The North Carolina Department of Environmental Quality’s Division of Water Resources (DWR) has issued a public advisory regarding algal blooms in Lake Norman. The advisory, effective since June 16, warns against contact with green or blue water due to the presence of these blooms.
Algal blooms have been reported at various locations on the lake, particularly in the northeastern sections across Catawba, Iredell, Lincoln, and Mecklenburg counties. These blooms are subject to movement influenced by wind and wave actions.
Investigations by DWR at five sites revealed that the blooms are primarily composed of Dolichospermum, previously known as Anabaena. This type belongs to cyanobacteria or blue-green algae. Typically bright green in appearance, decaying blooms can turn milky blue and emit strong odors affecting larger areas.
Dolichospermum is capable of producing microcystins, toxins that pose health risks to humans and pets. Preliminary tests conducted on June 17 found no microcystins present; however, toxin production can be unpredictable. Continuous monitoring is underway with updates available on DWR’s Algal Bloom Dashboard.
The N.C. Department of Health and Human Services’ Division of Public Health advises avoiding large algae accumulations and preventing children and pets from swimming or ingesting water where algal blooms are present.
Precautionary measures include keeping children and pets away from discolored or scummy water, avoiding contact with large algae mats, not handling dead fish potentially affected by the bloom, thoroughly washing after exposure to a bloom, rinsing off pets exposed to such waters with clean water, seeking medical attention if illness occurs post-exposure for both humans and animals.
Algae naturally occur in all bodies of water but certain conditions like increased nutrients (nitrogen and phosphorus), high temperatures, sunlight exposure, and low water flow can accelerate growth leading to blooms.
Reports of algal blooms can be made through local DEQ offices or online submissions. For detailed information about ongoing events visit DWR’s Fish Kill & Algal Bloom Dashboard. Additional resources on health impacts are available on the DPH website.
