot water kept above 60 °C (hotter than most tap water) or for at least 20 minutes in hot water kept above 45 °C (uncomfortable to touch).

* Absorbent items require longer soaking times to allow thorough saturation.
For example, felt-soled waders require:
o Hot water: soak for at least 40 minutes in hot water kept above 45 °C; OR
o Hot water plus detergent: soak for 30 minutes in hot water kept above 45 °C containing 5% dishwashing detergent or nappy cleaner; OR

* Freezing any item until solid will also kill didymo.

DRY: Drying will kill didymo, but slightly moist didymo can survive for months. To ensure didymo cells are dead by drying, the item must be completely dry to the touch, inside and out, then left dry for at least another 48 hours before use.

If cleaning or drying is not practical, restrict equipment to a single waterway.

This is perhaps the biggest and most serious threat to New England waters and fisheries that any of us have ever seen and we need to take it seriously. Everything and anything that we can do to prohibit the spread of this deadly algae has to be done.

Tom Remington

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