Public Advised to Avoid Contact with Algal Mats in sections of the North Fork of the Shenandoah River near Town of Strasburg, VA

An Algal Mat Alert has been issued for the North Fork Shenandoah River for the Town of Strasburg. The alert area begins above the town at approximately Route 644 (Deep Hollow Lane), to include the Deer Rapids Road Bridge, to below the town at approximately Route 611 (Long Meadow Road), for a total of approximately 11.5 miles. Potentially toxic algae mats could be widespread or patchy in areas within this vicinity. Recreational use may continue providing those using the waterway take caution to avoid contact with the algae mats. If mats appear unavoidable in an area, the public should discontinue recreational activities there.

Algal Mat Alert signs have been posted near the boat ramp at Deer Rapids and at public access points along the North Fork Shenandoah River in Strasburg. The area of the river where algal mats have been investigated can be seen on the interactive Harmful Algal Bloom Map.

While this alert applies to this particular area, everyone is reminded to avoid areas in any natural waterway that have algal mats or discolored, scummy water. People should also avoid allowing their pets to swim in areas where mat material is observed. Contact with these mats may cause skin rash and gastrointestinal illnesses, such as upset stomach, nausea, vomiting and diarrhea. If mats are producing toxins, consumption of mats could be fatal to dogs and other animals when ingested. Sadly, animal deaths may occur suddenly following exposure. Humans should never consume water or material from a natural waterbody because this water is not treated water and is not suitable for consumption.

Although cyanotoxins were either below or just above detection in water samples tested from these locations, it is important to remember that toxin concentrations within the mats may be much more highly concentrated than those that may be in the water column. Avoiding contact with mats should avoid the release of toxins to the water, if mats are producing them.

VDH has observed no evidence of impacts to drinking water at this time. The Office of Drinking Water is working with drinking water utilities to protect drinking water sources.

The North Fork of the Shenandoah River is a popular local recreation area for boating, swimming and fishing. Please look for Algal Mat Alert signs posted along the river shoreline at public access points and observe the advisory precautions. Recreational uses may continue provided proper caution to avoid mats is observed. It is best to ensure pets, livestock and horses do not have access to this section of the river when mats are present.

Algae blooms can occur when warm water and nutrients combine to make conditions favorable for algae growth. Most algae species are harmless, however, some species may produce irritating compounds or toxins. Avoid discolored water, scums or mat material that are green or bluish-green because they are more likely to contain toxins.

To prevent illness, people should:

• Avoid contact with mats which may be present in North Fork Shenandoah River above and below the Town of Strasburg.
• If mats are unavoidable, do not attempt to recreate in the waterbody.
• WHEN IN DOUBT, KEEP PEOPLE AND PETS OUT! Use your best judgment before recreating in natural waterbodies.
• Do not allow children or pets to drink from natural bodies of water or consume material in the water or along the shoreline.
• Keep small children, pets, and livestock out of the areas experiencing an Algal Mat Alert. They do not understand the risks associated with mats and may drink river water or consume mats which could cause illness.
• If you or your animals experience symptoms after swimming in or near the area under an Algal Mat Alert, seek medical/veterinarian care. You may also contact your local poison control center.
• Additional resources for pet owners and veterinarians are available from the CDC at www.cdc.gov/habs
• To ensure fish filets are safe to eat, properly clean fish by removing skin, discarding all internal organs, and cooking fish to the proper temperature.
• To view the Algal Mat Alert area, view the HAB Map online or the Algal Mat Status Report for the North Fork Shenandoah River 8.5.22.
• To report an algae bloom or fish kill, use the online report form.
• If you suspect you or your animal experienced health-related effects following exposure to a bloom, contact the Virginia Harmful Algal Bloom Hotline at 1-888-238-6154. Please do not call this number for updates on sampling or status reports.

The Virginia Harmful Algal Bloom Task Force, which includes the Virginia Department of Health, Virginia Department of Environmental Quality, and the Old Dominion University Phytoplankton Analysis Lab, will continue to monitor mats in the river. In general, Algal Mat Alerts may be lifted following two consecutive observations where mats are not widespread and unavoidable and preferably, as resources allow, when water column cell counts and toxin concentrations are below safe swimming thresholds. An Algal Mat Alert may also be lifted or maintained at the discretion of the health department. For example, after one test an advisory may be lifted if results are within safe levels for swimming if other information indicates exposure or human health risk is low.

For more information about harmful algae blooms, Algal Mat Advisories and Recreational Water Advisories visit www.SwimHealthyVA.com.