Once More Toxic Algae Spotted in Virginia

The Virginia Department of Health has issued a “Harmful Algae Bloom Advisory” where the Public is Advised to Avoid Water Contact for North Anna Upper and Middle Branches of Lake Anna, and the Upper Pamunkey Branch.  In addition, a Harmful Algae Bloom Advisory has been issued for the North Fork of the Shenandoah River.

Toxic blue green algae has been found in Lake Anna in Orange, Louisa and Spotsylvania counties in the North Anna Upper and Middle Branches in addition to the Upper Pamunkey Branch as well as the North Fork of the Shenandoah River in Shenandoah County. The VDH announced that these areas are “experiencing a harmful algal bloom (HAB) and advised the public to avoid contact with the lake in these areas until algae concentrations return to acceptable levels. These warnings seem to be more frequent in recent years.

Algae blooms form in summers when higher temperatures reduce the oxygen holding capacity of the water, the air is still and especially in years of heavy rains that carry excess nutrient pollution from cities, suburban lawns and farms. The excess nutrient pollution combined with mild weather encourages the explosive growth of algae fed by excessive nutrient pollution.

Not all algal blooms are toxic or hazardous. Only certain species of blue-green algae form the toxin, for reasons that aren't fully understood. Toxic bacteria were not a problem until the 21st century, though algae blooms have been a problem on Lake Erie, the Gulf of Mexico, the Chesapeake Bay and other areas for over half a century. Only algae that contains microcystine or cyanobacteria, a toxin produced by microcystis, a type of blue-green algae that spreads in the summer algae bloom are hazardous.

In the 21st century toxic or hazardous algal blooms have become a global concern in lakes, rivers and oceans. They occur when algae grow out of control under favorable environmental conditions. Hazardous algal blooms, the ones that contain microcystis algae produce microcystine or cyanobacteria toxins, that can lead to the poisoning of fish, shellfish, birds, livestock, pets and others that can lead to human health impact from eating fish or shellfish exposed to toxins as well as drinking water contaminated by toxins.

Some of the most commonly occurring genera of algae are Microcystis, Dolichospermum (previously Anabaena), and Planktothrix. Microcystis is the most common bloom-forming genus and is almost always toxic. According to the U.S. EPA climate change along with nutrient pollution, might be additive factors that combine to cause harmful algal blooms to occur more frequently and in more waterbodies and to be more intense. According to the EPA:

• Harmful algae usually bloom during the warm summer season or when water temperatures are warmer than usual. Warmer waters due to climate change might favor harmful algae growth.
• Climate change might affect rainfall patterns, leading to alternating periods of drought and intense storms. This can cause more nutrient runoff into waterbodies, feeding more algal blooms.
• Algae need carbon dioxide to survive. Higher levels of carbon dioxide in the air and water can lead to rapid growth of algae, especially toxic blue-green algae that can float to the surface of the water.

 Virginia Tech Extension and the Virginia Department of Health advise:

• Avoid contact with any area of a lake or pond where water is green or an advisory sign is posted. WHEN IN DOUBT, STAY OUT!
• Waters that are discolored or have foam, scums or mats that are green or blueish-green should be avoided because they likely contain toxins.  Harmful algae can also be brown or red, and can resemble paint floating on the water.  Toxic algae can stink, smelling nauseating to people, but can be attractive to animals like dogs.
• Do not allow children or pets to drink from natural bodies of water.
• Keep children and pets out of the areas experiencing a harmful algae bloom and quickly wash them off with plenty of fresh, clean water after coming into contact with algae scum or bloom water.
•  If you, your kids or your animals experience symptoms after swimming in or near an algal bloom, seek immediate medical/veterinarian care.

Symptoms: Human contact with HABs can cause rashes, stomach upset, diarrhea and vomiting.  Dogs can show symptoms including staggering, drooling, breathing difficulty, convulsions or seizures.

To ensure fish fillets are safe to eat, properly clean fish by removing skin and discarding all internal organs, and cooking fish to the proper temperature.

For keep abreast of the areas to avoid Virginia Department of Health maintains an interactive map at www.SwimHealthyVA.com.