Fisheries Conservation photo

It hasn’t even been two years since we all were made aware of Didymo, or rock snot, an invasive species that has been raging across New Zealand and which has now found its way into famous trout stream in the Northeast U.S. — including the Battenkill in Vermont, the East and West Branches of the Delaware River, and now Esopus Creek in the eastern Catskills of New York.

I’m no scientist, but from what I understand, Didymo is this mucous-like algae that grows rapidly along stream bottoms, essentially choking out all life forms that live on the bottom. To fly fishermen, this is especially worrisome: No aquatic insects eventually will mean no trout, dead waters, the end of fishing as we know it.

Biologists says that Didymo can be carried from one stream to another in the felt on the bottoms of your waders. To fight this, they recommend getting rid of your felt-soled waders and replacing them with rubber-soled boots. They also recommend cleaning and thoroughly drying your boots after every fishing trip.

No one has recommended this, but if practical, you could actually keep your felt-bottomed waders so long as you only used them in one stream, and didn’t take them to another. This would mean owning multiple pairs of wading shoes. But Didymo can travel on the outsides of your breathables, in your streamers and dry flies, and just about anywhere else.

Go to and click on the latest Didymo article. Seems like pretty serious stuff to me. Am I right, or are some people saying that the sky is going to fall in.

Anyone have other ideas on how to prevent this stuff from spreading? — Jay Cassell