Monday morning members of the Long Lake Protection and Rehabilitation District (LLPRD) met with environmental consultants Onterra, several members of the Department of Natural Resources and other aquatic plant specialists to discuss expectations and issues that may surround treating curly leaf pondweed on Lost Lake. DNR lakes biologist Kevin Gauthier facilitated the meeting.
"The purpose of the meeting is to have a discussion with the DNR at their request to discuss the herbicidal treatment permit that has been applied for by the Lost Lake District," LLPRD chairman Jim Ulett said to begin the meeting.
The environmental consultant company Onterra was represented by Tim Hoyman and Eddie Heath, who had drawn up a summary overview of the curly leaf pondweed and Eurasian watermilfoil findings in Lost Lake for the DNR and the lake district.
"This is a pretty typical working meeting," Gauthier said, setting up the meeting for those in attendance. "Onterra was hired by the district to put together the summary report that has a proposed curly leaf pondweed treatment in it. As I do with a lot of products that we get, I send it around for review because any time there is a permit or, in this case, there is potentially an early response grant involved and there could be some reimbursements involved with grants as well. So we have it reviewed."
He said from there he gets comments from various entities and he thought it would be a good idea to get all three groups (DNR, Onterra and LLPRD) together to get everyone on the same page. Gauthier made it clear no policy decisions or permit decisions would be made at this meeting. It was strictly informational for all involved. The hope was to come up with a summary report on which all parties could agree and move forward from there.
One of the difficult things, most agreed, is curly leaf pondweed (CLP) is not one of the invasive species that a great deal is known about. There has been a great deal of research and study done on Eurasian watermilfoil (EWM), which is another invasive plant, but that is not the case for CLP. Much like EWM, CLP does not always create the worst case scenario in every lake. In some lakes it has all but died off on its own. On other lakes, it grows and expands. What conditions cause each of these scenarios is somewhat unclear, although the plant does seem to do better where there is some current. As Susan Knight from Trout Lake Station mentioned, however, there is at least one instance locally where CLP fared poorly when current became more swift on one particular lake.
One concern is what would happen after treatment when the CLP was knocked down. If this would allow EWM to move into the place, it could be trading one problem for another.
"If we kick people out of the apartments, other people can move in," said Tim Hoyman from Onterra in an analogy to help others understand how the plant community might respond to CLP being knocked down in the bay where it has taken hold. Another concern was the impacts to the native plant community. A chemical treatment for CLP would also likely impact native plants, as the chemical does not differentiate between native and invasive species of plants. In order to address the CLP problem, however, it was clear all involved may have to accept some collateral damage in the way of native plants. In other treatment scenarios, native plants have come back after chemical treatments, but there is no clear timeline and each lake is different, Knight said.
"We might just have to accept some collateral damage," Marv Anderson of LLPRD said. "We have to take that because, 30 acres, you can't go through it with a kayak. I go back and say, OK, the collateral damage is going to happen. How much does that play into the decision to treat the curly leaf pondweed and maybe we just have to take our lumps?" Gauthier agreed decisions such as that are what makes it difficult, and getting all involved on the same page is important for that reason.
"Just because we aren't measuring certain biota doesn't mean they aren't being affected, either," Gauthier said. "We try to manage what risks are out there." All agreed that using an herbicide always comes with risks. In this case, however, Onterra firmly believed the risks that may be associated with treatment were such that treatment of the CLP was a better option than non-treatment. Members of the lake district agreed.
Onterra was already working with the lake district and monitoring the lake on a regular basis when they found CLP three years ago. This bodes well for the lake, as cutting back an invasive population that is found early is usually easier than one that has been established for a year. With the case of CLP, the plant sheds turions in midsummer before dying back. These turions fall into the substrate and create new plants the next year. This can make treating established populations very difficult. It is not known with certainty how long the turions can remain viable in the soil, but plants growing from a turion that has been in soil for a few years is not out of the question. For that reason, once the plants have been established for a long time, and the substrate has the potential to become loaded with turions, treatment is much less effective. Still, in the case of Long Lake, treatment is recommended for five to seven years. Treatment would occur in the spring before turions form on the plants. This would kill the plants growing in that treatment year. In subsequent years, as more plants sprout from the turions in the soil, treatments would be done again to kill those plants. While CLP will never be completely eliminated from the lake, this treatment plan gives the best hope of knocking it down to a level that would be acceptable for the lake's stakeholders.
"Our initial recommendation was (monitoring only), in some areas of the state, potentially more so in northern Wisconsin, it does not act invasively and does not cause ecosystem impacts or impact lake stakeholders," said Eddie Heath from Onterra. Monitoring was recommended and as the CLP population grew, it was clear some management decisions would likely need to be made soon. Now it has come to the point where the district and other stakeholders on and around the lake feel it is time to do something about the problem. Onterra was in agreement and the summary report was created to explain the issues on the lake as well as what a chemical treatment may be able to do. Hand-pulling of CLP was discussed as a possibility for some of the smaller patches around the lake and Onterra said they would look into that possibility as part of their new summary report. Several difficulties with that type of management were discussed, but it was decided the option would at least be kept open to see if it was a viable treatment strategy for smaller stands of CLP.
The meeting ended with an overview, to be sure all involved were in agreement of the outcome of the conversation. Gauthier summed up the expectations moving forward.
"I think there's a couple things we can add," he said. "We talked about adding some metrics for the qualitative scale for everybody. And then also, a second thing would be to pick a spot to try some hand pulling, and what sort of metric might go on there, but I know that's tough when it gets to a small scale."
He went on to talk about a survey that would go on this spring to check the growth that might be happening as well as the point intercept survey that would take place this summer. Native plants could also be taken into account during the summer survey to get a clearer idea of what is in the lake, what the abundance is, and possibly what impacts CLP treatment may have.
Concentration monitoring post-treatment was also discussed. This monitoring will let stakeholders know how quickly the chemical treatment dissipates and if there would be any effects downstream. The group discussed temporarily lowering the lake level just enough to have the minimum flow going through the dam directly after treatment. That would be discussed further, but Ulett said it would be possible within certain parameters.
Monitoring curly leaf pondweed in this instance may have statewide implications, Gauthier said. Because there is much to learn about CLP, there may be other help for the lake district should they undertake something such as turion monitoring as part of the CLP management plan. Turion monitoring is quite labor intensive.
"What we're talking about is taking samples with a dredge," Hoyman said. "It scoops up some sediment and put it these trays and shake it out, kind of like you're panning for gold and then you count the turions."
Getting a clean scoop, he said, is difficult on lakes such as Long that have a lot of plant growth. Another issue involves getting a large number of scoops with zero turions and then getting one scoop with a huge number in it. He said while Onterra is always willing to do the science part, the amount of labor that goes into turion monitoring in that fashion is huge for the amount of data received.
"Let's say we have all the money in the world," Hoyman said. "I'm still not convinced that it's a good methodology. I don't know if we learn that much. But I promise you we'll look at it." Due to the statewide interest in learning about CLP, there may be some other resources available to help with that sort of monitoring, but that would be discussed at a later date and was not a sure thing by any means.
"Sometimes when you bring people together and you talk through issues, you land on something that has statewide significance," Gauthier said. "There's an early response grant, there's our staff, there's Trout Lake. Sometimes things just line up and we say, 'hey we can get something done.' Sometimes that doesn't happen, but that was just brought up - it's not a requirement, but just for discussion." He agreed the Department could look into it, but it was left at that.
All parties agreed they had a better understanding of the process and what was needed, moving forward, to go further in the permitting process. Onterra would look at the different things discussed during the meeting and add those recommendations into the plan.
Beckie Gaskill may be reached via email at email@example.com.