Amnicon & Dowling Lakes Aquatic Plant Management Planning Project

Transcription

1 Amnicon & Dowling Lakes Aquatic Plant Management Planning Project

2 Project Background Aquatic Invasive Species Education, Prevention and Planning Grant Application Submitted to WDNR in August 2011 Awarded in October 2011 $33, Total Project Cost State Share = $25, Amnicon-Dowling Lake Management District Share = $8, Original End Date June 30, 2013 Extended End Date December 31, 2013

3 Objective of the Project Complete an Aquatic Plant Management (APM) Plan for both lakes Approved by both the ADLMD and the WDNR What is an Aquatic Plant Management (APM) Plan? A working document used to guide appropriate aquatic plant management A tool for the Lake District to use to educate and inform property owners and lake users A valuable exercise in planning to help understand the complexities in dealing with aquatic plants DNR required document to complete aquatic plant management including non-native invasive species and native plants

4 Parts of the Project Aquatic plant survey on both lakes Early season curly-leaf pondweed and Eurasian water milfoil Mid season all aquatic plants Water quality review Current historical paleocore Gather public input Lake Use Survey Draft APM Plan comment Aquatic Invasive Species (AIS) Watercraft inspection, AIS monitoring, AIS education and outreach, purple loosestrife beetle assessment

5 Aquatic Plant Surveys Completed by Endangered Resource Services, LLC Matt Berg, Proprietor Final Aquatic Plant Survey reports completed in late 2012 and distributed to the Lake District

6 Highlights of the Plant Survey Work Curly-leaf Pondweed (CLP) Eurasian water milfoil (EWM)

7 Curly-leaf Pondweed in Amnicon 5.4 acres in % of total lake surface area Found in 4-9 ft of water Monotypic at 6-ft Exploits disturbed areas Fills in where other plants begin to thin Likely impacting wild rice growth

8 More AIS Reed Canary Grass Purple Loosestrife Chinese Mystery Snails

9 Native Plants Amnicon The Good! 501 points sampled, Maximum depth of plant growth = 11-ft, (43.5%) of total surface area -Littoral Zone = 56% of the lake -60 different plant species species/site -7 extremely high value or sensitive species -Ave CC value = 6.8 out of 10

10 Wild Rice Widely scattered in south and southwest bays, none dense or harvestable 23 survey points with wild rice

11 Native Plants Amnicon Not so Great Average Density 2.21 out of 3

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13 Native Plants Dowling The Good but not so great 253 points sampled, Maximum depth of plant growth = 7-ft, 11.5% of total surface area, only 30% of littoral zone -Littoral Zone = 38% of the lake -33 different plant species species/site -Only 3 high value or sensitive species -Ave CC value = 6.3 out of 10 -No wild rice

14 Native Plants Dowling Not so great Not much vegetation in the lake Nitella sp. Watershield

15 Current Water Quality Amnicon & Dowling Amnicon Amnicon Plant dominated Ave. water clarity = 6-ft Ave. Total Phosphorus = 24.6 ug/l Ave. Chlorophyll a = 8.3 ug/l Dowling Dowling Algae dominated Ave. water clarity = 3.6 ft Ave. Total Phosphorus = 35.5 ug/l Ave. Chlorophyll a = 18.7 ug/l

16 Trophic Status X Amnicon X Dowling

17 Historic Water Quality Amnicon & Dowling Top-Bottom Paleocore Amnicon Top (current) TP: 26 ug/l Bottom (historic) TP: 25 ug/l Top: > aquatic vegetation Bottom: < aquatic vegetation Dowling Top (current) TP: 80 ug/l Bottom (historic) TP: 26 ug/l Top: < aquatic vegetation Bottom: > aquatic vegetation

18 Public Use Survey 300 surveys mailed out, 95 returned (31.6%) Amnicon 59 surveys returned Residency Permanent 29 Undeveloped Land 1 2 nd Home 7 Cabin 23 Ave. Time on Lake 26.4 years Minimum 1 year Maximum 90 years Dowling 36 surveys returned Residency Permanent 10 Undeveloped Land 4 2 nd Home 3 Cabin 19 Mobile Home 1 Ave. Time on Lake 21.3 years Minimum 1 year Maximum 84 years

19 Amnicon Swimming Rest/Relaxation Fishing Wildlife viewing Quiet Sports Changes Split between no changes and worsened Greatest Changes Game fishing, pan fishing, motorized sports, and swimming Top Lake Uses Dowling Swimming Fishing Rest/Relaxation Quiet Sports Wildlife viewing Changes Slightly worsened Greatest Changes Game fishing, pan fishing, and swimming

20 Lake Characteristics Amnicon Rooted vegetation, green scum, motorized boats, and use of jetskis increased Wild rice decreased Septic System Check 55.9% would support 18.6% would oppose Water Quality 61% Fair, 15% Good, 20% Poor Dowling Green scum, use of jetskis, and noise pollution increased Public use and garbage in the lake decreased Septic System Check 44.4% would support 11.1% would oppose Water Quality 28% Fair, 14% Good, 47% Poor

21 What Most Affects Water Quality? Amnicon Dowling Faulty septic systems Faulty septic systems Dead and dying Dead and dying vegetation vegetation Lawn runoff and Others shoreland erosion Water level Others Water level, road next to lake, AIS, flooding The Lake Community generally supports removing AIS from the system, providing property improvement incentives, dredging, and update of septic systems.

22 Knowledge of Aquatic Invasive Species LOW LOW LOW At least 55.8% would attend an SOME LOW AIS Training Session! SOME LOW LOW

23 Amnicon Most Support Mechanical harvesting Physical removal Least Support No management Chemical herbicides Who Should Be Responsible? ADLMD WDNR Support for Aquatic Plant Management Alternatives Dowling Most Support Physical removal Mechanical harvesting Least Support Chemical herbicides Biological control Who Should Be Responsible? ADLMD WDNR

24 2010 Ceded Territory Manoomin Inventory Wild Rice ERS, August 2012 SEH, August 2012

25 Conclusions Property owners on both lakes support implementing aquatic plant management actions Management of CLP is necessary on Amnicon Management of nuisance native aquatic vegetation is necessary on Amnicon Protection of existing beds of aquatic plants and possible reestablishment of aquatic plants is necessary on Dowling Greater AIS education effort on both lakes is needed to help protect the lakes from future introductions Wild rice protection will impact all aquatic plant management options; at least on Amnicon

26 Preliminary Aquatic Plant Management Recommendations Continue AIS prevention and monitoring efforts on both lakes Provide greater AIS Education efforts for property owners on both lakes Continue water quality monitoring on both lakes Protect and enhance wild rice waters in Amnicon Possibly reestablish/introduce wild rice on Dowling Continue purple loosestrife and other AIS management efforts Implement aquatic plant management actions that will maintain or improve water quality in both lakes

27 Aquatic Plant Management Actions Encourage/support physical removal of nuisance aquatic plants and aquatic invasive species NR 107 It is legal to remove aquatic vegetation from the lake in an area up to 30-ft wide without a permit provided all plant material is removed from the lake Physical removal of AIS is not restricted provided it is removed from the lake Mechanical harvesting Of CLP in areas where wild rice will not be impacted Of nuisance aquatic vegetation in designated navigation channels Of access corridors between docks and open water or navigation channels

28 Management Actions continued: Work with Tribal Resources to determine a wild rice restoration plan in Amnicon Re-seeding in CLP harvesting areas Consider dredging of navigation corridors if aquatic plant harvesting does not provide adequate relief Will require a separate dredging plan to be devised Implement a more complete water level monitoring and management program Lake level monitoring Stream flow between lakes

29 Management Actions continued: Provide education materials related to shoreland improvements and best management practices Design and implement a shoreland improvement incentives program Design and installation of rain gardens, buffer zones, shoreland restoration, and runoff diversion projects Individual property owners Roadway right-of-ways Consider comprehensive lake management planning for water quality Near shore and watershed runoff Septic system survey Internal loading

30 The End Questions?