& Microscopic Organisms
The lake may look sterile and devoid of life now that the Grass Carp have removed much of the aquatic plant growth, but actually the lake is teeming with small organisms. A good balance of these organisms is needed to provide food for larger organisms, such as birds and fish. Viewing lake water under a microscope can open up a whole new world of exploration. The Preservation Association of Devils Lake invites the public to attend our annual meeting (usually in June) to learn more.
What is the scum floating on the lake? It could be a blue-green algae bloom. Algae blooms can occur when there are nutrients in the water column and the temperature is warm. Winter storms and wave action from boats can stir up the lake bottom, releasing nutrients into the water column. If other conditions are right, an algae bloom can occur. Algae can be an indicator of limited water quality (pollution). Anabaena is a type of blue-green algae that can discolor the water and give off a putrid odor when the cells die off and decay. Devils Lake has seen an increase in the frequency of algae blooms from undesirable species, and a decrease in the diversity of desirable algae species. Algae in the lake can affect water clarity. Secchi disks are round, black and white disks that are lowered into the water from the surface. Clarity is gauged by how far down the disks go into the water before disappearing. Report algae blooms to the Devils Lake Water Improvement District (DLWID) at 541-994-5330.
Phytoplankton surveys from July 17, 1981 identified the following alga: Fragilaria crotonensis, Cryptomonas erosa, Anabaena sp., Kephyrion spirale, Ankistrodesmus falcatus, and four others.
Blue-green algal blooms - potential for toxins
North American Lake Management Society Blue-green algae page
Blue-green algae blooms on Devils Lake can occur when conditions are right. Most are non-toxic. However, you should avoid swimming in an area where there is an abundance of algae blooms. Some algae toxins can be harmful to pets, so keep your pets away from algae blooms.
The Oregon Department of Human Services has a download pdf brochure, download pdf flyer about algae, and a web page at www.oregon.gov/DHS/ph/envtox/maadvisories.shtml You can subscribe to receive blue-green algae advisories by email from the website. www.oregon.gov/DHS/ph/hab/advisories.shtml
• Washington State Department of Health
www.doh.wa.gov - Cyanobacteria were previously grouped with algae but are now classified as bacteria after analysis of cell structure and cell division. They differ from other bacteria in that they contain photosynthetic pigments similar to those found in algae and plants. Although they are predominantly photosynthetic (light-dependent) organisms, they are also capable of using organic compounds as a source of energy. Some cyanobacteria have a specialized structure called a heterocyst that can fix molecular nitrogen. The ability to fix nitrogen gives these species a competitive advantage over other algae. Many cyanobacteria have gas vacuoles that allow them to remain in suspension and migrate to surface waters where there is plenty of light for photosynthesis. On the surface, colonies may clump together and form a scum which can cause water quality problems in lakes.
Studies of algal blooms
Lost Creek Lake blue-green algae testing
quote from a news article after Diamond Lake was closed for 3 weeks
due to algal blooms. "The lake isn't meeting state water quality
standards. It isn't meeting the recreational and economic expectations
algae toxin types:
1. Endotoxins - skin rashes, irritation of the eyes, and gastroenteritis
2. Neurotoxins - damage nerves and can cause muscle tremors, especially in the muscles animals and people need to breath
3. Hepatotoxins - damage the liver
2008 Cyano-watch by the Devils Lake Water Improvement District (DLWID) - http://www.dlwid.org
• 9/24/08 - The RED Health Advisory posted August 14, 2008 remains in effect.