Lake algae advisory continues

For a 14th consecutive week, a blue-green algae advisory for Marion County Lake was extended Friday.

The lake joined 18 other bodies of water in Kansas that will be under watches or warnings for the next week.

Eight of them, like the county lake, are under less-serious watches, as determined by Kansas Department of Health and Environment.

A watch does not indicate that toxic blue-green algae are present, only that a harmful bloom might occur. When a watch or warning is declared, KDHE 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 blooms. 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 clear water. Fish caught 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 ones include rash, vomiting, diarrhea, fever, sore throat, and headache. In rare cases, algae may release a potent neurotoxin.

Residents and officials have suggested that algae advisories at 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 on the lake now is being discouraged 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 is development of land near the concrete slab bridge at the northeast end of the lake.

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

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

Projects to restore wetlands along the edges of Marion Reservoir have been credited with reducing algae advisories there.

The reservoir has not faced an algae advisory since July 19.