Working with partners to manage Invasive Aquatic Plants

Transcription

1 Working with partners to manage Invasive Aquatic Plants By: Chip Welling Coordinator, Management of Invasive Aquatic Species MnDNR To: State of Water conference Alexandria Date: 2016 April 15 S-o-W_2016_Apr_15-CW.ppt [April 12 draft]

2 Mission Minnesota Department of Natural Resources Work with citizens to conserve and manage the state's natural resources Copyright 2016, State of Minnesota, Department of Natural Resources

3 Mission Minnesota Department of Natural Resources opportunities for outdoor recreation, and commercial uses of natural resources in a way that creates a sustainable quality of life. Copyright 2016, State of Minnesota, Department of Natural Resources

4 Approach to management of invasive aquatic plants Prevention and Management Best management is to prevent a non-native aquatic plant from invading a lake If a non-native aquatic plant does invade a lake, what can we do?

5 Eurasian watermilfoil

6 Eurasian watermilfoil Dense mats can interfere with use of lakes Similar to, but can be more extensive than, those produced by natives Matted milfoil can displace natives

7 Management of Aquatic Plants in MN Before milfoil regulation of management for access After milfoil, regulation of management for various purposes Initiation of management Technical support Financial support

8 1992 Discovery

9 Milfoil in Bay Lake, Crow Wing County Initiators: MnDNR Bay Lake Improv. Assoc. Partners: Commercial SCUBA divers Commercial herbicide applicators Expectation: Eradication Selective control

10 Application of herbicide to control milfoil

11 SCUBA DIVER

12 1994 Two years after discovery

13 1996 Four years after discovery

14 Management of milfoil Bay Lake, Crow Wing County Expectation: Eradication Despite aggressive control, milfoil remained in Bay Lake and spread Same result in another 30 lakes treated from (Crowell 1999)

15 Eurasian watermilfoil and fluridone herbicide Fluridone and milfoil in Minnesota

16 Eurasian watermilfoil and fluridone herbicide Whole-lake treatment Cumulative limit 15% of the littoral area pesticide control of aquatic plants

17 Eurasian watermilfoil and fluridone herbicide Initiators: Company MnDNR Partners: Lake Association Commercial herbicide applicators Expectation: Eradication Selective control

18 Eurasian watermilfoil and fluridone herbicide 1992 Crooked Lake Dramatically reduced milfoil But no eradication Reduced native aquatic plants [Potential to reduce water clarity]

19 Partner: US Army Engineer Research and Development Center Army Corps of Engineers Aquatic Plant Control Research Program Inv_Aq_plnts_2012_mar_AERF.PPT

20 Why is this important? Results are publicly available Review by peers Readers can judge the results for themselves S-o-W_2016_Apr_15-CW.PPT If another researcher wants to replicate the work, they can

21 Fluridone vs. other herbicides Conc. Duration Trtmnt [ppb] of Expos. [days] Fluridone 4 6 > 60 wholelake 2,4-D, endothall, 1, spot diquat 2,000

22 Comparison between two lakes with Eurasian watermilfoil and treated with fluridone water clarity Year Schutz Lac Lavon [Secchi m] [Secchi m] Trt 0.6 Trt Trt

23 Management of curly-leaf pondweed Eutrophic to hypereutrophic lakes In Minnesota for 100 years More than 750 lakes Copyright 2016, State of Minnesota, Department of Natural Resources

24 Medicine Lake Secchi Depth and Chlorophyll-a Secchi Depth (m) /30/02 05/22/02 06/04/02 06/17/ /09/ /23/02 08/06/02 08/20/02 Secchi Depth Chlorophyll-a 09/10/ Chlorophyll-a (µg/l)

25 Curly-leaf pondweed and ecological benefits Initiators: ERDC MnDNR Partners: Lake Associations University of Minnesota Commercial herbicide applicators Companies

26 Curly-leaf pondweed and ecological benefits Expectations: Reduce interference with use Ecological benefits Increase water clarity Increase native plants Long-term reduction in CLP

27 Lake-wide control of curly-leaf pondweed Eutrophic and hypereutrophic lakes 3-5 years of successive lake-wide control Reduced interference with use in year of treatment Duration of reductions in CLP varied

28 Lake-wide control of curly-leaf pondweed Eutrophic and hypereutrophic lakes No reliable or significant increases in water clarity distribution of native submersed plants curly-leaf does not appear to be a major driver of water quality

29 Flowering rush

30 Flowering Rush First reported in 1968 In 35 bodies of water

31 Flowering rush in Detroit Lakes Becker County Initiators: Pelican River Watershed District City of Detroit Lakes Partners: US Army Engineer Research and Development Center Mississippi State University Commercial herbicide applicators MnDNR Expectation: Eradication Selective control

32 Flowering rush in Detroit Lakes Becker County Outcomes Screening of various herbicides Distribution and ecology in the lake Trials in the lake Submersed application of diquat can provide long-tern control

33 General template for management of Invasive Aquatic Plants Initiators: Lake Associations Local Units of Government Expectation: Reduce interference with use by partial lake treatment Partners: MnDNR Permits, Technical and Financial Assistance Commercial Herbicide Applicators or Harvestors Consultants [Local Units of Government]

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35 MnDNR s approach to management of Invasive Aquatic Plants Chip Welling, Invasive Species Program, Minnesota DNR Chip.welling@state.mn.us

36 10% in % in 2005 Pearl Lake, Stearns County Sentinel Lake

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38 Management of invasive aquatic plants Partial-lake treatment Focus: Areas with matted milfoil or curly that interferes with use Goal: Reduce interference with use Maintain reasonable amount of vegetation in the lake Maintain water clarity