ANNANDALE -- Another Minnesota lake has become infested with starry stonewart.

The invasive aquatic species has been discovered in Wright County's Pleasant Lake near Annandale. It is the 13th Minnesota lake where starry stonewart has been found.

The Minnesota Department of Natural Resources says an invasive species specialist was investigating a report of zebra mussels in the lake when the starry stonewart was found. No zebra mussels were found, however.

The DNR says the starry stonewart was 12-15 inches tall, covering about four-square-feet and found in 8-10 feet of water near the public landing on the north end of the lake.

The public landing is now closed while a treatment plan is being developed.

Starry stonewart can form dense mats which can interfere with the lake's use and competes with native plants. It has never been eradicated from any U.S. lake.