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VDH Expands North Fork River Recreation Advisory to Include a 52.5 Mile Segment from Chapman’s Landing to Front Royal.

The Virginia Department of Health has conducted additional testing on algal mats and water samples above and below the advisory area already in place. These tests identified cyanobacteria and cyanotoxins at some, but not all of the sites tested in the extended advisory area. All evaluated sites contained cyanobacteria capable of producing toxins, with the exceptions of Lupton Road at Seven Bends State Park, and the low-head dam near Sandy Hook Road in Strasburg.

People and Pets Should Avoid Contact and Accidental Ingestion of Cyanobacteria Mats Anywhere in the River

Toxins found in these mats of algae can cause skin irritation and gastrointestinal problems for humans. If ingested, toxins from cyanobacteria can be lethal to pets and other animals.

For more detailed images and information from the CDC regarding cyanobacteria:

Click here for the CDC’s Cyanobacteria FAQ Page

Click here for Information for Pet and Livestock Owners

Photo of algae from Lower River Road submitted to

If you see an algal mat like the one above, do not enter the river and keep your pets away.  Not all mats are toxic, but when in doubt, stay out!

You Can Help!

Thank you to everyone who submitted photos of algae from around the watershed to algae watch. These photos were shared with the VDH, DEQ, and Shenandoah Riverkeeper, and helped everyone get a clearer picture of the scope of the issue in the North Fork.

When you find a suspected algal bloom in the North Fork, take a photo and send it to us at

Please include the location of your photo and any other observations you have.
(e.g., wildlife, fish, odor, litter, river flow, etc.)

We will continue to share a digest of these collected reports with VDH, DEQ, and the Shenandoah Riverkeeper to aid in their efforts to test for harmful algae, keep the public informed, and combat the source of algal blooms.  Friends will not share your name or any personal information in connection with any photos you submit, unless you specify that you would like to be credited.

Click here to see our AlgaeWatch map with photos collected so far.

If you are interested in documenting local sites weekly, to track the progression of blooms over the next 6 to 8 weeks, please let us know in an email to  

We will keep you posted as more information is released.