Lake Vegetation Management Plan
Variance Requested by Cooperator
Variance Approved (see Section VI)
Section I: Lake Information
Name: Fish Trap DOW Number: 49-0137 County: Morrison
Fisheries Area: Little Falls Surface Acres: 1,174.5 Littoral Acres: 404
Classification:
Natural Environment
Recreational Development
General Development
Cooperator(s): Fish Trap Lake Property Owner's Association, Fish Trap Lake Improvement District,
MN DNR Division of Ecological and Water Resources Invasive Species Program (ISP), MN DNR
Region 3 Fisheries-Aquatic Plant Management (APM), and MN DNR Little Falls Area Fisheries.
Section II: Water Quality and Plant Community
A. Water Quality
Total Phosphorus: 25.5 ppb mean
Secchi Disc: 1.5 meters mean
chlorophyll ‘a’: 2.2 ppb mean
Date: samples (2009)
Date: observations (1999 to 2008)
Date: samples (1999 to 2008)
Narrative (describe water quality concerns, quantify TSI): Fish Trap Lake is in the Northern
Lakes and Forests Ecoregion. Lakes in this region typically have total phosphorous levels from
14 ppb to 27 ppb, chlorophyll-a levels from 4 to 10 ppb, and Secchi disc readings from 2.4 to 4.6
meters.
Water samples were collected as part of the Minnesota Pollution Control Agency's Citizen Lake
Monitoring Program. Trophic State Index (TSI) values calculated from the averaged values for
the different water quality parameters were 50.6 TSI (Total Phosphorus), 51.9 TSI (Chlorophylla), and 41.4 TSI (Secchi disk). These values indicate that Fish Trap Lake would be considered
eutrophic. For 2010 water sample data, see information in appendix 6.
B. Plant Community:
Narrative (describe plant community, list common, rare, or other important aquatic plant species,
list plant surveys): Aquatic plants are valuable for a number of ecological and biological
functions including utilizing nutrients that would otherwise be available to algae, stabilizing lake
bottom sediments and shorelines, providing shelter for a variety of game and non-game fish and
aquatic insects, and providing food for waterfowl and other wading birds.
Based on aquatic plant surveys conducted by MN DNR Fisheries and Ecological and Water Resources
staff in June 2005 and May 2009 (Appendix 1):
*Most of the native plants were found during the June 2005 survey. A total of 24 native aquatic plant
species were recorded. Plants were found up to depths of 19 feet.
Curly-leaf pondweed or CLP (Potamogeton crispus), a non-native submerged plant, was found at 41%
frequency of occurrence in the 2005 survey and 26% frequency of occurrence in the 2009
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Lake Vegetation Management Plan
survey. Invasive species staff and DNR Little Falls Area Fisheries delineated CLP on June 26,
27, & 30, 2008, and found 80.2 acres of CLP (Appendix 3).
*Other plant species that commonly occurred were coontail (Ceratophyllum demersum) at 25%
frequency of occurrence in 2005 and 22% frequency of occurrence in 2009, and flatstem
pondweed (Potamogeton zosteriformes) at 21% frequency of occurrence in 2005 and 10%
frequency of occurrence in 2009 and muskgrass (Chara sp.) at 12% occurrence in 2005 and 10%
in 2009.
MnDNR Fisheries transect surveys were completed in 1957, 1970, 1980, 1990, and 2006. Aquatic plant
species sampled during these surveys is presented in Appendix 2.
Section III: Public Input Process (narrative):
To guide future aquatic plant control projects, a lake vegetation management plan (LVMP) was
developed in 2008 by the DNR and the Fish Trap Lake Property Owners Association. The DNR
Invasive Species Program selected Fish Trap Lake as a pilot grant lake in March of 2011. This revised
LVMP will be a coordinated effort between DNR Fisheries, DNR Ecological & Waters Resources, and
the Fish Trap Lake Property Owners Association.
Section IV: Problems to be Addressed in this Plan (narrative):
1. Ecological problems: Surface mats or dense areas of CLP may interfere with and reduce native plant
species.
2. Recreation: Areas of dense CLP may interfere with fishing, boating, and swimming. Algae blooms
may be exacerbated by decomposing CLP which may detract from the lake's aesthetics and possible use.
Section V: Goals for Management of Aquatic Plants (narrative, include a description of efforts to
protect rare features):
1. Reduce interference with recreational use on Fish Trap Lake by by reducing density and coverage of
CLP.
2. Provide long term reduction in curly-leaf pondweed while protecting water quality.
3. Protect high quality communities of native aquatic plants.
4. Increase distribution and abundance of native submerged aquatic plants.
5. Reduce peaks in concentrations of phosphorus and algal blooms presumably associated with curly
leaf pondweed die-offs.
6. Minimize potential for damage by lake wide herbicide treatments. Lake wide treatments carry the
risk of lake wide unintended negative impacts. In order to minimize this potential, lake wide treatments
will be done using specific, previously tested protocols. The result of the treatments will be carefully
monitored.
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Lake Vegetation Management Plan
7. Protect and increase emergent vegetation along the lake shore. Enforce laws associated with the
removal of aquatic plants.
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Lake Vegetation Management Plan
Section VI: Operational Treatment Plan (map marked with areas where control of plants is anticipated):
A. Lake-wide Treatment Area (>150’ and <150’ from shore)
Mechanical Control:
acres to be treated,
% of littoral area
Narrative:
Herbicide Control: Estimated at 80.2 acres in 2008 acres to be treated, 19.8 % of littoral area
Product(s): Endothall as Aquathol K or Aquathol Super K
Rate of Application: 0.75 to 1.5 ppm Aquathol K.
Timing of Application: The water temperatures should be between 50 F and 60 F and rising,
which typically occurs between late April and May. The application must occur during active
plant growth, but before turion formation begins, and before native plant species are actively
growing. Specific application dates will be affected by water temperatures and growth of curlyleaf pondweed, but must be accomplished before the water temperatures exceed 60 degrees F.
Narrative: The lake wide endothall treatment should treat all or almost all the curly-leaf
pondweed in the lake. Lake-wide treatment of CLP that is associated with the MnDNR grant
program will be within areas delineated during spring of the year of the planned treatment. No
herbicide will be applied outside of the delineated and permitted treatment areas. CLP treatment
acreage (offshore and near shore combined) is estimated to be, but not limited to, 80 acres.
Estimates of acreage will be based upon results of the annual pre-treatment delineation by
Ecological and Water Resources ISP staff. Actual acreage of each area may vary from year to
year based on success of previous year's treatments and overwinter growing conditions. If Fish
Trap Lake Property Owners Association does not receive a grant for lake-wide control of CLP,
and choose to continue with the lake-wide treatments, the responsibility of delineating the
treatment locations and determining acreages will fall on the The Fish Trap Lake Property
Owners Association. Fish Trap Lake Improvement District will prepare the APM permit
application and the application will be sent to the DNR APM office in Little Falls. Permit
issuance will be done by the DNR APM office in Little Falls. The permit will be issued
following the receipt of all necessary information. Lake wide treatments carry the risk of lake
wide unintended negative impacts. In order to minimize this potential, lake wide treatments will
be done using specific, previously tested protocols. The result of the treatments will be carefully
monitored.
Other:
acres to be treated,
% of littoral area
Narrative:
B. Individual Permit Standards (new permits)
Chemical Treatment of Submerged Vegetation: 35 feet along shore 50 feet lakeward
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Lake Vegetation Management Plan
Narrative: Any permit applications received from riparian landowners for chemical treatment of
native submersed vegetation will be considered individually. Removal of native submersed
vegetation will be limited to only that necessary to allow reasonable use, with the maximum area
being no more than 35 feet wide by 50 feet lakeward plus a 15 foot wide channel to open water
may extend from the lakeward side of the 35 by 50 foot area. No removal of sparse native
vegetation using chemicals will be permitted.
Mechanical Treatment of Emergent Vegetation: 15 feet along shore to open water
Narrative: If permit applications are received for removal of emergent or floating leaf
vegetation, they will be limited to 15 foot wide channels through dense areas of emergent or
floating leaf vegetation that prevent access to open water. In some cases where emergent
vegetation extends beyond 40 feet to 50 feet lakeward, docking over the top of the vegetation
with a permanent or floating dock will be the typical methods allowed to gain access. All
applications will be considered individually.
Other Treatment -
:
feet along shore
feet lakeward
Narrative:
Section VII: Funding [check all that apply]
Lake Association
DNR Grant
Lake Improvement District (LID)
Conservation District
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Lake Vegetation Management Plan
Section VIII: The commissioner may issue APM 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) [check all that apply]
Application of pesticides to control submerged vegetation in more than 15 percent of the
littoral area (M.R. 6280.0350, Subp. 4, A). (list justification below)
Application of pesticides to control aquatic macrophytes in natural environment lakes
established pursuant to part 6120.3000 (M.R. 6280.0250, Subp. 4, E.). (list justification
below)
Mechanical control of aquatic macrophytes in more than 50 percent of the littoral area
(M.R. 6280.0350, Subp. 3, B). (list justification below)
Other (please explain)
Justifications (identify which variance and provide the rational for all items checked above):
Treatments exceeding the 15% littoral acreage will be necessary to achieve the listed goals.
Allowing pesticide control of aquatic plants in public waters beyond 15% of the littoral acres is a
variance to M.R.6280.0350, Subp. 4, A. This variance is needed in order to increase the
effectiveness of control of curly-leaf pondweed by treating as large and contiguous an area as
possible, so that lower rates of treatment can be used. It is also necessary so that all or almost all
of the curly-leaf pondweed in the lake is treated and to prevent the formation of new turions.
Written permission for the control of curly-leaf pondweed in nearshore areas (within 150 feet of
their shoreline) must be obtained from each landowner approving of control in accordance with
Minnesota Rule 6280. Written permission must be obtained every five years or upon change of
land ownership. Signatures will be valid for a five year period (2011-2015). This is in variance
to Minnesota Rule Chapter 6280.0450, Subp.1A. The signatures must accompany the permit
application in 2011 or thereafter in cases of change in land ownership. This variance is needed
since it is likely that this will be a five year large scale control project.
Variance approved without condition(s)
Variance approved with following conditions(s):
Pretreatment data collection
Narrative: A delineation survey will be done by the MN DNR, ISP personnel, in the spring of
the year of treatment.
Also, pretreatment data based on the June 2005 and May of 2009 surveys by Perleberg and Loso (2009).
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Lake Vegetation Management Plan
Perleberg, D. and S. Loso. 2009. Aquatic vegetation of Fish Trap Lake, Morrison County, Minnesota,
2009. Minnesota Department of Natural Resources, Ecological Resources Division, 1601
Minnesota Dr., Brainerd, MN 56401. 16 pp.
Post treatment data collection
Narrative: Monitoring of the lake to document effectiveness of treatments and to provide
updated, accurate data for permit issuance is required. At a minimum, monitoring will include
pre-treatment delineation of CLP, post-treatment point-intercept survey during mid-summer
when native plants are at or near maximum abundance, bi-weekly observations of Secchi disk
transparency, and monthly water quality samples. These monitoring data will be evaluated to
determine if the CLP treatments were effective and therefore warrant continued treatment. If the
lake-wide treatment of CLP is in association with the MnDNR grant program, Ecological and
Water Resources, ISP staff will conduct the pre-treatment delineations and post-treatment pointintercept surveys and Fish Trap Lake Property Owners Association will be responsible for biweekly observations of Secchi disk tansparency and collection of monthly water quality samples
for determination of total phosporous and chlorophyll-a levels. If Fish Trap Lake Property
Owners Association does not receive a grant for lake-wide control of CLP at some point during
the period of this plan, and chooses to continue with the lake-wide treatments, the responsibility
of completing the above required monitoring work in an acceptable manner will fall entirely on
the Fish Trap Lake Property Owners Association. Monitoring protocols are outlined in
Appendix 4 and GPS coordinates that should be used for the point-intercept plant surveys are
included in Appendix 5. If a private consultant is contracted to do the point intercept survey, the
same consultant (or someone affiliated with that consultant) cannot do the commercial herbicide
application. Monitoring data shall be submitted to the MnDNR's IS Program in Brainerd prior to
the end of that treatment year. Results must be compiled and submitted in a manner that is
readily reviewable by ISP staff. These data must be received before a permit will be issued for
the following year as APM staff will consult with ISP staff before permit issuance. The results
of the pre-treatment delineation detailing proposed treatment areas for that season must either
accompany the permit application sent to the Little Falls APM Office or follow the application,
as long as it is received prior to permit issuance and treatment. The MnDNR will not issue a
permit before the results of the pre-treatment delineation of CLP are received. The above
monitoring will be done to determine if goals are being met and if treatment protocols should be
continued in subsequent years.
Evaluation
Narrative: Lake-wide teatment of CLP may not be permitted if results of monitoring indicate
that the treatment is doing more harm than good. In the event that treatments are found to cause
significant negative impacts to the native plant community, water quality, fish community or any
combination in Fish Trap Lake, the MnDNR will work with the Fish Trap Lake Property Owners
Association to develop an alternate treatment plan.
Other:
Narrative:
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Lake Vegetation Management Plan
Section IX: Signatures
This Lake Vegetation Management Plan is in effect for
approval.
years from date of last signature of
DNR Approval
Submitted By: ___________________________
Title: __________________________________
Date: __________________________________
_________________________________________
Area Fisheries Supervisor
______________________________________
Date
_________________________________________
Regional Fisheries Approval
______________________________________
Date
_________________________________________
Regional Ecological Resources Approval
______________________________________
Date
I affirm that I am an authorized representative of Fish Trap Lake Property Owners Association and
acknowledge our 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.
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