‘Rock snot' suddenly the newest invasive concern
By Don LehmanContributing Writer
With the fight against one dreaded fisheries invader still ongoing, state officials are closely watching the appearance of another potentially devastating invasive species just a short distance from New York state.
A gruesome algae known as 'didymo' was confirmed to have made its way into two prime Vermont trout streams as of mid-July, and biologists there were warning it could devastate trout waters where it spreads.
The algae has caused huge problems in New Zealand, where it coats river bottoms and smothers aquatic life that trout depend on. It also has recently gotten footholds in some southern states and parts of Canada.
Its scientific name is didymosphenia geminata, but it's called 'rock snot' because of its resemblance to mucus and slickness when it coats river bottoms. It's apparently native to cooler, northern waters, but over the past two decades has started to expand its range.
It favors cool, fast, nutrient-poor waters, and the trout streams of the Adirondacks and Catskills would seem to be prime territory for it should it make its way west. It also spreads easily, with it taking just one cell to begin development.
New York Department of Environmental Conservation spokeswoman Lori O'Connell said the agency was aware of the arrival of the algae in Vermont, but said there has been no confirmed reports of it in New York.
Rich Preall, a DEC fisheries biologist in Region 5, said 'it would be very bad' if didymo made its way into New York's waters.
'It's a mucus-like covering that gets all over the rocks,' he said. 'It gets everywhere.'
In New Zealand, those who use waterways and don't take proper precautions to stop its spread can be fined thousands of dollars, he said.
Its arrival in New York would be another big headache for an agency still dealing with the ramifications of viral hemorraghic septicemia (VHS), a fish-killing disease that has been found in the Great Lakes system and a pair of Finger Lakes - Conesus and Skaneateles.
'We're so busy looking for VHS. Every time someone finds a dead fish the phone rings,' Preall said. 'It's one thing after another.'
Didymo was confirmed in the Upper Connecticut and White rivers in Vermont earlier this summer, the first discovery of it in the Northeast.
One guide who saw it in the Connecticut River and also had seen the damage it caused in New Zealand warned of dire consequences in an article in the July 11 Rutland (Vt.) Herald newspaper.
'It will destroy the aquatic insect population and, in turn, will destroy the wild trout population because there will be nothing to feed on,' guide Lawton Weber told the Herald.
Fisheries officials from around New England held an emergency meeting July 13 to discuss ways to stop the spread of the algae. George Crombie, Vermont's natural resources secretary, called it 'imperative' that ways be found to control it.
No predators or apparent ways to kill it have been found once it becomes entrenched in a waterway.
It sticks to boats, waders and other clothing that comes in contact with it, and can live for weeks outside of water and on clothing such as wader felt soles.
Freezing waders or using a bleach or detergent solution to kill the algae seem to be the best way to kill the microscopic didymo cells that linger on clothing or waders.
Vermont officials urged anglers and other water recreationists to institute New Zealand's recommended procedures for preventing the introduction and spread of didymo: Check, Clean and Dry.
Check: Before leaving a river or stream, remove all obvious clumps of algae and look for hidden clumps. Leave them at the affected site. If you find any later, do not wash them down drains; dispose all material in the trash.
Clean: Soak and scrub all items for at least one minute in either hot (140 degrees F) water, a 2 percent solution of household bleach or a 5 percent solution of salt, antiseptic hand cleaner or dishwashing detergent.
Dry: If cleaning is not practical, after the item is completely dry to touch, wait an additional 48 hours before contact or use in any other waterway.