ENFIELD — The New Hampshire Department of Environmental Services issued a cyanobacteria watch for Mascoma Lake last Friday, according to an Enfield news release. The watch is likely to remain in effect until Friday.

DES confirmed the presence of cyanobacteria near the Enfield boat launch last week. There also was a second bloom on the south end of the lake deemed “likely cyanobacteria” based on photos, but a sample of the algae was not taken, according to DES’ Healthy Swimming Map.

The boat launch bloom dissipated by 5 p.m. last Thursday, but the lake is still under a cyanobacteria watch.

“Be on the lookout,” Martha Jane Rich, president of the Mascoma Lake Association, wrote in a post to the EnfieldListserv, which the town shared to its email list on Monday. “Look closely at the water you are about to enter. Watch for shifting bloom conditions.”

This year, DES has changed its cyanobacteria protocol. In past years, the agency recommended staying out of the lake for a week after cyanobacteria was confirmed.

Now, a “watch” means that people should “be aware” that there has recently been increased amounts of cyanobacteria.

If there does appear to be cyanobacteria, green algae or the water looks unusual, people and animals should avoid contact with the water and report the sighting to DES online at https://survey123.arcgis.com/share/151c9fc3c8214c2e93325f77e0f1d578.

DES maintains a map of all active cyanobacteria watches and warnings in New Hampshire online at des.nh.gov/water/healthy-swimming/healthy-swimming-mapper. In Vermont, cyanobacteria blooms are tracked online at healthvermont.gov/environment/tracking/cyanobacteria-blue-green-algae-tracker.