STARRY STONEWORT UPDATE AS OF SEPT. 20, 2024
As you likely know, starry stonewort was discovered in Middle Cullen Lake in mid-May. This is highly disappointing because this unwanted form of algae has never been successfully eradicated in a United States lake or river.
Since May, members of the Cullen Lakes Association Aquatic Invasive Species Committee have been in on-going conversations with Minnesota Department of Natural Resources experts on how best to address this problem. DNR AIS specialist Camden Droppo attended the board’s Sept. 14 meeting to give an update on the situation. Takeaways from that meeting include:
· The total size of the infestation, located near the boat landing on the north end of the lake, remains about one-half acre in size. Thankfully, the algae has not grown to a height at which it can be hit by motorboat propellers, thereby increasing the likelihood that it will spread via fragmentation. The tallest growth is still about 10 feet below the surface.
· The DNR will not permit our association to take any containment or eradication action. The DNR’s position is that the best course of action, for now, is to monitor the infestation and take a “wait and see” approach. This approach, the DNR says, is supported by research conducted by the University of Minnesota Aquatic Invasive Species Research Center and certain other noted national scientists who study starry stonewort.
· Based on the observations of DNR divers and other on-site data, the DNR has deemed that the infestation is too large for hand-pulling and isn’t a good candidate for another containment strategy, covering the infestation with layers of burlap. The DNR isn’t advocating for a chemical treatment either as chemicals have not proven 100 percent effective. That’s because the algae does not have a vascular system to spread the poison beyond the immediate point of contact. Moreover, trying to kill the algae with poison sometimes has the opposite effect. The algae, sensing it is being attacked, doubles down and becomes even more aggressive.
· If starry stonewort was easy to contain and kill others would have figured it out by now. Sadly, the Cullen Chain now joins about 30 lakes in Minnesota and lakes in six other states that have been invaded. The algae was first found on North America’s east coast in 1978.
· The DNR has not ruled out management action but if it does occur it won’t be until 2025 at the earliest.
· The DNR will not accept the service of volunteer divers due to liability issues.
· As hard as it is to not do anything, there is evidence that when you leave starry stonewort alone it sometimes does not spread. That has been the case on Minnesota’s Big Winnibigoshish.
The Board recognizes this is an unsettling time. Since only the DNR can permit management actions, and for now the DNR isn’t permitting any, there’s not much the board can do. Please be vigilant as you take your docks out this fall and notify us if you spot what looks like an unusual form of vegetation. Ditto for this spring.
If you have questions, feel free to contact AIS Committee Chair Peter Miller or members Ann Beaver, C.B. Bylander, Carol Lindahl, John Maguire, Debi Oliverius or Randy Steenholdt.