In 2005, the Washington State Legislature established funding for an algae control program and asked the Washington Department of Ecology (Ecology) to develop the program. Reducing nutrient input to lakes is the only long-term solution to prevent algae blooms. However the amount of money available for this program (about $250,000 per year) is not enough to fund comprehensive lake-wide and watershed-wide nutrient reduction projects. Instead the program focuses on providing local governments with the tools they need to manage algae problems. The program targets blue-green algae (also known as cyanobacteria) because these algae pose a health risk to humans, pets, and livestock.
The Grays Harbor County Division of Environmental Health is asking area residents to contact our office if potential harmful algae blooms are found in local freshwater bodies; please call (360) 249-4413. Upon discovery of potential harmful blooms field staff will collect samples and send them to Ecology for toxicity testing.
What is an Algae Bloom?
Many Washington lakes and even some rivers have problems with excessive growth of algae. Algae can be smelly and unsightly as well as being toxic to humans, pets, and livestock. Algae grow rapidly when sunlight, temperature, and nutrients are adequate. Within only a few days, a clear lake can become cloudy with algae. When an algal species reproduces rapidly and reaches high concentrations, it is called an algae bloom. The nutrients phosphorus and nitrogen are found in animal and human waste (sewage), in fertilizers, and even in rainwater. Too much phosphorus and nitrogen lead to nutrient rich water bodies. Nutrient-enrichment leads to algae blooms.
There are many types of algae. Most are harmless, some are considered nuisances, and others are important to lake productivity. Blue-green algae are actually bacteria called cyanobacteria. They can create problems when they form blooms. The blooms happen mostly in the summer or fall, but can occur anytime. Blue-green blooms may float to the surface and can be several inches thick near the shoreline. A blue-green algae bloom often looks like green paint floating on the water and is hard to pick up or hold.
Why is Ecology particularly concerned about blue-green algae?
Blue-green algae blooms pose a human health concern and have killed pets and livestock. Although most blue-green blooms are not toxic, some blue-green algae produce nervous system or liver toxins. Toxicity is hard to predict. A single species of algae can have toxic and non-toxic strains. A bloom that tests non-toxic one day can become toxic the next day.
People may become ill after swimming or water skiing in lakes with toxic blue-green algae. Human health effects may include stomach pains, vomiting, diarrhea, skin rashes, and nerve and liver damage. Pets and wildlife have died after exposure to toxic blue-green algae in Washington lakes. Blue-green blooms affect lake recreation creating economic losses.
