Algae advisory extended for 12th week

Marion County Lake’s blue-green algae advisory was extended Friday for a 12th consecutive week. The advisory does not extend to Marion Reservoir.

The advisory is the lowest level of alert — a watch, not a warning or hazard status. A total of nine bodies of water in the state were placed under more-serious warnings Friday, while 10 others joined the county lake on the less-serious watch list.

A watch indicates that a harmful bloom may be present. Kansas Department of Health and Environment requires that signs be posted at all public access points.

Visitors are warned that water may be unsafe for humans and animals. Swimming, wading, skiing, and jet skiing are discouraged near visible blooms, if any. Boating and fishing are safe, but inhalation of spray might affect some people

Direct contact with water should be avoided, and visitors should wash with clean water. Fish caught from the lake are considered safe to eat as long as they are washed in clear water and only the filet portion is eaten.

An algae bloom could look like foam, scum, or paint floating on water and be colored blue, bright green, brown, or red. Blooms can develop rapidly.

Symptoms of illness vary with the species of algae. Common symptoms include rash, vomiting, diarrhea, fever, sore throat, and headache. In rare cases, algae may be a potent neurotoxin.

Residents and officials have suggested that algae advisories on the county lake may be attributable to wakeboarding — a type of skiing that features boats designed to create wakes that may disturb algae on the lake bottom.

Wakeboarding often is outlawed on lakes as small as Marion County Lake not only because of the disturbance of the lake bottom but also because it can damage docks.

Another factor that may contribute to algae advisories at the county lake is the development of land near the concrete slab bridge at the northeast end of the lake.

That area formerly was wetlands covered in cattails, which are known to filter out nutrients that contribute to algae growth.

Use of agricultural and residential fertilizers in the watershed also contribute to algae growth.

Officials have stated that projects to restore wetlands along the edges of the reservoir have reduced algae advisories there.