Toxic Cyanobacteria in Zion

 

Duration:

2 minutes, 52 seconds

The first in a series of three videos with information you need before recreating in still or moving water at Zion National Park.

 

Cyanobacteria can grow on surfaces like rocks, sticks, and sand. This cyanobacteria is attached to the side of the river. Note the yellow/brown color and vein-like texture.

NPS Photo

What are cyanobacteria?

Cyanobacteria, also known as “blue-green algae," are photosynthetic bacteria found in lakes, reservoirs, rivers, streams, and other bodies of water in many places throughout the world. In other waterbodies, cyanobacteria are found on the top of the water or dispersed throughout the water column.

In Zion, scientists have found cyanobacteria at the bottom of the Virgin River and its tributaries within the park. The kind of cyanobacteria attached to the bottom of the river is known as benthic cyanobacteria. Benthic cyanobacteria grows on rocks, plants, the sides of the river, and along the river's edge

Why are cyanobacteria harmful?

Cyanobacteria are naturally occurring, but they can harm humans or animals by producing toxins called cyanotoxins. Scientists have found anatoxin-a, microcystin, nodularin, and cylindrospermopsin in the park.

Young children and dogs are especially at risk of exposure. Do not let dogs drink from the river — they may consume toxins in the process. Children should be supervised to make sure they do not touch or consume algae.

According to the US Environmental Protection Agency, when people are exposed to cyanotoxins, they can experience a range of symptoms. These can include a mild skin rash, serious illness, or in rare circumstances, death.

Severe or acute illnesses caused by short-term exposure to cyanobacteria and cyanotoxins during recreational activities (like swimming) include hay fever-like symptoms, such as skin rashes, respiratory issues, as well as neurological or gastrointestinal distress. Drinking water contaminated with cyanotoxins (such as microcystin and cylindrospermopsin) could cause liver and kidney damage.

What do I do if I am exposed to cyanobacteria?

If you were exposed to cyanobacteria and feel ill, seek immediate medical attention and contact the Utah Poison Control Center at [phone]. If you are experiencing a medical emergency, call 911.

 

Exposure to cyanotoxins can cause a wide range of symptoms, some potentially life-threatening.

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Cyanobacteria Monitoring

Zion National Park monitors for the presence of toxic cyanobacteria and cyanotoxins throughout the park. We share information so you can make informed decisions about when and how to recreate. We work with the Utah Department of Environmental Quality to share current recreational advisory levels for still and flowing water. Recreational advisory levels include...

• Health Watch - Check First!
• Warning

Waterbody	Popular Areas Affected	Recreational Advisory Level
North Fork of the Virgin River	The Narrows Pine Creek Deep Creek Kolob Creek Orderville Canyon Emerald Pools All canyoneering routes with an active surface water connection to the North Forth of the Virgin River	Health Watch - Check First!
North Creek (Tributary of Virgin River)	Right Fork Left Fork (The Subway) Grapevine Spring All canyoneering routes with an active surface water connection to North Creek	Health Watch - Check First!
La Verkin Creek (Tributary of Virgin River	La Verkin Creek Timber Creek Hop Valley Creek All canyoneering routes with an active surface water connection to La Verkin Creek	Health Watch - Check First!

This table shows the current recreational advisory level for each monitored waterbody in the park. Do not touch or ingest algae mats. Do not drink from in steam water in the park; filter only directly from springs where algae mats are not present. During Warning advisory levels, visitors should avoid activities that could lead to ingestion of toxic mats. Young children and dogs are especially at risk of exposure

 

Where do cyanobacteria grow?

Cyanobacteria are photosynthetic and can grow anywhere sunlight reaches the water. Benthic cyanobacteria can grow at the bottom of still or flowing water and can also grow attached to plants, rocks, or at the edges of the river. Benthic cyanobacteria often form in mats, but not always.

Recognizing Cyanobacteria

Cyanobacteria grow in different colors and textures. In Zion, these colors include yellow, tan, green, brown, and black and can appear to be round, ribbed, or mucous-like.

 

Cyanobacteria attached to a rock near the water's surface. Note the black color and round shape.

NPS Photo

Cyanobacteria growing along the river's edge in Zion. Note the bubbly texture and brown color.

NPS Photo

Cyanobacteria growing along the river's bottom in Zion. Note the yellow color and vein appearance.

NPS Photo

This cyanobacteria is growing on a rock at the bottom of the river. Note the green color and feathery texture.

NPS Photo

 

Cyanobacteria is often seen growing on rocks at the bottom of rivers or streams.

NPS Photo

Cyanobacteria can grow on the roots, stems, or leaves of plants as well.

NPS Photo

 

How is Zion monitoring for cyanobacteria?

Park scientists monitor popular bodies of water for toxin-producing cyanobacteria and cyanotoxins. All data is shared with the Utah Department of Environmental Quality. Monthly monitoring data inform the recreational advisory level. Recreational advisory levels can be found on the park's website, at all visitor contract stations, and on signs posted at major trailheads.

Monitoring Techniques

Scientists perform visual inspections of selected sites in three major tributaries of the Virgin River in Zion National Park to determine if cyanobacteria are visually present. Zion National Park issues advisories primarily based off percent coverage of toxin-producing cyanobacteria, in accordance with the Utah Benthic Cyanobacteria Advisory Guidance (version 1.5).

 

Duration:

1 minute, 51 seconds

Information about the cyanobacteria in the flowing and still water of Zion National Park and the types of cyanotoxins they produce that can be potentially harmful.

 

Frequently asked questions

What do I do if I was exposed to toxic cyanobacteria?

Can I filter or boil the water to make it safe for drinking? 

What symptoms will I experience if I am exposed to cyanobacteria? What about pets?

Just how dangerous is cyanobacteria?

What is causing the growth of cyanobacteria in Zion?

If I have an open wound is there a health risk hiking in the water?