High levels of pollution in Lake Champlain, on the New York-Vermont border, are coming back to haunt local residents, fishermen and vacation-goers

While typically harmless to human health, blue-green algae can sometimes produce neurotoxins that can be dangerous if ingested.North Country Public Radio reports that there have been at least two outbreaks of blue-green algae -- which is a dangerous form of cyanobacteria -- so far this summer. 

The Plattsburgh Press-Republican notes that conditions are ripe for the algae this summer, and that recent outbreaks in the waters of Moriah and Port Henry could be a harbinger of things to come. A warm spring, hot summer, lower lake levels and plenty of phosphorous pollution are all contributing factors.

Not all blue-green algae contains toxins that can cause skin irritations, stomach aches and other health concerns in humans. But public health officials are warning swimmers to avoid problem areas. 

New York State also issued a warning against eating fish caught in areas with visible blooms of blue-green algae.