2017 Report - Invasive Species Control for Lac Courte Oreilles

 Prepared by Steve Umland, COLA AIS Coordinator

Background  

Lac Courte Oreilles (LCO) is a 5,040 acre lake with three public access points of which one is state owned. There approximately 640 residences on the lake’s shores along with resorts and campgrounds. The lake is heavily used by the property owners and visitors. Activities include scuba diving, swimming, snorkeling, boating, sailing, water skiing and of course world-class fishing. The Lac Courte Oreilles Band of Lake Superior Chippewa Indians relies on the lake for subsistence fishing, recreation and ceremonial purposes. The history of this lake is extensive. It is believed that the first map of larger North America included LCO when Lewis and Clark first published their journal documenting their famous expedition.

Control of all invasive species is critical to the health of this unique body of water. Specifically, the control of invasive aquatic species such as curly leaf pondweed (CLP) and Eurasian watermilfoil (EWM) is critical due to the transient nature of recreation and fishing boats. A unique problem for LCO involves the drainage dynamics for the 79,000 acre Upper Couderay River Watershed. Inlets to LCO include Little Grindstone Creek, Ring Creek, Osprey Creek, Ghost Creek, Spring Creek and Whitefish Creek. Eight lakes within the watershed drain into LCO - Big and Little Sissabagama, Sand Lake, Whitefish Lake, Grindstone Lake, Osprey Lake, and Big and Little Round Lake. LCO is, in fact, the dumping ground for the entire watershed’s problems when it comes to invasive species.

COLA’s goal for LCO is to reduce the threat of aquatic invasive species. Specific efforts include:

  • Preventing the introduction of aquatic invasive species.
  • Controlling the spread of CLP& EWM and reducing the extent of infestation.
  • Preservation of natural native plant species, which are outcompeted by uncontrolled spread of invasive species.
  • Continuation of an effective boat monitoring program for invasive species at boat landings.
  • Adoption of a shoreline monitoring volunteer program to look for invasive species on the lake’s shorelines. 

Review of COLA’s Effort to Control Invasive Species  

In July 2006, approximately 30 dense patches of CLP were discovered in Musky Bay. During the Fall of 2007, a pre-survey point intercept survey mapped CLP in Musky Bay. In Spring of 2008, a more complete survey was conducted, a plan was established, and permits were secured from the WDNR to chemically treat over 90 acres of CLP in Musky Bay. The granular chemical Aquathol-K was applied to the entire bay. That same Spring an infestation of CLP was also discovered and treated in Stucky Bay as well as Barbertown Bay. Since 2009, spot treatment and hand-pulling of CLP in all areas has been very successful.

The reduction of CLP infestation in Musky Bay has been remarkable, and WDNR has been very impressed with COLA’s dedication to controlling invasive species. From 2009 through 2015 there has been a steady reduction in both acres found and density of plants. In 2013, a different herbicide, Clearcast, was tested because excellent results were seen in other lakes, and Clearcast may be a bit easier on the native plants. Native plants have their own natural cycles, and they should repopulate areas where CLP has been eliminated. We are doing all we can to minimize inadvertent treatment effects on them.

Cost has also gone down. COLA works with independent contractors for herbicide applications and has spent as much as $45,000 per year during 2009-2012, to a low of approximately $10,000 in 2017. We have secured invasive species grants through WDNR to cover most of these costs for most years. Without additional financial support, however, from COLA and the Lac Courte Oreilles Foundation none of this would have been possible.

With the help of our shoreline volunteers, we now routinely pre-survey and treat known areas of infestation. Without this volunteer help we would have no chance of controlling invasive species in our lake!

Current Strategies  

During the last few years, we have hand pulled certain areas that we have chosen not to chemically treat. We would prefer to choose hand-pulling and scuba diving extraction of CLP to chemical treatment whenever possible.

In 2016, we treated less than ten acres of CLP in Musky Bay. We also chose to not treat CLP (<less one acre) in both Stucky Bay and Barbertown Bay.

In 2017, we noted a slight increase in CLP and treated it on the eastern edge of Musky Bay. We chose to not chemically treat CLP in Stucky Bay and Barbertown Bay. It was a test to see if infestation would remain relatively the same depending on hand-pulling efforts.

In 2016, a post-survey point intercept study of Little LCO discovered small areas of CLP and EWM. We mapped both and requested a quick response grant from WDNR to chemically treat these areas. Treatment occurred on June 2, 2017. After treatment, we also found another small patch of CLP near the Cty E bridge that spans the lake’s outflow. With a robust volunteer effort from cabin owners on Little LCO we hand pulled the entire plant pod.

The 2018 Spring pre-survey will give us a good test of the aggressive chemical and hand-pulling treatments that we implemented on both big and little LCO in 2017.

Outlook for the Future 

We have several goals as we look forward to 2018. Hopefully we will see a continued reduction of CLP acres in Musky Bay. However, we will most likely also be treating a small increase of CLP at the very end of Barbertown Bay.

A group of concerned lake owners contacted COLA this summer, 2017, expressing concern over the water quality of Stucky Bay. A cranberry operation is discharging high-nutrient water with excessively high-phosphorus concentrations directly into Stucky Bay. Algae blooms have been increasingly observed near this discharge outlet over the last few years. The question is whether COLA should continue spending our members’ dollars as well as those of the WDNR to treat an area that will continue to be a problem due to the discharge from this agricultural operation. Why keep throwing money at an invasive species problem when we can’t fix the source problem - the cranberry bog discharging into Stucky Bay?

It is essential for COLA to continue to be diligent and to aggressively deal with invasive species threatening our beautiful lake. We need to continue to encourage lake residents to volunteer to identify potential invasive species and identify potential problem areas. We will continue our Clean Boat/Clean Waters Program.

COLA will provide information for lakeshore owners by: 1) posting maps with areas of concern and treatment at boat landing bulletin boards; 2) periodic eBlasts about unusual events; 3) articles in Short Ears, Long Tales; and 4) website updates.

COLA has also created easy-to-use observation forms on its website so that anyone can readily report sightings of suspected invasive species. You can help COLA by using these Lake Observation Forms!