Amnicon & Dowling Lakes Aquatic Plant Management Planning Project
Project Background • Aquatic Invasive Species Education, Prevention and Planning Grant Application – Submitted to WDNR in August 2011 – Awarded in October 2011 • $33,374.00 Total Project Cost – State Share = $25,030.00 – Amnicon-Dowling Lake Management District Share = $8,344.00 • Original End Date – June 30, 2013 – Extended End Date – December 31, 2013
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
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
Aquatic Plant Surveys - 2012 • Completed by Endangered Resource Services, LLC – Matt Berg, Proprietor • Final Aquatic Plant Survey reports completed in late 2012 and distributed to the Lake District
Highlights of the Plant Survey Work Curly-leaf Pondweed (CLP) Eurasian water milfoil (EWM)
Curly-leaf Pondweed in Amnicon • 5.4 acres in 2012 • 1.4% 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
More AIS Reed Canary Grass Purple Loosestrife Chinese Mystery Snails
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 -3.66 species/site -7 extremely high value or sensitive species -Ave CC value = 6.8 out of 10
Wild Rice Widely scattered in south and southwest bays, none dense or harvestable 23 survey points with wild rice
Native Plants – Amnicon Not so Great… Average Density 2.21 out of 3
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 -1.79 species/site -Only 3 high value or sensitive species -Ave CC value = 6.3 out of 10 -No wild rice
Native Plants – Dowling Not so great… • Not much vegetation in the lake Nitella sp. Watershield
Current Water Quality – Amnicon & Dowling • Amnicon – Plant dominated – Ave. water clarity = 6-ft Amnicon – Ave. Total Phosphorus = 24.6 ug/l – Ave. Chlorophyll a = 8.3 ug/l • Dowling – Algae dominated Dowling – Ave. water clarity = 3.6 ft – Ave. Total Phosphorus = 35.5 ug/l – Ave. Chlorophyll a = 18.7 ug/l
Trophic Status X Amnicon X Dowling http://www.hillsborough.wateratlas.usf.edu/shared/learnmore.asp?toolsection=lm_tsi
Historic Water Quality – Amnicon & Dowling Top-Bottom Paleocore • Amnicon • Dowling – Top (current) TP: 26 ug/L – Top (current) TP: 80 ug/L – Bottom (historic) TP: 25 – Bottom (historic) TP: 26 ug/L ug/L – Top: > aquatic vegetation – Top: < aquatic vegetation – Bottom: < aquatic – Bottom: > aquatic vegetation vegetation
Public Use Survey 300 surveys mailed out, 95 returned (31.6%) • Amnicon • Dowling – 59 surveys returned – 36 surveys returned – Residency – Residency • Permanent – 29 • Permanent – 10 • Undeveloped Land – 1 • Undeveloped Land – 4 • 2 nd Home – 7 • 2 nd Home – 3 • Cabin – 23 • Cabin – 19 • Mobile Home – 1 – Ave. Time on Lake – Ave. Time on Lake • 26.4 years – Minimum – 1 year • 21.3 years – Maximum – 90 years – Minimum – 1 year – Maximum – 84 years
Top Lake Uses • Dowling • Amnicon – Swimming – Swimming – Fishing – Rest/Relaxation – Rest/Relaxation – Fishing – Quiet Sports – Wildlife viewing – Wildlife viewing – Quiet Sports • Changes • Changes – Slightly “worsened” – Split between “no changes” and – Greatest Changes “worsened” • Game fishing, pan fishing, and swimming – Greatest Changes • Game fishing, pan fishing, motorized sports, and swimming
Lake Characteristics • Amnicon • Dowling – Rooted vegetation, green – Green scum, use of scum, motorized boats, jetskis, and noise pollution and use of jetskis increased increased – Public use and garbage in – Wild rice decreased the lake decreased • Septic System Check • Septic System Check – 55.9% would support – 44.4% would support – 18.6% would oppose – 11.1% would oppose • Water Quality • Water Quality – 61% Fair, 15% Good, – 28% Fair, 14% Good, 20% Poor 47% Poor
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.
Knowledge of Aquatic Invasive Species LOW LOW LOW At least 55.8% would attend an SOME LOW AIS Training Session! LOW SOME LOW
Support for Aquatic Plant Management Alternatives • Dowling • Amnicon – Most Support – Most Support • Physical removal • Mechanical • Mechanical harvesting harvesting • Physical removal – Least Support – Least Support • Chemical herbicides • No management • Biological control • Chemical herbicides – Who Should Be – Who Should Be Responsible? Responsible? • ADLMD • ADLMD • WDNR • WDNR
Wild Rice 2010 Ceded Territory Manoomin Inventory ERS, August 2012 SEH, August 2012
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
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
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
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
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
The End Questions?
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