Kill, Not Just Control Kill, Not Just Control EWMEWMEWMEWM

Big Marine Lake EWM ProjectBig Marine Lake EWM ProjectBig Marine Lake EWM ProjectBig Marine Lake EWM ProjectPresented by Mike BlehertPresented by Mike Blehert

Thank you to project Thank you to project partners:partners:

The Initiative Foundation, LessardThe Initiative Foundation, Lessard--Sams Sams Legacy grant programLegacy grant program

Washington County AIS prevention grantsWashington County AIS prevention grants Carnelian Marine St. Croix Watershed DistrictCarnelian Marine St. Croix Watershed District MN DNRMN DNR Blue Water ScienceBlue Water Science PLM Lake and Land Management Corp.PLM Lake and Land Management Corp. Many othersMany othersyy

Big Marine Lake (BML)Big Marine Lake (BML)Big Marine Lake (BML)Big Marine Lake (BML) Located in NE Washington CountyLocated in NE Washington County Located in NE Washington CountyLocated in NE Washington County BML is a clear and clean 1600 acre lake.BML is a clear and clean 1600 acre lake.

The native plant population is healthy andThe native plant population is healthy and The native plant population is healthy and The native plant population is healthy and diverse.diverse.Th BMLA f d i 2009Th BMLA f d i 2009 The BMLA was formed in 2009.The BMLA was formed in 2009.

First treatment First treatment -- 9.5 acres of EWM in 20099.5 acres of EWM in 2009 The littoral area is 1152 acres.The littoral area is 1152 acres. BML can support 150 to 200 acres of EWM BML can support 150 to 200 acres of EWM

according to Blue Water Science sediment according to Blue Water Science sediment analysisanalysis

Kill, Not Just Control EWM Kill, Not Just Control EWM ,, ControlControl: EWM turns brown and sinks in : EWM turns brown and sinks in

June and grows back in the late summerJune and grows back in the late summerJune, and grows back in the late summer.June, and grows back in the late summer.

KillKill EWM i k d d dEWM i k d d d KillKill: EWM sinks, decomposes and does : EWM sinks, decomposes and does not return the following spring(s??)not return the following spring(s??)

BMLA initiated a five year program to kill BMLA initiated a five year program to kill llll f EWM i 2015f EWM i 2015smallsmall areas of EWM in 2015.areas of EWM in 2015.

GoalGoal: Reduce EWM treatment to less than : Reduce EWM treatment to less than five acres/year by 2019.five acres/year by 2019.

Multiple Treatment ProtocolMultiple Treatment ProtocolMultiple Treatment ProtocolMultiple Treatment Protocol Increase herbicide Concentration ExposureIncrease herbicide Concentration ExposureIncrease herbicide Concentration Exposure Increase herbicide Concentration Exposure

Time (CET)Time (CET) 19 acres located in 8 elongated areas were 19 acres located in 8 elongated areas were gg

treated in 2015treated in 2015 2.5 ppm DMA4 applied by PLM at 7:00 pm on 2.5 ppm DMA4 applied by PLM at 7:00 pm on

June 10June 10 1.5 ppm Sculpin G applied by PLM at 7:00 1.5 ppm Sculpin G applied by PLM at 7:00

J 11J 11am on June 11am on June 11 These 8 areas had been treated almost every These 8 areas had been treated almost every

year since 2009 and 2011year since 2009 and 2011year since 2009 and 2011.year since 2009 and 2011.

2,42,4--D CET GraphD CET Graphpp

2016 2016 -- Changed to Renovate OTF Changed to Renovate OTF

Hybrid EWM more resistant to DMA4 than Triclopyr Hybrid EWM more resistant to DMA4 than Triclopyr (LaRue 2012)(LaRue 2012)( )( )

In small areas, Renovate OTF is 2 to 4 times more In small areas, Renovate OTF is 2 to 4 times more effective than liquid Triclopyr (Koschnick, et al 2010)effective than liquid Triclopyr (Koschnick, et al 2010)

Renovate accumulates in EWM roots 7.5 times more Renovate accumulates in EWM roots 7.5 times more than liquid (J.D. Vassios, 2014)than liquid (J.D. Vassios, 2014)than liquid (J.D. Vassios, 2014)than liquid (J.D. Vassios, 2014)

Renovate concentrates in the bottom 4 ft. of the water Renovate concentrates in the bottom 4 ft. of the water column, so deeper water can be treated as if it is 4 ft. column, so deeper water can be treated as if it is 4 ft. deep (Sepro Corp. and Koschnick, 2006, 2010)deep (Sepro Corp. and Koschnick, 2006, 2010)

PLM treated entire 9 ft. deep water column with PLM treated entire 9 ft. deep water column with Renovate, 1.5 ppm in AM and 1.0 ppm in PMRenovate, 1.5 ppm in AM and 1.0 ppm in PM

Expanded View of AreaExpanded View of Areapp

SPRING 2017 EXPECTTIONSSPRING 2017 EXPECTTIONSSPRING 2017 EXPECTTIONSSPRING 2017 EXPECTTIONS There is 4 to 6 acres of EWM in three otherThere is 4 to 6 acres of EWM in three other There is 4 to 6 acres of EWM in three other There is 4 to 6 acres of EWM in three other

areas.areas.

Expect 2 to 2.5 acres of EWM in the test Expect 2 to 2.5 acres of EWM in the test l t Th t i 90% d ti f EWM il t Th t i 90% d ti f EWM iplots. That is a 90% reduction of EWM in plots. That is a 90% reduction of EWM in

two years.two years.

Excellent progress toward achieving goal Excellent progress toward achieving goal p g g gp g g gof less than five acres by 2019.of less than five acres by 2019.