Columbia River Recreation Becoming More Dangerous This Fall

❗ The Columbia River is in peak season for cyanobacteria blooms.

❗ These blooms can be deadly to pets and livestock, and quite harmful to people.

❗ Caution is urged when along the river during fall.

The weather is finally cooling off here in Tri-Cities, but the outdoors still calls us. For many of us, that means it's time to park along the Columbia River and take a long walk along the great trails and walkways that put us within arm's reach of nature. Others will be boating, fishing, swimming, or letting their dogs off-leash to splash into the river.

Many areas of the Columbia River may not be safe for recreation

If you're new to the area, you may not realize that the Columbia River, particularly around the Tri-Cities, faces a serious problem: toxic algae bloom. The problem, however, is new to long-term residents of the area, too. It wasn't until 2021 that this algae bloom was found in the Columbia River. Many dogs died that year as innocent pet owners let their pooches play in the river, not knowing the danger the dogs were in.

Unsafe areas of the Columbia River near Tri-Cities as of October 7, 2024

• Scooteney Reservoir is unsafe for recreation
• Charbonneau Park and Hood Park have elevated levels unsafe for pets
• South Moses Lake is unsafe for recreation

Howard Amon's swim dock has also been removed due to safety concerns for algae bloom, but it is still deemed safe to swim at this time.

What is toxic algae bloom?

Also called algal blooms, these waves of murk in the water are cyanobacteria - a bacterial organism that behaves similarly to plants. These bacteria can develop in certain conditions into a "bloom," a large, visible mass, which may either float along the surface of the water (planktonic), or cling to the structures at the bottom of the water (benthic). The image below shows an example of both, although they can be different in appearance and color. Most blooms found in the Columbia River are benthic.

The bloom is dangerous because the bacteria in it produce "toxins that affect water quality, ecosystem stability, surface drinking water supplies and public health," per Benton-Franklin Health District. Contact with the algae can lead to sickness that may be mild to life-threatening, depending on the type of algae, the type of exposure, and the length of exposure.

What types of things can expose me to the bacteria?

Per the CDC, exposure can occur through drinking water, inhaling water droplets, or ingesting contaminated food.

That means that if the Columbia River looks murky, you should leave. Swimming, drinking, boating, and fishing will all put you at risk. Just being close to the water might lead to an accidental inhalation of a water droplet from river spray. The same goes for pets and livestock.

Note: it is not yet clear whether eating freshwater fish caught in a bloom can be harmful; however it is officially discouraged. The Oregon Health Authority offers advice to fishermen who decide to eat the fish against this precaution.

What are the symptoms of illness caused by toxic algae bloom?

The Centers for Disease Control lists these common symptoms for humans affected by the bacteria:

• Stomach pain
• Rash
• Headache
• Coughing
• Watery eyes
• Nose irritation
• Sore throat

More severe symptoms include:

• Liver damage
• Seizure
• Irregular heartbeat

Symptoms in pets and animals can include vomiting, loss of energy, stumbling or falling, and seizures.

If these symptoms are present, a doctor or veterinarian should be seen immediately.

Benton-Franklin Health District began its annual monitoring of the river systems this year on May 20, and tests regularly. They will update the public as data becomes available. Warning signs will be posted where algal blooms are found and it is unsafe.

Stay safe this autumn, and remember the easy saying:

If in doubt, stay out!