STARRY STONEWORT UPDATE AS OF MARCH 24, 2024

The starry stonewort situation on Middle Cullen Lake is changing, and seemingly in a good way.

Unlike last year, the Minnesota Department of Natural Resources will allow the Cullen Lakes Association to chemically treat the infestation that exists near the boat-launching site at the northeast end of the lake.

During a management meeting with the DNR this spring, board members learned:

  • The DNR will permit the treatment of starry stonewort in 2025 as proposed by Tigris, the water management firm the CLA, following a vetting process, deemed best for the job. Tigris has an office in St. Cloud. The association has worked extensively and successfully in the past with the St. Cloud Tigris agent when he worked for a different firm.
  • The first treatment will likely occur towards the end of April. A second and perhaps third treatment will occur later in the year.
  • The chemical application (copper sulfate) will likely cost about $3,000 per treatment. This dollar amount is calculated, in part, by the size of the infestation (nearly an acre) and water depth. Currently, this unwanted form of algae is dormant. The plan is to hit it hard when it starts to green-up and grow robustly. The DNR deemed that chemical treatment is superior to trying to remove it by hand, which is unpractical due to the infestation’s size and density.
  • The CLA has applied for DNR grant funds to offset the cost of this invasive species control. The CLA has been told it can expect some funding though it has not heard a precise dollar amount.

 

As you may recall, starry stonewort was discovered in Middle Cullen in May of 2024. If it exists in Upper and Lower Cullen it has not yet been found.

An invader from afar, starry stonewort was first discovered in North America in 1978 on the east coast. It has been spreading ever since. It has never been eliminated from a lake once an infestation has been established. Today, starry stonewort exists in about 30 Minnesota lakes.

Though the DNR agrees that a chemical approach is the best option for controlling and containing the Middle Cullen infestation, the agency also cautions about unrealistic expectations. Chemicals are not 100 percent effective because the algae does not have a vascular system to spread the poison beyond the immediate point of contact. Moreover, poison sometimes sparks even more aggressive growth as the algae senses it is under attack and fights harder to survive.