Algae Alert Lifted for North Fork of Shenandoah River as Sampling Suspends Until 2025

The Virginia Department of Health (VDH) has officially lifted its algae mat advisory for the North Fork of the Shenandoah River, marking the end of this year’s response actions. Since July, a warning has been in place from Deer Rapids Bridge to Strasburg, urging the public to avoid contact with water in the affected areas.

The Virginia Harmful Algal Bloom Task Force, which includes the VDH, the Virginia Department of Environmental Quality, and Old Dominion University’s Phytoplankton Lab, confirmed that sampling and response efforts end each October as cooler temperatures diminish algae growth. Although the recreational season has concluded, some algae mats remain visible, particularly in still or shallow water areas. Residents are advised to continue steering clear of discolored or greenish water, as it could still harbor harmful toxins.

Algae blooms often create scum or mats on the surface of the water. Some algae types produce toxins that, if ingested or touched, can cause skin irritation, respiratory issues, and gastrointestinal symptoms in humans and pets. While many types of algae are harmless, certain species pose a risk, especially during warmer months when blooms are most likely to thrive.

The task force will resume monitoring in May 2025, as warming weather can promote new algae growth, making the North Fork of the Shenandoah and other Virginia waterways safe for recreational activities once again.

For updates on harmful algae blooms and safety tips, visit www.SwimHealthyVA.com.