The blue-green threat

CHARLOTTE, N.C. Golden algae is the killer of fish. Since the first documented die-off in 1985 on the Pecos River in Texas, it has killed millions of fish.

CHARLOTTE, N.C. — Golden algae is the killer of fish. Since the first documented die-off in 1985 on the Pecos River in Texas, it has killed millions of fish.

This algae poses no threat to human health, but some species of cyanobacteria, the blue-green algae, do. In severe situations, blooms spread throughout the water or appear as floating scum in various shades of blue and green or even brown and red.

They can harm pets, livestock and wildlife. Danger occurs when the blooms produce toxins, including microcystin. Some of these cyanotoxins are among the most potent known, according to Dr. Ken Hudnell. Although the blooms themselves can cause foul odors, the toxins generally can’t be seen, smelled or tasted. But they can harm the nervous system and the liver, and they can persist in the water even after the blooms are gone.

Best advice is to avoid contact with waters that have algal blooms, especially when the water is discolored. If you become ill after swimming, seek medical attention right away. Also know the signs of algal bloom poisoning, including dizziness, headache, abdominal pain, numbness of lips, diarrhea, vomiting, and tingling in fingers and toes.