The water is as green as a sheet of nori in Edenton Bay, as potentially toxic algae is blooming in the waterway near the Albemarle Sound in Eastern North Carolina, according to state environmental scientists.
The state Division of Water Resources received a report of green water on July 19 from a Chowan County environmental group. DWR staff collected samples and found dense concentrations of blue-green algae called Dolichospermum planctonicum, which can produce cyanotoxins.
Cyanotoxins can make people sick — affecting the gastrointestinal tract, liver, nervous system and skin — and even kill animals, including livestock, that ingest water tainted with it. There have been no reports of illnesses or deaths attributable to this algae bloom, but the state health department advises people to avoid the affected water, and to keep their pets away from it.
The Chowan River, which flows into bay and the sound, is not a drinking water source. However, farmers do use it for irrigation. The area is also popular among boaters, fishermen and water-skiers.
This is the third reported algae bloom in North Carolina this summer. On June 23, the state Department of Environmental Quality investigated a potential bloom in Lake Fontana, in Graham and Swain counties. And from May 31 to June 8, Greenfield Lake in Wilmington also had a bloom.
Blue-green algae blooms are common in the summer, although not all algae — some is actually a form of bacteria — is toxic. Sunlight and intense heat combine with nitrogen, such as that from the runoff of fertilizer used on fields and lawns, to stoke its growth, says Steve Gabal of the Chowan County Cooperative Extension. The algae form dense mats, which block sunlight and consume oxygen in the water, and can result in fish kills.
Algae also bloomed in the Albemarle Sound last summer.
Storms or cooler weather can clear the water of much of the algae, Gabal says.
Algae blooms have long plagued Jordan Lake in central North Carolina, a drinking water source for more than 300,000 people in the Triangle. But instead of implementing stiffer restrictions on development in that watershed, state lawmakers, over the objections of environmental advocates, voted twice to fund a deployment of solar bees to stir parts of the lake. After two years, the water quality had not improved, and this spring, DEQ ended the $1.5 million project.
The blooms in the Edenton Bay are not as severe as the algae in south Florida. Described as “guacamole thick” the algae is proliferating off the Atlantic Coast, prompting Gov. Rick Scott to declare a state of emergency in two counties.