Freshwater Red Tides

“Red tide” is an ominous-sounding name for the phenomenon in which certain algal species bloom in such high concentrations that a reddish-brown discoloration of the water results. Red tide events fall into the scientific category of “harmful algal blooms” (HABs); red tides and other HABs can result in the presence of various toxins in the water, which may be hazardous for humans, pets, livestock, and/or fish, depending on the causative species. While red tides are typically associated with coastal areas, the freshwater blue-green algae strain can have blooms that appear reddish (they may also be neon green or bright blue-green), resulting in a freshwater “red tide” event. Blue-green algae is a cyanobacteria that can produce toxins that irritate the skin and/or respiratory system in humans. Blue-green algae bloom events, which are most likely to occur during the warmest months of the year, have been reported with growing frequency in North Carolina in recent years. As a general precaution, avoid wading or swimming in any water that shows signs of an algal bloom (discoloration, dense mats of algae, foam or scum on the water surface, and/or a noxious odor can all be indicators) and never drink untreated lake or pond water when an algal bloom is suspected. If you do come into direct contact with an algal bloom, rinse off the area of skin contact with clean water as quickly as possible. Algal blooms can be treated and controlled; if you suspect a bloom in your lake or pond, contact us!