Didymo may be more of an eyesore than despoiler of watersheds

The latest issue of the US Fish & Wildlife magazine, “Eddies” is devoted completely to aquatic invasives. Not just the standard fare we’re used to seeing, but many of the plants that are causing issues for the deep South and Texas.

Now that the fissures in rubber shoe soles are being blamed for seed travel, and once you’ve glimpsed the effect of Giant Salvinia or Water Chestnut on a waterway, you wonder how much longer they’re going to let us get in the water, period.

There was a hint of good news, however. Our old pal Didymo may not be as bad as first thought, given that the biosecurity professionals in New Zealand have not detected any benthic “dead zone” caused by the diatom smothering the river bottom;

In spite of widely held presumptions that didymo “smothers” invertebrate populations and therefore harms fisheries, research has proven the opposite. “That’s what the prediction was,” says Vieglais, “but our results proved otherwise and the fact that there has been no collapse of the New Zealand trout fishery since didymo arrived bears that out.”