In Oklahoma and Texas lakes, rivers, and streams we have two kinds of Harmful Algae Blooms (HABs) that affect us the most, blue-green algae and golden algae. When algae reproduces rapidly, a bloom occurs, and these blooms become more abundant than is typically natural.
Blue-green algae is cyanobacteria, which produces cyanotoxins that are harmful to humans and animals. The most frequently reported type of bloom-forming cyanobacteria is microcystis. Golden algae is prymnesium partum and is harmful to gill-breathing aquatic species like fish and mussels.
Nutrient Pollution Causes Algae Blooms
Nutrients like nitrogen and phosphorus are vital to plant growth and natural elements of underwater ecosystems. When these nutrients run off urban and rural ground surfaces and flow into a river, lake, pond, or reservoir in excess, they create a phenomenon called nutrient pollution. The nutrients become a fertilizer for algae to bloom and become toxic.
Excess nutrients enter bodies of water through agricultural runoff from animal manure and chemical fertilizers that are washed into waterways from farms by rain and leaked waste from animal feedlots. Storm water runoff from urban and suburban areas and discharges from wastewater treatment facilities also contribute to nutrient pollution.
Blue-Green Algae
The most frequent and severe blue-green HABs, or CyanoHABs are caused by cyanobacteria, the only freshwater algae with that produces toxins which are detrimental to human health. Modern advances in scientific understanding of cyanobacteria have left many unanswered questions about this toxin.
Scientists do not understand environmental triggers for toxicity, and predicting the timing, duration, and toxicity of CyanoHABs at this time. CyanoHABs threaten human health, aquatic ecosystem health, and cause economic instability to waterways that depend on a recreational economy.
Blue-green algae can quickly grow out of control. When algae does get out of control, it is called a “bloom”. This occurs in warm, slow-moving water over 75 degrees that is full of nutrients which fertilize the algae. Blooms occur in fresh water, salt water, and brackish water, which is a mixture of fresh and salt water, around the world naturally and from human interference.
Harmful Effects of Blue-Green Algae to Humans
Drinking water with cyanobacteria produces several types of toxins that can affect nervous and respiratory systems, and other cyanobacteria toxins affect the liver. Symptoms appear shortly after exposure to the toxins.
Symptoms from drinking water with cyanobacterial toxins include headaches, nausea, fever, sore throat, dizziness, stomach cramps, diarrhea, abdominal pain, vomiting, muscle aches, mouth ulcers and blistering of the lips. Contact with water contaminated with cyanobacteria include skin rashes and irritation of the ears and eyes.
If you believe that you have been exposed to cyanobacteria toxins, immediately rinse off with clean water and check in with your health care provider.
Pets and Livestock Exposed to Cyanobacteria
Animals become exposed to cyanobacteria toxins by drinking, wading, or playing in contaminated water. Symptoms of exposure to animals also appear quickly after exposure.
Symptoms of blue-green algae toxicity in animals include diarrhea, disorientation, excessive drooling, jaundice, liver failure, panting, respiratory failure, seizures, and vomiting. Cyanobacteria toxin poison can cause death. Blue-green algae cells can adhere to fur. Animals can ingest the toxins from their fur when they clean themselves.
If you believe your animals have been exposed to cyanobacteria toxins, immediately rinse your pets and animals off with clean water and call your veterinarian.
How to Spot Blue-Green Algae
Blue-green algae blooms might look like foam, scum, or mats, on the surface of the water. Water containing blue-green algae blooms often looks like pea-green paint and appears as a film or slime on the water’s surface. This film, or slime, can build up on the shoreline giving the appearance of foam in windy conditions.
How to Prevent Illness from Blue-Green Algae Blooms
- Call the governing authority who manages and operates the lake or river you plan on visiting. These authorities regularly test the water to make sure the water is safe.
- Boiling water does not remove cyanobacterial toxins from the water and can even increase the concentration of toxins
- Never drink untreated water from lakes, ponds, or wetlands.
- Never mix infant formula with water that you suspect contains cyanobacteria.
- Follow swimming advisories related to cyanobacteria blooms or toxins.
- Never wade, swim, or bathe in water with visible blooms.
- Never cook, wash dishes, or do laundry in water contaminated with blooms.
- Wear rubber gloves when washing a pet exposed to cyanobacteria.
- Use fresh water to wash hands well after cleaning your pet.
Golden Algae Blooms
Golden algae is not harmful to humans, but can have devastating effects on aquatic species populations and the economy related to the lake or river which depends on fishing. It is only harmful when it is in bloom.
Golden algae, prymnesium parvum, is a microscopic, single-celled species of algae. When a toxic golden algae bloom lasts one month or less, a partial fish kill occurs, and the water body recovers more quickly. When a bloom lasts much longer, and a large part of the water body is contaminated, all populations of fish in that water body can die at a high rate.
Water quality, cooler water temperatures, other nutrients in the water, low rain levels, and low amounts of healthy green algae seem to work together to create favorable conditions for a golden algal bloom. Golden algae has yellow-green or golden-brown pigments. Water typically appears golden when it blooms.
Golden algae first appeared in North America in Texas in 1985. Biologists are uncertain if golden algae is native and never identified, or if it was an exotic algae species accidentally introduced into North America. Research is ongoing to establish early detection of golden algae, but biologists have not found a solution.
When golden algae blooms and produces a fish kill, there are much less fish to reproduce, and this reduces the amount of fish to catch in a body of water affected by a golden algae bloom. Sunfish, threadfin shad, and most species of minnows grow fast and produce large numbers of eggs and recover rapidly from golden algae blooms.
How Golden Algae Blooms Affect Fish and Mussels
Harmful golden algal blooms produce toxins that affect gill-breathing organisms and can cause massive fish and mussel kills. Golden algae toxins attack fish and mussel cells which allow excess water and waterborne chemicals inside them.
Golden algae toxins attack the outside layer of cells in gill-breathing aquatic species, the next layer of cells are affected, and this process continues until their gills become so badly damaged that they cannot function properly. Blood vessels in the gills leak into the water. Toxins and chemicals then get into their circulatory systems.
This process destroys their internal organs. The fish and mussels cannot receive oxygen. They move up to the top of the water or lay on the bottom of shallow waters and at edges of the shorelines. Catfish and bass are predators and need the minnows and shad to reach a reproductive age which takes several years. A body of water contaminated with a long-lasting golden algae bloom can take several years to recover.
Golden algae blooms seem to have no effect on humans, animals, or birds. Biologists have observed cattle, predators, scavengers, and birds drinking water and eating dead fish during a golden algae bloom with no apparent effects. They believe this is because the golden algae toxins break down in the acidic environment in the digestive process through their stomachs. People should never eat dead or dying fish during a golden algae bloom.
Always call the governing authorities who manage and operate a body of water you plan to visit to find out if there is an algae bloom. Usually, local media will broadcast an outbreak of an algae bloom.
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