Crooked Lake LVMP Shortform 3 2 2013 - freshwatersci.com · EWM!to!other!water!bodies.!The!CLAA ......

Crooked Lake, Anoka County (#02-‐0084) 1 | P a g e

Lake Vegetation Management Plan DNR Short Form

Variance Requested by Cooperator Waiver of Signature Requirement Requested by Cooperator Variance Approved (see Section 8)

Management Target(s):

Eurasian watermilfoil Curlyleaf pondweed Other______________________

Section 1: Lake Information Name: Crooked Surface Area: 118 acres County: Anoka Littoral Area: 86 acres DOW Number: 02-‐0084 Max Depth: 26 feet Fisheries Area: East Metro Mean Depth: 9 feet Classification: General Development Cooperator(s): (1) Crooked Lake Area Association (CLAA)

(2) Coon Creek Watershed District (CCWD) (3) Freshwater Scientific Services, LLC

Section 2: Water Quality and Plant Community A. Water Quality: (as reported by MPCA)

Mean (May-‐Sept) Observations Monitored Years Total Phosphorus 31 µg/L 50 2003-‐2012 Chlorophyll-‐a 7 µg/L 33 2003-‐2012 Secchi Depth 7 ft 111 2003-‐2012

B. Plant Community: (Table 1) The Minnesota DNR conducted plant surveys in 2001, 2002, 2003, 2004, 2007,

and 2012 (Aug); The CLAA hired a contractor (PLM, Lake & Land Management Inc.) to conduct point-‐intercept (PI) vegetation surveys in 2010, 2011, and 2012 (Apr). Most Recent Survey: Aug 2012 Total Points Sampled: 82 Littoral Points (≤15ft): 82 Max Depth of Growth: 15 ft



Table 1. Percent occurrence of plants observed during surveys of Crooked Lake (Aug; 2001 to 2012). Reported values for curlyleaf pondweed reflect spring values (May-‐Jun) when available. Plant taxa are generally listed from most common to least within each growth form category.

Taxonomic Name Common Name 2001 2002 2003 2004 2007 2010 2011 2012 SUBMERSED PLANTS Myriophyllum spicatum Eurasian watermilfoil 45 22 0 0 27 56 56 37 Chara spp. Muskgrass 32 40 53 54 27 17 15 13 Ceratophyllum demersum Coontail 9 18 6 2 18 5 21 21 Potamogeton amplifolius Large-leaf pondweed 4 2 3 4 9 9 16 Potamogeton illinoensis Illinois pondweed 3 6 1 1 17 Stuckenia pectinata Sago pondweed 14 2 30 14 10 13 8 4 Potamogeton crispus Curlyleaf pondweed 5 1 19 38 18 1 2 Zanichellia palustris Horned pondweed 5 2 26 42 Myriophyllum sibiricum Northern watermilfoil 19 3 1 9 Potamogeton zosteriformis Flat-stem pondweed 2 3 7 6 9 Najas spp. Bushy pondweed 9 1 Potamogeton richardsonii Claspingleaf pondweed 2 6 Eleocharis acicularis Needle spike rush 2 Zosterella dubia Water stargrass 1 Utricularia spp. Bladderwort 1 Vallisneria americana Wild celery 1 FLOATING PLANTS Nymphaea odorata White waterlily 6 10 11 Nuphar variegata Yellow waterlily 3 2 EMERGENT PLANTS Typha sp. Cattail 13 8 P Schoenoplectus spp. Bulrush 4 2 2



Section 3: Public Input Process

Communication with Homeowners: There are approximately 120 shoreline properties surrounding Crooked Lake. The Crooked Lake Area Association (CLAA) has had consistent and dedicated involvement from its members for many years. Public input and involvement with lake activities and management projects include:

Public Meetings: • CLAA bi-‐annual general meetings; shoreline owners are invited and meeting is open to the public • CLAA monthly board meetings with representatives from shoreline owners • All residents of the Crooked Lake watershed are eligible for membership in CLAA

Newsletters and Education: • CLAA bi-‐annual newsletters to CLAA members and homes in Crooked Lake watershed (420 homes) • Distribution of invasive species info door hangers and handouts at the public boat landing

Communication with Agencies and Organizations: • Close coordination & communication with Coon Creek Watershed District (CCWD) staff • Communication with Anoka Conservation District, City of Andover, and City of Coon Rapids • Coordination & communication with Conservation Minnesota organization • Coordination & communication with DNR Invasive Species personnel

Section 4: Problem Identification

Eurasian watermilfoil (EWM) 1. EWM interferes with use of the lake 2. EWM displaces native aquatic plants 3. Research Needed

a. CLAA and CCWD conducted a plot study in 2011 and 2012 to identify which native plants would likely reestablish in areas where EWM was controlled (conducted by Freshwater Scientific Services, LLC; report available at http://www.fixmylake.com). The next step in this project is to evaluate whether controlling EWM in larger areas promotes those native plants.

b. Need further evaluation of whether large-‐scale herbicide control of EWM can provide long-‐term control of EWM and increase the frequency, abundance, and diversity of native plants

Curlyleaf Pondweed (CLP) 4. CLP interferes with use of the lake 5. CLP displaces native aquatic plants 6. Research Needed

a. Need further evaluation of whether herbicide control of CLP can prevent increased CLP in lakes where EWM is being actively managed.



Section 5: Goals & Objectives for Plant Management

1. (EWM and CLP) Control EWM and CLP to reduce interference with recreational lake use a. Reduction in frequency and abundance of EWM in August* b. Reduction in area of surface matted EWM (mapped in August with GPS unit)* c. Maintain (or reduce) the low frequency and abundance of CLP*

2. (Native Plants) Protect and promote healthy native plant community in Crooked Lake a. Native plant frequency and diversity shall be maintained or increased (PI surveys)*

3. (Research) Evaluate effectiveness of long-‐term, large-‐scale EWM control

a. Research-‐quality data on EWM frequency and abundance (PI) b. Communication of results to MDNR staff

4. (Research) Evaluate whether 2011-‐2012 plot study was a good indicator of which native plants

were most likely to increase in frequency and abundance after EWM control. Such information may be useful in future projects by providing a way to predict native plant response in individual lakes before conducting large-‐scale herbicide treatments.

a. Compare observed native plant recovery (PI) with predictions from plot study* b. Communication of findings to MDNR staff

(* Measurable outcomes)

Section 6: Alternative Methods Considered This section is needed to meet the requirements of MNG87D000 Vegetative Pests and Algae Control Pesticide General Permit; issued by the Minnesota Pollution Control Agency to meet requirements of the National Pollution Discharge Elimination System.

Target Pest: Eurasian watermilfoil (EWM)

No Action (EWM): “No action” would likely allow the current widespread, dense EWM to persist or increase in the lake. Consequently, recreational impairment would not be reduced and EWM would continue to displace native plants. Furthermore, this would increase the likelihood of transport of EWM to other water bodies. The CLAA has decided that “no action” is not a feasible option for EWM.

Prevention (EWM): The MN DNR has an AIS Prevention program to stop the spread of invasive species. This includes designating infested waters, posting signage, enforcing AIS laws, inspecting and educating boaters at water accesses, and decontaminating water equipment as needed. In addition, the CLAA periodically conducts AIS boat inspections at the Crooked Lake boat launch (prevents EWM transport).



Mechanical/Physical Methods (EWM): Hand-‐Pulling: In 2011 and 2012, the CLAA and CCWD hired Freshwater Scientific Services to conduct hand-‐pulling of EWM in test plots to evaluate native plant response in areas where EWM was controlled. Hand-‐pulling of EWM from these plots was very time intensive and required diving. Given the amount of time and effort required to hand-‐pull EWM in these small plots (total area = 0.2 acres), the CLAA has determined that hand pulling is not a feasible option for controlling the 50 acres of EWM in the lake. If EWM is greatly reduced in frequency and abundance in the future, the CLAA will consider hand-‐pulling as a control strategy.

Cutting/Mechanical Harvesting: Although cutting and harvesting can maintain navigational channels through dense EWM, it only offers a temporary fix and can negatively impact native plants in the harvested areas (non-‐selective removal). Furthermore, cutting and harvesting can spread EWM fragments, possibly resulting in expansion of the area infested with EWM. Consequently, the CLAA does not consider cutting or harvesting to be a good option for EWM control in the lake.

Cultural Methods (EWM): These are manipulations of the habitat to increase pest mortality by making the habitat less suitable to the pest. For example, one might dredge a lake to make it too deep for invasive aquatic plants to obtain enough light to survive. Generally, such approaches are infeasible due to high cost and the potential to reduce the abundance of desirable native plants. Biological Control Agents (EWM): In 2012, Freshwater Scientific Services, LLC observed evidence of milfoil weevil damage (blackened EWM stems) in some areas of the lake, and documented the presence of a few adult milfoil weevils on EWM plants. However, Freshwater staff did not conduct a systematic survey to determine the abundance of weevils in the lake. The persistence of widespread, dense EWM in the lake, despite the presence of weevils, suggests that additional biological control would not greatly reduce EWM in the lake. If future research indicates that biological control may be feasible and effective, the CLAA will consider using biological control agents to manage EWM.



Target Pest: Curlyleaf Pondweed (CLP)

No Action (CLP): “No action” would likely allow CLP to persist or increase in the lake. Consequently, recreational impairment would not be reduced and CLP would continue to displace native plants in some areas of the lake. Furthermore, this would increase the likelihood of transport of CLP to other water bodies. The CLAA has decided that “no action” is not a feasible option for CLP.

Prevention (CLP): The MN DNR has an AIS Prevention program to stop the spread of invasive species. This includes designating infested waters, posting signage, enforcing AIS laws, inspecting and educating boaters at water accesses, and decontaminating water equipment as needed. In addition, the CLAA periodically conducts AIS boat inspections at the Crooked Lake boat launch (prevents CLP transport). Mechanical/Physical Methods (CLP): Hand-‐Pulling: Hand pulling is not a feasible option for controlling the widespread but sparse CLP in the lake. If CLP is found to be isolated to only a few small patches in the future, the CLAA will consider hand-‐pulling as a potential control strategy.

Cutting/Mechanical Harvesting: Although cutting and harvesting can maintain navigational channels through dense CLP, it only offers a temporary fix and can negatively impact native plants in the harvested areas (non-‐selective removal). Given the current low abundance of CLP in the lake, the damage to native plants would likely outweigh the benefits of the CLP removed. Consequently, the CLAA does not consider cutting or harvesting to be a good option for CLP control in the lake. If CLP frequency and abundance increase substantially in the future, the CLAA will consider mechanical harvesting as a control strategy for CLP.

Cultural Methods (CLP): These are manipulations of the habitat to increase pest mortality by making the habitat less suitable to the pest. For example, one might dredge a lake to make it too deep for invasive aquatic plants to obtain enough light to survive. Generally, such approaches are infeasible due to high cost and the potential to reduce the abundance of desirable native plants. Biological Control Agents (CLP): There are currently no biological control agents that effectively control CLP. If future research indicates that biological control may be feasible and effective, the CLAA will consider using biological control agents to manage CLP.



Section 7: Proposed Management Actions The CLAA plans to control delineated areas of dense EWM and CLP in Crooked Lake using selective herbicides and selective timing.

Note: The treatment protocols detailed below may change as new information becomes available. Any changes will be added to this plan as appendices and incorporated into the APM permits. Upon the next update of this plan, any appended changes will be incorporated into the main document. Management Option 1. Large-‐scale spot herbicide treatments to control EWM

Herbicide Control: Treatment areas will be determined by delineation and DNR inspection

Proposed Actions: Selective control of EWM with application of 2,4-‐D or triclopyr to delineated areas

Benefits: (1) Greatly reduced impairment of lake use (2) Reduced competition with native plants on a lake-‐wide scale

Risks: (1) Commercial applicator has indicated that Crooked Lake currently supports hybridized milfoil

(M. spicatum x M. sibiricum) that may grow slightly later than EWM. The CLAA and CCWD are committed to working with the DNR and applicators to control both hybrid milfoil and EWM by using the most appropriate herbicide formulation, dose, or timing of application.

(2) Auxin-‐mimic herbicides (2,4-‐D and triclopyr) can also affect lilies and some other plant species. Given that Crooked Lake has been treated with these herbicides in the past, it appears that the current native plant community is dominated by plants that are generally less susceptible to these herbicides than EWM, and will thus likely persist and expand if treatments effectively reduce EWM in the lake. Treatment protocols will include provisions to minimize damage to lilies and other sensitive plant species.

Adaptive Management: The CLAA and CCWD are committed to striking a balance between controlling invasive aquatic plants and maintaining a healthy and diverse native plant community. Accordingly, they will pursue other management options if large-‐scale herbicide treatments reduce the overall frequency, abundance, or diversity of native plants in the lake, or fail to effectively control EWM. These options may include smaller spot treatments, other herbicides, biological control, or mechanical control. Furthermore, the CLAA and CCWD are committed to minimizing the area treated as the frequency and abundance of invasives are reduced.



Management Option 2. Herbicide treatments to control CLP Herbicide Control: Treatment areas will be determined by delineation and DNR inspection.

Proposed Actions: Selective control of CLP with application of endothall or imazamox to delineated areas of nuisance CLP growth

Benefits: (1) Minimize impairment of lake use due to dense CLP (2) Reduced competition with native plants (3) Prevent release of phosphorus upon CLP senescence

Risks: (1) Endothall and imazamox may harm some native aquatic plants if applied at an inappropriate

dosage or timing. The CLAA and CCWD are committed to working with the DNR and herbicide applicators to ensure that any herbicide use occurs at the most appropriate dose and time of year to maximize control of CLP while minimizing impacts to native aquatic plants.

Adaptive Management: The CLAA and CCWD are committed to striking a balance between controlling invasive aquatic plants and maintaining a healthy and diverse native plant community. Accordingly, they will pursue other management options if herbicide treatments for CLP reduce the overall frequency, abundance, or diversity of native plants in the lake, or fail to effectively control CLP. These options may include selecting a more optimal dosage or formulation of herbicide, biological control, or mechanical control. Furthermore, the CLAA and CCWD are committed to minimizing the area treated as the frequency and abundance of invasives are reduced. Individual Near-‐Shore Permit Standards (new permits after lake-‐wide treatment) Chemical Treatment of Submersed Plants: Limited to an area no greater than 50 feet wide along shore (or half of lake frontage, whichever is less) x 50 feet lakeward. Any permit applications received from riparian landowners for chemical treatment of native submersed plant after the lake-‐wide treatment will be considered on an individual basis. Removal of native submersed vegetation will be limited to only that area necessary to allow reasonable use. No removal of sparse native vegetation through the use of chemicals will be permitted. Permit requests are subject to inspection and the aforementioned limits are maximums allowed for native species control.



Section 8: Variance Provisions & Approval (check all that apply) The commissioner may issue APM permits (and IAPM permits) with a variance from one or more of the provisions of parts 6280.0250, subpart 4, and 6280.0350, except that no variance may be issued for part 6280.0250, subpart 4, items B and C. Variances may be issued to control invasive aquatic plants, protect or improve aquatic resources, provide riparian access, or enhance recreational use on public waters (6280.1000, subpart 1). Variance(s) and Justification(s)

Application of pesticides to control submersed vegetation in more than 15% of the littoral area (M.R. 6280.0350, Subp. 4, A)

Justification: (1) EWM currently dominates ~50% of Littoral Area: In recent years, EWM has formed dense, surface-‐

matted growth in 30 to 50% of the lake. A variance would provide substantial recreational and ecological benefits by (1) minimizing recreational impairment by EWM and CLP, (2) promoting the survival, growth, and spread of native submersed aquatic plants, and (3) increasing the likelihood of effective EWM and CLP control by allowing for larger contiguous areas to be treated (variance to M.R. 6280.0350, Subp. 4, A).

(2) CLP may increase substantially if EWM is reduced: In the early 2000’s, EWM in the lake was greatly reduced after lake-‐wide fluridone treatment. During this time of reduced EWM, CLP increased substantially from 1% in 2002 to 38% in 2004 (Table 1). This suggests that if EWM is effectively managed through the proposed actions, CLP management may become necessary in more than 15% of the lake to prevent recreational and ecological impairment by CLP.

(3) Research Needed: Questions remain about whether lake-‐wide control of EWM can provide long-‐term control of EWM and promote recovery of native plants in treated lakes. If a variance is approved, the CLAA and CCWD plan to collect high-‐quality data (PI surveys, mapping of surface-‐matted areas) that would be shared with the MDNR to help guide future management of EWM in Minnesota lakes.

Water Quality Protection Plans/Actions: The CCWD has drafted a comprehensive management plan for Crooked Lake that incorporates monitoring and management activities to address watershed runoff and in-‐lake water quality -‐ available online at http://www.cooncreekwd.org

Waiver of dated signature requirement for invasive aquatic plant management permits because collecting signatures would create an undue burden (M.S. 103G.615, Subp. 3a(b))

Variance approved with monitoring conditions (refer to Section 9 below)



Section 9: Required Monitoring (check all that apply)

Pre-‐treatment data collection Pre-‐treatment delineation of EWM or CLP will be provided annually with IAPM permit application to the Regional Invasive Species Specialist.

Post treatment data collection Post treatment report will be provided annually by 31 December of each year to the MNDNR Regional Invasive Species Specialist and will include treated acreage with map and GIS data, herbicide used, target concentration and amount applied.

Monitoring Annual littoral plant survey (point-‐intercept method) conducted during peak growth of native vegetation (late June through August) will be provided annually to the MNDNR Regional Invasive Species Specialist. Reliable water quality data must also be collected throughout the season. The plant survey reports and water quality data must be provided to the DNR, the lake association, and other interested parties by 31 December each year.

Evaluation The DNR, in conjunction with other interested parties, will review the plant survey(s) and water quality results annually. If plant surveys or water quality data reveal that the treatments appear to be producing results that do not meet the goals of this plan, then the approach to control may be revised at the discretion of the DNR. Table 2. Required monitoring activities.

* * Reports and maps for all monitoring activities must be delivered to the DNR by December 31 (annually) ** Approved contractor for monitoring shall not be the same contractor hired to apply herbicide

Monitoring Activity * Timing Monitored By **

1 Pre-‐treatment Delineation (EWM) Early Spring CCWD or approved contractor

2 Pre-‐treatment Delineation (CLP) Early Spring CCWD or approved contractor

3 Herbicide Application Report Immediately following herbicide application Herbicide applicator

4 Map Areas of Dense EWM and CLP Late Spring (Jun) CCWD or approved contractor

5 Whole-‐Lake Point-‐Intercept Plant Survey Mid-‐Summer (Jul-‐Sep) CCWD or approved contractor

6 Water Quality Monitoring (Secchi, TP, Chl-‐a) Twice Monthly (May-‐Sep) CCWD or approved contractor



Section 10: Signatures This Lake Vegetation Management Plan is in effect for 5 years from date of Regional Fisheries approval. If the plan is not renewed, then permits will be issued according to the standards listed in MR6280. DNR Approval: Submitted By: ___________________________ Title: __________________________________ Date: __________________________________

_______________________________________________

Regional Fisheries Manager

______________________

Date

_______________________________________________

Regional Ecological & Water Resources Manager

______________________

Date

I affirm that I am an authorized representative of Crooked Lake, Anoka County and acknowledge participation in the development and implementation of this lake vegetation management plan. ________________________________________________

Cooperator’s Signature and Title

_______________________

Date Either party may terminate participation in this plan at any time, with or without cause, upon 30 days’ written notice to the other party. If participation is terminated, permits will be issued according to standards listed MR6280.



We#have#received#and#reviewed#the#Lake#Vegetation#Management#Plan#(DNR#Short#Form)#for#Crooked#Lake.##The#plan#accurately#articulates#the#Watershed#District’s#commitment#to#adaptive#management#and#striking#a#balancebetween#controlling#aquatic#invasive#species#and#maintaining#the#diverse#and#healthy#plant#communities#essential#tosustaining#the#lake#(Section#7).##The#plan#also#accurately#describes#the#Districts#current#and#future#roles#andcommitment#to#monitoring#and#evaluating#the#annual#activities#for#lake#vegetation#management#(Section#9).#If#you#have#any#questions#please#contact#me#as#indicated#below.##I#will#follow#up#this#eLmail#with#a#signed#version#onletterhead.#Tim$KellyDistrict#AdministratorCoon#Creek#Watershed#[email protected]#

Tim Kelly <[email protected]>To: "James A. Johnson ([email protected])" <[email protected]>, "Gary Nereson ([email protected])" <[email protected]>Cc: Dawn Doering <[email protected]>Crooked Lake Vegetation Management Plan

February 27, 2013 1:47 PM

Section 11: Appendix Letter of support from Coon Creek Watershed District



Map of EWM occurrence in 2012

PLM Lake & Land Management, Inc.

Crooked Lake LVMP Shortform 3 2 2013 - freshwatersci.com · EWM!to!other!water!bodies.!The!CLAA ......

Documents

Transcript of Crooked Lake LVMP Shortform 3 2 2013 - freshwatersci.com · EWM!to!other!water!bodies.!The!CLAA ......