The North Carolina Department of Environmental Quality’s Division of Water Resources (DWR) has issued an advisory for the public to avoid contact with green or blue water in the Chowan River and its tributaries between Occano and Arrowhead Beach due to persistent algal blooms observed since October 6.
The blooms have been found in Bertie and Chowan counties, specifically at the confluence of the Chowan River and Salmon Creek near Occano, near Whites Beach, and on Dillard Creek (Indian Creek) at the Arrowhead Beach boat launch. The DWR noted that the location of algal blooms can shift due to wind and wave action.
Analysis of water samples revealed that the blooms are dominated by Dolichospermum (also known as Anabaena) and Microcystis, both types of cyanobacteria or blue-green algae. According to the DWR, “Cyanobacterial blooms usually appear bright green, but when a bloom starts to decay, the color can change to a milky blue. Decaying algae may produce a strong, foul odor that can impact a large area.”
These algae species are capable of producing microcystin, a toxin that poses health risks to humans and animals. Testing detected microcystin concentrations of 2,600 parts per billion at the Chowan River and Salmon Creek confluence near Occano, 35 parts per billion near Whites Beach, and 89 parts per billion on Indian Creek near its confluence with the Chowan River. All these levels exceed public health advisory thresholds.
Results from these tests have been published on DWR’s Algal Bloom Dashboard. The North Carolina Department of Health and Human Services Division of Public Health (DPH) has reiterated its guidance to avoid contact with large accumulations of algae and to keep children and pets from swimming in or ingesting water from affected areas.
DPH recommends several safety measures: “Keep children and pets away from water that appears bright green, blue, discolored, or scummy. Do not handle or touch large mats of algae. Avoid handling, cooking, or eating dead fish that may be present. If you come into contact with an algal bloom, wash thoroughly. Use clean water to rinse off pets that may have come into contact with an algal bloom. If your child appears ill after being in waters containing an algal bloom, seek medical care immediately. If your pet appears to stumble, stagger, or collapse after being in a pond, lake, or river, seek veterinary care immediately.”
Residents are encouraged to report algal blooms to their nearest DEQ regional office or online. Reported events can be viewed on DWR’s Fish Kill & Algal Bloom Dashboard. Additional information about algal blooms is available on the DWR website, and health-related details can be found on the N.C. DHHS website.
The DPH also reminds people to take precautions against other microorganisms or pollutants in waterbodies that can cause recreational water illnesses. More details are available at https://epi.dph.ncdhhs.gov/cd/water/prevent.html.
