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Aquatic Vegetation Management Plan

2017 Update

Hudson Lake, LaPorte County, Indiana

Prepared for:

The Hudson Lake Conservation Association 7365 E. Hudson Pointe Lane

New Carlisle, IN 46552

March 1, 2018

Prepared by:

Aquatic Weed Control P. O. Box 325

Syracuse, IN 46567

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Executive Summary Hudson Lake, located in LaPorte County, Indiana has 430 surface acres with a maximum depth of 39 feet (Indiana Clean Lakes Program, 2010). Eurasian watermilfoil (Myriophyllum spicatum), spiny naiad (Najas marina), starry stonewort (Nitellopsis obtusa), and curly-leaf pondweed (Potamogeton crispus) are exotic submersed plant/algae species present in Hudson Lake. Common reed (Phragmites australis) is also an invasive emergent plant species present in the lake. Eurasian watermilfoil (EWM) and Phragmites have reached nuisance quantities in many areas of the lake. The following report summarizes Eurasian watermilfoil (EWM), starry stonewort (SSW) and Phragmites control practices implemented on Hudson Lake through the Lake and River Enhancement Program (LARE). It also outlines future exotic plant management options. The Hudson Lake Conservation Association has been active in controlling EWM both privately and with assistance from LARE since 2007. These treatments have utilized 2,4-D based herbicides with treatment acreages varying from 4.2 to 33.64 acres. In 2017, LARE funding was granted for EWM, SSW, and Phragmites treatments on Hudson Lake as well as updating the Aquatic Vegetation Management Plan (AVMP). Aquatic Weed Control, Inc. was contracted to provide surveys, plans, and treatment services. Two EWM treatments occurred on the lake in 2017. On May 30, two areas of Eurasian watermilfoil, totaling 6.54 acres, were treated on Hudson Lake. Area 1 consisted of 5.66 acres on the west side of the lake and was treated with 2,4-D at 2.0 ppm. Area 2 was located on the east side of the large island, and consisted of 0.88 acres. This area was designated as the test plot for control with granular Triclopyr at 1.5 ppm. On August 7, 2.7 acres (Area 1) of Starry stonewort were treated with Clipper at a rate of 200 ppb. Lake water pH was evaluated and documented before the treatment, so as to be consistent with the herbicide label instructions. The final three treatment applications were conducted on August 25. Two areas of EWM totaling 2.66 acres were treated with 2,4-D at 2.0 ppm. One area of Phragmites, totaling 0.73 acres, was treated with a 1% solution of Glyphosate and Imazapyr. Finally, a second application was made for control of SSW (Area 2). This area consisted of 2.48 acres and was treated with Clipper at 200 ppb. A quantitative Tier II vegetation survey was conducted on Hudson Lake on August 7, 2017. In this survey, EWM was collected at 6.3% for all depth contours of the 80 sample locations. The established target EWM frequency objective of 10% or less was achieved for this season. Notably, for the first time during a Tier II survey of Hudson Lake, starry stonewort was collected at 1.3%. Fifteen species of native plants were found during the August 2017 Tier II survey, and native plant diversity was 0.86. The established native species richness and native plant diversity objectives are 16 species, with a diversity of 0.86. For 2018, all areas of EWM will be treated with liquid 2, 4-D herbicide at a rate of 2.0 ppm. It is recommended that funding be available to treat approximately 30 acres of EWM with liquid 2,4-D. The 2017 test plot to control EWM with granular Triclopyr will be abandoned during the 2018 season. Lastly, it is recommended that approximately 15 acres of the newly identified SSW be treated with Cutrine Ultra algeacide. It is important to note that the EWM/SSW treatments will not eradicate these species in Hudson Lake. The treatments should help native plants to compete with EWM/SSW on an annual basis, while providing greater recreational access to the lake.

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Table of Contents Executive Summary ........................................................................................................................ 2

Problem Statement .......................................................................................................................... 4

Aquatic Vegetation Management History ...................................................................................... 4

2017 Vegetation Treatments ........................................................................................................... 5

Tier II Survey Results ................................................................................................................... 12

Water Clarity and Water Quality .................................................................................................. 21

Action Plan.................................................................................................................................... 23

2018 Project Budget ...................................................................................................................... 24

Public Involvement ....................................................................................................................... 25

References Cited ........................................................................................................................... 27

Appendix ....................................................................................................................................... 28

Common and Scientific Names of Aquatic Plants in Hudson Lake ............................................ 28

Data Sheet and GPS Coordinates .................................................................................................. 29

2018 LARE Treatment Permit ...................................................................................................... 31

List of Tables Table 1: Hudson Lake EWM Treatment History .................................................................................................................. 4 Table 2: Hudson Lake Phragmites Treatment History.......................................................................................................... 5 Table 3: Hudson Lake SSW Treatment History ................................................................................................................... 5 Table 4: Hudson Lake 2017 Treatment Details for EWM .................................................................................................... 6 Table 5: Hudson Lake 2017 Treatment Details for SSW ..................................................................................................... 6 Table 6: Hudson Lake 2017 Treatment Details for Phragmites ............................................................................................ 6 Table 7: Hudson Lake Summer 2017 Tier II Data Analysis ............................................................................................... 16 Table 8: Hudson Lake Multi-Year Tier II Data Presentation ............................................................................................. 18 Table 9: Hudson Lake Secchi Depth History ..................................................................................................................... 21 List of Figures Figure 1: Hudson Lake May 30, 2017, EWM Treatment Areas ........................................................................................... 7 Figure 2: Hudson Lake August 25, 2017, EWM Treatment Areas ....................................................................................... 8 Figure 3: Hudson Lake August 7, 2017, SSW Treatment Area ............................................................................................ 9 Figure 4: Hudson Lake August 25, 2017, SSW Treatment Area ........................................................................................ 10 Figure 5: Hudson Lake August 25, 2017, Phragmites Treatment Area .............................................................................. 11 Figure 6: Hudson Lake - Untreated Phragmites Area 2017 ................................................................................................ 11 Figure 7: Hudson Lake Tier II Sample Locations .............................................................................................................. 12 Figure 8: Hudson Lake Summer 2017 Tier II EWM Locations ......................................................................................... 13 Figure 9: Hudson Lake Summer 2017 Tier II Spiny Naiad Locations ............................................................................... 14 Figure 10: Hudson Lake Summer 2017 Tier II Starry Stonewort Location ........................................................................ 15 Figure 11: Hudson Lake 2017 Dissolved Oxygen Profile .................................................................................................. 22 Figure 12: Hudson Lake 2017 Temperature Profile ........................................................................................................... 22 Figure 13: Hudson Lake Public Meeting Survey Data ...................................................................................................... 26

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Problem Statement Eurasian watermilfoil, starry stonewort, and Phragmites are affecting the use of Hudson Lake in several areas. EWM and SSW form dense mats in shallow areas, which can inhibit fishing, swimming, and boating. Dense infestations of these species can also prevent the growth of beneficial native plant species, which often provide less recreational interference and more desirable fish habitat. In some areas Phragmites continues to out-compete some beneficial plants as it increases along the shoreline. Curly-leaf pondweed and spiny naiad are two other exotic plant species found in the lake, but they do not appear to be causing any significant impairment. Objectives: The following specific, quantifiable objectives are recommended to evaluate the success of management activities. These objectives were previously established by Scribailo and Alix in the 2013 AVMP update for Hudson Lake. The fourth objective was included during the 2016 season and the fifth objective was included during the 2017 AVMP update.

A frequency of EWM at less than 10% of the points in a post treatment Tier II survey.

A EWM rake score of no more than 1 for any sampling site where EWM is recorded in a post-treatment Tier II survey.

Maintain a native species richness of at least 16 and a native species diversity index value of at least 0.86 in a Tier II survey.

Maintain a minimum coverage of 62%, plant(s) collected at 50 of the 80 sampling sites.

Maintain SSW abundance to a quantity that does not hinder lake use activities while using 50/50 cost share funding for herbicide applications.

Treating EWM and SSW is not likely to eradicate it from Hudson Lake. However, if these objectives are met each year, the indication would be that EWM is being controlled effectively on a seasonal basis, without causing significant damage to the native plant community. Aquatic Vegetation Management History Tables 1, 2, and 3 show treatment history summaries for EWM, Phragmites, and SSW at Hudson Lake. The Hudson Lake Association has been very committed to treating EWM infestations with the help of the LARE program. The acreages of EWM treatments in Hudson Lake vary from year to year based on EWM abundance. Table 1: Hudson Lake EWM Treatment History

Year Acreage Herbicide Rate 2007* 25 DMA-4 2.0 ppm 2008* 20 DMA-4 2.0 ppm 2009* 12 Navigate 2.0 ppm 2010 4.2 DMA-4 2.0 ppm 2011 10 DMA-4 2.0 ppm 2012* 8.67 DMA-4/Navigate 2.0 ppm 2013* 10.6 DMA-4 2.0 ppm

2014* 16.2 DMA-4 2.0 ppm

2015* 33.64 DMA-4 2.0 ppm

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2016* 29.17 DMA-4 2.0 ppm 2017* 8.32 DMA-4 2.0 ppm 2017* 0.88 Renovate OTF / Triclopyr 1.5 ppm

*LARE Funded Table 2: Hudson Lake Phragmites Treatment History

Year Acreage Herbicide Rate 2015* 8.33 Glyphosate/Imazapyr 1% Solution 2016 No Treatments 2017* 0.73 Glyphosate/Imazapyr 1% Solution

*LARE Funded Table 3: Hudson Lake SSW Treatment History

Year Acreage Herbicide Rate 2016* 1.02 Clipper/Copper Sulfate 200 ppb/1.0 ppm 2017** 5.18 Clipper (Flumioxazin) 200 ppb

*Great Lakes Restoration Initiative (GLRI) Funded **LARE Funded 2017 Vegetation Treatments Two EWM herbicide treatments were performed on Hudson Lake during the 2017 season. On May 24, AWC staff conducted a visual survey to identify areas of severe EWM infestation. This survey identified a total of 6.54 acres; Figure 1 shows the dense EWM beds. On May 30, AWC treated 5.66 acres (Area 1) with DMA-4 herbicide at a rate of 2.0 parts per million (ppm) and 0.88 acres (Area 2) with Renovate OTF at a rate of 1.5 ppm. Area 2 was selected as the test plot area based on the size of the area and the depth at which the EWM was growing. A second visual survey was completed on August 7 during the Tier II survey, during which AWC recorded 2.66 acres of EWM growth. A map (Figure 2) was then submitted to the IDNR for herbicide treatment approval. On August 25, the 2.66 acres of EWM infestation were treated with DMA-4 herbicide at a rate of 2.0 ppm. On June 27, 2.7 acres of SSW were identified and proposed for treatment. On August 7, the 2.7 acres (Area 1) of SSW was treated with Clipper at a rate of 200 ppb. Figure 3 displays the treatment map. During the Tier II survey, AWC staff identified an additional 2.48 acres (Area 2) of SSW. This area was also treated with Clipper at 200 ppb and Figure 4 displays the treatment map. Lake water pH was evaluated and documented before the treatment, so as to be consistent with the herbicide label instructions. During the first Clipper application the lake water pH was recorded at 7.65 and during the second Clipper application the lake water pH was 7.58. A buffer agent was added during mixing to reduce pH below 7. According to the Clipper herbicide label, there is greater efficacy to control vegetation when Clipper is applied to waterbodies with a pH value less than 8.5. One area of Phragmites (Figure 5), totaling 0.73 acre, was treated with a 1% solution of Glyphosate and Imazapyr on August 25. During the 2017 season there was a second area of Phragmites that consisted of 0.51 acres. However, there was not a route to access the area and be able to adequately apply the herbicide. Therefore, no herbicide applications were made to this area. Figure 6 displays the location of this area. Average depths and treatment details for each area and species treated in 2017 are described in Tables 4, 5, and 6.

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Table 4: Hudson Lake 2017 Treatment Details for EWM

May 30, 2017 Treatment Application

Area Acres Avg. Depth Herbicide Rate

1 5.66 4 feet DMA-4 2.0 ppm 2 0.88 5 feet Renovate OTF 1.5 ppm

August 25, 2017 Treatment Application 1 1.01 6 feet DMA-4 2.0 ppm 2 1.65 6 feet DMA-4 2.0 ppm

Table 5: Hudson Lake 2017 Treatment Details for SSW

August 7, 2017 Treatment Application

Area Acres Avg. Depth Herbicide Rate

Area 1 2.7 3 feet Clipper 200 ppb August 25, 2017 Treatment Application

Area 2 2.48 4 feet Clipper 200 ppb Table 6: Hudson Lake 2017 Treatment Details for Phragmites

August 25, 2017 Treatment Application Area Acres Avg. Depth Herbicide Rate Area 1 0.73 N/A Glyphosate/Imazapyr 1% Solution Area A – Untreated Phragmites 0.51 acres - Inaccessible

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Figure 1: Hudson Lake May 30, 2017, EWM Treatment Areas

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Figure 2: Hudson Lake August 25, 2017, EWM Treatment Areas

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Figure 3: Hudson Lake August 7, 2017, SSW Treatment Area

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Figure 4: Hudson Lake August 25, 2017, SSW Treatment Area

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Figure 5: Hudson Lake August 25, 2017, Phragmites Treatment Area

Figure 6: Hudson Lake - Untreated Phragmites Area 2017

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Tier II Survey Results Aquatic plant sampling methods used for surveys on Hudson Lake are outlined in the Tier II Aquatic Vegetation Survey Protocol (IDNR, 2014). The same sample locations that were used in the previous year were again used in the August 7, 2017 Tier II survey. Common and scientific names mentioned in the Tier II results are consistent with those mentioned in the original AVMP in 2008, and are also listed in the appendix to this report. Figure 7 shows rake sample locations for the Hudson Lake Tier II survey. Eighty sample sites are divided between the 5-foot contours of the littoral zone and spaced randomly throughout the lake. The objective for assessing the current management plan was partially achieved with a native species diversity of 0.86, which is equivalent with the objective parameter. However, the amount of native plants collected (15 in 2017 survey) during the 2017 survey did not meet the minimum amount of native plants (16) collected to satisfy this objective goal. Another objective for this plan was achieved, with 65% of the sites having plants. Refer to page 4 of this report for the outlined management objectives. Figure 7: Hudson Lake Tier II Sample Locations

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Exotic Plant Distribution Eurasian Watermilfoil Abundance The summer 2017, Tier II survey was conducted on August 7, and found EWM present at 6.3% of the eighty sample locations for all depth contours. This is a decrease from 13.8% when compared to the 2016 survey data. With EWM at 6.3% in 2017, the target objective of EWM frequency of 10.0% or less was achieved. However, a EWM rake score of no more than 1 for any sampling waypoint where EWM is recorded in a post-treatment Tier II survey was not achieved during this season. Figure 8 shows all Tier II sample locations where EWM was collected. EWM sites are shown as red dots with the EWM abundance score listed beside each dot. Figure 8: Hudson Lake Summer 2017 Tier II EWM Locations

Curly-Leaf Pondweed Abundance Curly-leaf pondweed (CLP) is present in Hudson Lake, but does not generally grow to nuisance quantities. CLP was not collected in the August 2017, Tier II survey. Summer surveys do not usually represent CLP populations well because CLP usually begins to die naturally as water temperatures reach 70 to 75 degrees Fahrenheit. The 2013 summer Tier II survey conducted by Aquatic Restoration Systems was the most recent survey to find CLP in Hudson Lake. This survey found CLP at a frequency of 6.0%. The visual survey conducted by Aquatic Weed Control Inc. on May 24, 2017 did not find CLP to be causing significant impairment in Hudson Lake.

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Spiny Naiad Abundance Spiny naiad is another exotic plant species present in Hudson Lake. Figure 9 shows where spiny naiad was collected during the summer Tier II survey. In past Tier II surveys, the site frequency has varied from 1.2% to 10.7%. On August 7, 2017, spiny naiad frequency for all depth contours was 1.3%. Based on past survey data it does not appear that spiny naiad is significantly increasing in Hudson Lake, nor does it appear to be causing any impairment of the lake. Figure 9: Hudson Lake Summer 2017 Tier II Spiny Naiad Locations

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Starry Stonewort Abundance Notably, for the first time during a Tier II survey of Hudson Lake, Starry stonewort was collected at 1.3% for all depth contours. Figure 10 shows where Starry stonewort was collected during the summer Tier II survey. It will be paramount to aggressively treat any identified Starry stonewort with herbicides to keep this invasive vegetation from expanding in the lake. Figure 10: Hudson Lake Summer 2017 Tier II Starry Stonewort Location

Results from the August 7, 2017 Tier II survey on Hudson Lake are summarized in Table 7. Site frequency, dominance, diversity, and other metrics are shown for the entire survey (all depths) and also for each 5 foot depth contour where plants were present. In this survey, no plants were found deeper than 17 feet.

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Table 7: Hudson Lake Summer 2017 Tier II Data Analysis

County: LaPorte Secchi (ft): 10.5 Mean species/site: 1.89Date: 8/7/2017 Sites with plants: 52 SE Mean species/site: 0.20

Littoral Depth (ft): 17.0 Sites with native plants: 52 Mean native species/site: 1.80Littoral Sites: 61 Number of species: 18 SE Mean natives/site: 0.20

Total Sites: 80 Number of native species: 15 Species diversity: 0.87Maximum species/site: 7 Native species diversity: 0.86

All DepthsSpecies 0 1 3 5Chara 46.3 53.8 8.8 18.8 18.8 31.8Eel grass 32.5 67.5 22.5 10.0 0.0 10.5Common naiad 25.0 75.0 16.3 7.5 1.3 9.0Common bladderwort 15.0 85.0 7.5 5.0 2.5 7.0Illinois pondweed 11.3 88.8 10.0 1.3 0.0 2.8Coontail 10.0 90.0 6.3 2.5 1.3 4.0Flat-stemmed pondweed 10.0 90.0 6.3 3.8 0.0 3.5Eurasian watermilfoil 6.3 93.8 5.0 1.3 0.0 1.8Sago pondweed 6.3 93.8 2.5 2.5 1.3 3.3Purple bladderwort 5.0 95.0 5.0 0.0 0.0 1.0Small pondweed 5.0 95.0 5.0 0.0 0.0 1.0Variable watermilfoil 3.8 96.3 2.5 1.3 0.0 1.3American pondweed 2.5 97.5 1.3 1.3 0.0 1.0Canada waterweed 2.5 97.5 2.5 0.0 0.0 0.5Varible pondweed 2.5 97.5 2.5 0.0 0.0 0.5Whorled watermilfoil 2.5 97.5 1.3 0.0 1.3 1.5Spiny naiad 1.3 98.8 1.3 0.0 0.0 0.3Starry stonewort 1.3 98.8 1.3 0.0 0.0 0.3




Depths: 0 to 5 ftSpecies 0 1 3 5Chara 73.7 26.3 15.8 42.1 15.8 44.2Common naiad 42.1 57.9 31.6 5.3 5.3 14.7Eel grass 31.6 68.4 21.1 10.5 0.0 10.5Illinois pondweed 31.6 68.4 26.3 5.3 0.0 8.4Common bladderwort 21.1 78.9 10.5 5.3 5.3 10.5Flat-stemmed pondweed 15.8 84.2 10.5 5.3 0.0 5.3American pondweed 10.5 89.5 5.3 5.3 0.0 4.2Coontail 10.5 89.5 10.5 0.0 0.0 2.1Purple bladderwort 10.5 89.5 10.5 0.0 0.0 2.1Varible pondweed 10.5 89.5 10.5 0.0 0.0 2.1Eurasian watermilfoil 5.3 94.7 5.3 0.0 0.0 1.1Sago pondweed 5.3 94.7 5.3 0.0 0.0 1.1Small pondweed 5.3 94.7 5.3 0.0 0.0 1.1Starry stonewort 5.3 94.7 5.3 0.0 0.0 1.1Variable watermilfoil 5.3 94.7 5.3 0.0 0.0 1.1Whorled watermilfoil 5.3 94.7 5.3 0.0 0.0 1.1

Frequency of Occurrence

Rake score frequency per species Plant Dominance



Occurrence and Abundance of Submersed Aquatic Plants in Hudson Lake.


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Table 7 continued




Depths: 5 to 10 ftSpecies 0 1 3 5Chara 83.3 16.7 5.6 16.7 61.1 72.2Eel grass 55.6 44.4 38.9 16.7 0.0 17.8Common bladderwort 33.3 66.7 16.7 16.7 0.0 13.3Flat-stemmed pondweed 27.8 72.2 16.7 11.1 0.0 10.0Common naiad 22.2 77.8 11.1 11.1 0.0 8.9Eurasian watermilfoil 16.7 83.3 11.1 5.6 0.0 5.6Illinois pondweed 16.7 83.3 16.7 0.0 0.0 3.3Canada waterweed 11.1 88.9 11.1 0.0 0.0 2.2Coontail 11.1 88.9 11.1 0.0 0.0 2.2Purple bladderwort 5.6 94.4 5.6 0.0 0.0 1.1Sago pondweed 5.6 94.4 5.6 0.0 0.0 1.1Small pondweed 5.6 94.4 5.6 0.0 0.0 1.1Variable watermilfoil 5.6 94.4 0.0 5.6 0.0 3.3Whorled watermilfoil 5.6 94.4 0.0 0.0 5.6 5.6




Depths: 10 to 15 ftSpecies 0 1 3 5Eel grass 58.8 41.2 41.2 17.6 0.0 18.8Chara 47.1 52.9 17.6 23.5 5.9 23.5Common naiad 41.2 58.8 23.5 17.6 0.0 15.3Sago pondweed 17.6 82.4 0.0 11.8 5.9 12.9Common bladderwort 11.8 88.2 5.9 0.0 5.9 7.1Coontail 11.8 88.2 0.0 5.9 5.9 9.4Small pondweed 11.8 88.2 11.8 0.0 0.0 2.4Eurasian watermilfoil 5.9 94.1 5.9 0.0 0.0 1.2Purple bladderwort 5.9 94.1 5.9 0.0 0.0 1.2Spiny naiad 5.9 94.1 5.9 0.0 0.0 1.2Variable watermilfoil 5.9 94.1 5.9 0.0 0.0 1.2




Depths: 15 to 20 ftSpecies 0 1 3 5Coontail 12.5 87.5 6.3 6.3 0.0 5.0Common naiad 6.3 93.8 6.3 0.0 0.0 1.3










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Multi-Year Data Presentation Data from recent Tier II surveys of Hudson Lake is summarized in Table 8. This summarization helps to track trends in species abundance and frequency, along with overall plant metrics. These help to better represent the overall state of the plant community. Data from surveys prior to 2014 was provided by Aquatic Restoration Systems. Table 8: Hudson Lake Multi-Year Tier II Data Presentation

Date: 6/21/2007 8/17/2007 8/14/2008 8/21/2009 8/8/2012 8/12/2013 8/12/2014 8/13/2015 8/1/2016 8/26/2016 8/7/2017Total Sites: 84 84 84 84 84 84 80 80 80 80 80Secchi (ft): 15.1 14.3 13.0 12.0 12.0 13.5 12.1 12.8 11.0 12.5 10.5Number of Species: 17 18 19 18 14 20 17 16 19 16 18Number of Native Species: 14 15 16 16 12 17 15 14 17 14 15Sites with Plants 71 70 71 63 46 41 54 53 58 55 52Sites with Native Plants 32 36 54 59 46 39 52 52 58 55 52Maximum Plant Depth (ft) 22.0 23.0 24.0 23.0 21.1 14.2 17.0 19.0 21.5 19.0 17.0Species Diversity: 0.90 0.91 0.91 0.89 0.85 0.90 0.88 0.84 0.88 0.88 0.87Native Species Diversity: 0.88 0.90 0.90 0.88 0.83 0.87 0.86 0.81 0.87 0.86 0.86Mean Native Species/Site: 2.4 2.5 2.4 1.9 1.2 1.4 1.4 1.36 1.94 1.81 1.80Surveying Organization AQRS AQRS AQRS AQRS AQRS AQRS AWC AWC DNR AWC AWC

Water marigold 0.0 0.0 2.4 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0Coontail 33.3 32.1 36.9 31.0 15.5 3.6 17.5 11.3 20.0 13.8 10.0Chara 28.6 39.3 32.1 26.0 33.3 32.1 33.8 42.5 47.5 45.0 46.3Canada waterweed 0.0 0.0 0.0 1.2 0.0 1.2 1.3 1.3 1.3 1.3 2.5Water stargrass 8.3 11.9 2.4 2.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eurasian watermilfoil 48.5 38.1 28.6 8.3 9.5 16.7 12.5 5.0 8.8 13.8 6.3Whorled watermilfoil 0.0 0.0 0.0 0.0 0.0 1.2 2.5 3.8 2.5 0.0 2.5Northern watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0Variable watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.8Common naiad 3.6 17.9 16.7 22.6 11.9 7.1 12.5 8.8 21.3 17.5 25.0Southern naiad 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 1.3 0.0 0.0Spiny naiad 1.2 4.8 6.0 10.7 3.6 2.4 5.0 6.3 1.3 8.8 1.3Nitella 4.8 7.2 3.6 6.0 0.0 3.6 0.0 0.0 1.3 1.3 0.0Large-leaved pondweed 7.1 6.0 10.7 3.6 1.2 1.2 1.3 0.0 0.0 0.0 0.0Curly-leaf pondweed 14.3 3.6 1.2 0.0 0.0 6.0 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 23.8 3.6 21.4 1.2 0.0 6.0 1.3 0.0 5.0 0.0 0.0Variable pondweed 2.4 9.5 4.8 6.0 0.0 0.0 0.0 0.0 15.0 0.0 2.5Illinois pondweed 10.7 14.3 11.9 0.0 4.8 3.6 20.0 12.5 3.8 25.0 11.3Floating-leaf pondweed 0.0 0.0 1.2 3.6 1.2 3.6 0.0 0.0 3.8 0.0 0.0American pondweed 0.0 0.0 0.0 0.0 0.0 0.0 5.0 1.3 0.0 3.8 2.5Cabomba 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0Small pondweed 0.0 0.0 0.0 0.0 0.0 6.0 0.0 3.8 3.8 2.5 5.0Flat-stemmed pondweed 13.1 10.7 6.0 1.2 2.4 2.4 3.8 1.3 0.0 1.3 10.0Sago pondweed 9.5 8.3 13.1 9.5 4.8 11.9 3.8 1.3 12.5 15.0 6.3Humped bladderwort 0.0 1.2 0.0 1.2 1.2 1.2 0.0 0.0 6.3 0.0 0.0Common bladderwort 2.4 4.8 11.9 10.7 8.3 9.5 8.8 11.3 10.0 10.0 15.0Purple bladderwort 4.8 2.4 7.1 0.0 1.2 8.3 5.0 2.5 0.0 11.3 5.0Eel grass 33.3 34.5 31.0 38.1 22.6 10.7 22.5 33.8 33.8 32.5 32.5Fern pondweed 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.0 0.0 0.0Starry stonewort 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3Filamentous algae 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.5 0.0 0.0

Hudson Lake Multi-Year Data Presentation

Species Frequency of Occurrence - All Depths

19

Table 8 continued

Water marigold 0.0 0.0 4.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Coontail 8.7 8.7 19.0 12.5 0.0 0.0 26.3 15.8 15.8 26.3 10.5Chara 69.6 82.6 71.4 0.0 87.5 73.3 57.9 84.2 84.2 73.7 73.7Canadian waterweed 0.0 0.0 0.0 0.0 0.0 6.7 5.3 5.3 5.3 5.3 0.0Eurasian watermilfoil 39.1 26.1 19.0 0.0 37.5 33.3 15.8 15.8 10.5 26.3 5.3Whorled watermilfoil 0.0 0.0 0.0 0.0 0.0 6.7 5.3 15.8 5.3 0.0 5.3Northern watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.5 0.0 0.0Variable watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.3Common naiad 4.3 26.1 23.8 12.5 25.0 20.0 26.3 10.5 36.8 36.8 42.1Spiny naiad 4.3 0.0 19.0 37.5 0.0 13.3 0.0 10.5 0.0 5.3 0.0Nitella 0.0 8.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Large-leaved pondweed 4.3 17.4 9.5 0.0 0.0 6.7 0.0 0.0 0.0 0.0 0.0Floating-leaf pondweed 0.0 0.0 4.8 12.5 12.5 20.0 0.0 0.0 15.8 0.0 0.0Curly-leaf pondweed 0.0 0.0 0.0 0.0 0.0 6.7 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 8.7 4.3 0.0 0.0 0.0 0.0 0.0 0.0 5.3 0.0 0.0Variable pondweed 8.7 30.4 14.3 12.5 0.0 0.0 0.0 0.0 47.4 0.0 10.5Illinois pondweed 21.7 13.0 19.9 0.0 25.0 0.0 57.9 26.3 15.8 52.6 31.6American pondweed 0.0 0.0 0.0 0.0 0.0 0.0 10.5 0.0 0.0 10.5 10.5Cabomba 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.3 0.0Small pondweed 0.0 0.0 0.0 0.0 0.0 6.7 0.0 0.0 0.0 5.3 5.3Flat-stemmed pondweed 4.3 4.3 0.0 0.0 12.5 6.7 5.3 0.0 0.0 5.3 15.8Sago pondweed 26.1 21.7 28.6 12.5 12.5 20.0 5.3 5.3 21.1 15.8 5.3Humped bladderwort 0.0 4.3 0.0 12.5 0.0 0.0 0.0 0.0 10.5 0.0 0.0Common bladderwort 8.7 17.4 38.1 50.0 37.5 40.0 26.3 26.3 15.8 21.1 21.1Purple bladderwort 17.4 7.4 23.8 0.0 0.0 20.0 15.8 10.5 0.0 31.6 10.5Eel grass 21.7 17.4 23.8 0.0 75.0 6.7 31.6 47.4 36.8 31.6 31.6Starry stonewort 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.3

Water-marigold 0.0 0.0 5.9 4.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0Coontail 11.1 16.7 0.0 4.5 13.6 0.0 5.6 5.6 16.7 0.0 11.1Chara 38.9 66.7 58.8 54.5 72.7 66.7 72.2 66.7 94.4 88.9 83.3Canadian waterweed 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.1Water stargrass 5.6 11.1 0.0 18.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eurasian watermilfoil 55.6 61.1 47.1 0.0 9.1 38.9 33.3 5.6 22.2 22.2 16.7Northern watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.6 0.0 0.0Whorled watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.6 0.0 5.6Variable watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.6Common naiad 11.1 44.4 41.2 54.5 0.0 11.1 16.7 16.7 22.2 22.2 22.2Southern naiad 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.6 0.0 0.0 0.0Spiny naiad 0.0 16.7 5.9 18.2 9.1 0.0 16.7 0.0 5.6 16.7 0.0Large-leaved pondweed 27.8 5.6 35.3 9.1 9.5 0.0 0.0 0.0 0.0 0.0 0.0Curly-leaf pondweed 5.6 5.6 0.0 0.0 0.0 5.6 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 61.1 5.6 35.3 0.0 0.0 27.8 0.0 0.0 11.1 0.0 0.0Variable pondweed 0.0 5.6 5.9 18.2 0.0 0.0 0.0 0.0 16.7 0.0 0.0Illinois pondweed 22.2 44.4 29.4 0.0 9.1 16.7 27.8 27.8 0.0 50.0 16.7American pondweed 0.0 0.0 0.0 0.0 0.0 0.0 11.1 5.6 0.0 5.6 0.0Floating-leaf pondweed 0.0 0.0 0.0 9.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0Small pondweed 0.0 0.0 0.0 0.0 0.0 11.1 0.0 0.0 0.0 0.0 5.6Flat-stemmed pondweed 22.2 11.1 5.9 0.0 4.5 5.6 11.1 5.6 0.0 0.0 27.8Sago pondweed 11.1 11.1 23.5 22.7 9.1 33.3 0.0 0.0 27.8 22.2 5.6Humped bladderwort 0.0 0.0 0.0 0.0 4.5 5.6 0.0 0.0 16.7 0.0 0.0Common bladderwort 0.0 0.0 5.9 22.7 18.2 11.1 11.1 11.1 27.8 16.7 33.3Purple bladderwort 0.0 0.0 0.0 0.0 4.5 11.1 0.0 0.0 0.0 11.1 5.6Eel grass 72.2 83.3 76.5 59.1 27.3 33.3 38.9 44.4 61.1 50.0 55.6Fern pondweed 0.0 0.0 0.0 0.0 0.0 0.0 5.6 0.0 0.0 0.0 0.0

Species Frequency of Occurrence - 0 to 5 ft


20

Table 8 continued

Coontail 58.8 48.3 55.6 50.0 25.0 17.6 23.5 17.6 29.4 17.6 11.8Chara 0.0 6.3 11.1 50.0 25.0 23.5 17.6 35.3 29.4 35.3 47.1Water stargrass 5.9 31.3 5.6 12.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eurasian watermilfoil 64.7 75.0 50.0 18.8 12.5 11.8 5.9 0.0 5.9 11.8 5.9Northern watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.9 0.0 0.0Variable watermilfoil 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.9Common naiad 17.6 6.3 11.1 31.3 18.8 5.9 11.8 11.8 35.3 17.6 41.2Spiny naiad 0.0 6.3 0.0 12.5 6.3 0.0 5.9 17.6 0.0 17.6 5.9Southern naiad 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.9 0.0 0.0Nitella 0.0 6.3 16.7 12.5 0.0 17.6 0.0 0.0 5.9 5.9 0.0Large-leaved pondweed 0.0 0.0 5.6 6.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0Curly-leaf pondweed 47.1 12.5 5.6 0.0 0.0 17.6 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 35.3 6.3 61.1 6.3 0.0 0.0 5.9 0.0 5.9 0.0 0.0Illinois pondweed 0.0 6.3 5.6 0.0 0.0 0.0 0.0 0.0 0.0 5.9 0.0Small pondweed 0.0 0.0 0.0 0.0 0.0 11.8 0.0 11.8 11.8 5.9 11.8Flat-stem pondweed 35.3 18.8 21.2 6.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0Sago pondweed 0.0 0.0 5.6 12.5 6.3 5.9 5.9 0.0 5.9 29.4 17.6Common bladderwort 0.0 0.0 5.6 0.0 0.0 0.0 0.0 11.8 0.0 5.9 11.8Purple bladderwort 0.0 0.0 5.6 0.0 0.0 11.8 5.9 0.0 0.0 5.9 5.9Eel grass 52.9 50.0 38.9 75.0 43.8 11.8 23.5 58.8 52.9 64.7 58.8Filamentous algae 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.8 0.0 0.0

Coontail 62.5 80.0 66.7 58.3 20.8 0.0 25.0 12.5 25.0 18.8 12.5Chara 6.3 6.7 0.0 4.2 4.2 0.0 0.0 0.0 0.0 0.0 0.0Canada waterweed 0.0 0.0 0.0 4.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0Water star grass 31.3 20.0 6.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eurasian watermilfoil 25.0 20.0 13.3 0.0 4.2 0.0 0.0 0.0 0.0 0.0 0.0Common naiad 0.0 0.0 0.0 4.2 4.2 0.0 0.0 0.0 0.0 0.0 6.3Nitella 6.3 13.3 0.0 12.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0Curly-leaf pondweed 18.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 6.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Small pondweed 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.3 6.3 0.0 0.0Flat-stemmed pondweed 0.0 20.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eelgrass 6.3 13.3 6.7 25.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Coontail 40.0 25.0 53.8 16.7 8.3 0.0 0.0 0.0 10.0 0.0 0.0Chara 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eurasian watermilfoil 0.0 0.0 7.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Common naiad 0.0 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 0.0Nitella 0.0 8.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Fries’ pondweed 0.0 0.0 7.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Eel grass 0.0 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 0.0




21

Water Clarity and Water Quality Table 9 summarizes Secchi disk readings taken in each Tier II survey on Hudson Lake since 2007. Although water clarity can fluctuate greatly based on weather, rain events, and algal blooms, it appears that water clarity in Hudson Lake has been relatively stable. Water clarity was slightly higher in 2007 than in all of the other years. Water clarity should continue to be monitored for any significant downward trends.

Table 9: Hudson Lake Secchi Depth History Date Secchi Depth 6/21/2007 15.1 8/17/2007 14.3 8/14/2008 13.0 8/21/2009 12.0 8/8/2012 12.0 8/12/2013 13.5 8/12/2014 12.1 8/13/2015 12.8 8/26/2016 12.5 8/7/2017 10.5

During the summer 2017 Tier II survey, Aquatic Weed Control collected data to construct dissolved oxygen and temperature profiles for Hudson Lake. These profiles are described in Figures 11 and 12. Hudson Lake has adequate oxygen to support fish life down to about 19 feet at the time the profile was recorded. Data from the temperature profile indicated a very weak thermal stratification beginning at a depth of around 18 feet.

22

Figure 11: Hudson Lake 2017 Dissolved Oxygen Profile

Figure 12: Hudson Lake 2017 Temperature Profile

02468

101214161820222426283032

0 1 2 3 4 5 6 7 8 9

Dep

th (f

eet)

Dissolved Oxygen (Mg/L)

Hudson Lake Dissolved Oxygen Profile8-7-2017

02468

101214161820222426283032

55 60 65 70 75 80

Dep

th (f

eet)

Temperature ( degrees F)

Hudson Lake Temperature Profile8-7-2017

23

Tier II Discussion There were 15 species of native plants found in the August 2017 Tier II survey, and native plant diversity was 0.86. Both of these parameters are high when compared to many other area lakes. The previously established native species richness and native diversity objectives were 16 species, with a diversity of 0.86. The native species diversity objective was achieved; however, native species richness objective was not achieved during the 2017 season. The contemporary objective of at least 62% (50/80 sites) of the sampling sites having plants was also achieved, with 52 sites having plants. These objectives were established to help evaluate the success of the plant management strategy. Three exotic plant/algae species were collected in Hudson Lake in August of 2017: Eurasian watermilfoil, starry stonewort and spiny naiad. Spiny naiad did not appear to be causing any significant impairment in the lake, and no treatments should be necessary. EWM was very abundant in numerous areas within the lake and was causing significant impairment prior to the 2014 herbicide treatments. In the August 2017 survey, EWM was collected at 6.3% for all 80-sample locations, at all depth contours. EWM frequency did decrease from 13.8% in 2016 to 6.3% in 2017. For 2018, the development of EWM treatment areas will attempt to maintain summer EWM frequency below 10%. Although SSW was only collected at 1.3% for all depth contours during the survey, this aquatic species should be closely monitored to ensure it is not increasing within the lake. It is recommended that the Hudson Lake Conservation Association (HLCA) aggressively attempts to control this invasive alga. Native Plant Trends Analyzing the data from surveys among 2014 through 2017, native plant diversity has ranged from 0.81 (2015) to 0.87 (2016) during Hudson Lake’s involvement in the LARE program. Native species richness has ranged from 14 species (2015 and 2016) to 17 species (2016-IDNR). It is very difficult to distinguish any long-term trend. If any long-term observation could be made, it would appear that native plant diversity and abundance are consistent. Among other parameters such as littoral depth, sites with native plants, and the average native species per site have also remained relatively consistent during the five summer surveys that have been completed during 2014 – 2017. Overall, the native plant community appears healthy, stable, and diverse when compared to many other Northern Indiana lakes involved in the LARE program. The main goal of plant management in Hudson Lake going forward will be to maintain this healthy native plant community, while providing seasonal control of EWM/SSW in areas of dense infestation. It is hoped that this plan will increase the utility of the lake and help native plants compete with EWM/SSW through selective treatments. Action Plan For 2018, all areas of EWM will be treated with liquid 2, 4-D herbicide at a rate of 2.0 ppm. It is recommended that funding be available to treat approximately 30 acres of EWM with liquid 2,4-D. The 2017 test plot to control EWM with granular Triclopyr will be abandoned during the 2018 season, as suggested by the Hudson Lake Conservation Association. Lastly, it is recommended that the association control as much of the newly idenitfied SSW as possible based upon their budget. It is estimated that as much as 15 acres of SSW could be present next season. Indiana Division of Fish and Wildlife – LARE staff recommends treating SSW with Cutrine Ultra at a rate of 2.4 gallons per acre foot and Hydrothol 191 at a rate of 1 quart per acre foot in open water and 1 quart per surface acre in confined water treatment areas. Another option is to treat SSW with Clipper herbicide at a rate 200 ppb. If SSW abundance is only identified within 2 to 3 acres, the consensus from lake managers is that Clipper herbicide will provide better control compared to the

24

Cutrine Ultra/Hydrothol 191 combination. In terms of cost, however, Clipper is more expensive to use than the Cutrine Ultra/Hydrothol 191 combination. For the 2018 season there will be no herbicide treatment for Phragmites control. Past herbicide treatments have been very successful in controlling this species in various locations around the lake. That coupled with the potential harm inflicted by SSW to the lake; it is suggested that the HLCA designate as much funding toward controlling SSW as possible. During the 2017 season there was an area of Phragmites identified that consisted of 0.51 acres. However, there was not a route to access the area and be able to adequately apply herbicide. Therefore this area did not receive herbicide treatment. Figure 6 displays the location of this area. It is important to note that the EWM/SSW treatments will not eradicate these species in Hudson Lake. The treatments should help native plants compete with EWM/SSW on an annual basis, while providing greater recreational access to the lake. The liquid 2,4-D strategy seems to be controlling EWM adequately in selected treatment areas and keeping EWM frequency manageable in summer Tier II surveys. Average depth of treatment areas is estimated to be up to 6 feet. EWM abundance in Hudson Lake varies from year to year, and treatment areas are best prioritized each year using a spring visual survey. Surveys and Planning A visual survey should be sufficient in the spring of 2018 to verify EWM and SSW locations prior to any herbicide treatments. A summer (post treatment) Tier II survey should be used to monitor EWM, SSW, and native plant populations. It is also recommended to update the AVMP following the 2018 season. 2018 Project Budget 80% - 20% Cost Share Items Treat up to 30 acres of EWM with liquid 2,4-D at 2.0 ppm. (4-6 ft avg depth) $9,300 Spring visual survey, summer Tier II survey, and AVMP update $5,000 LARE share for surveys, planning, and treatment of EWM (80%) $11,440 Associations share for surveys, planning, and treatment of EWM (20%) $2,860 Total cost estimate for 80/20 items $14,300 50% - 50% Cost Share Item Treat up to 15 acres of SSW - Cutrine Ultra at 2.4 gallons/acre foot (4 ft avg depth) Total Cost for 50/50 item

$10,000

LARE share for SSW treatment (50%) $5,000 Association share for SSW treatment (50%) $5,000 Final Combine Project Totals $24,300 Total LARE cost for project $16,440 Total association cost for project $7,860

25

Public Involvement Parties interested in the improvement of Hudson Lake include members of the Hudson Lake Conservation Association and anglers that frequently use the lake. The most common, and often most effective, methods for keeping the public informed about aquatic vegetation management practices are lake association meetings, as well as periodical newsletters sent out by the associations. It is recommended that association members encourage neighbors and other lake users to attend lake association meetings so that interested parties are well informed about the LARE program. Making sure that meetings are well advertised and planned well in advance of the meeting dates are ways to help ensure good attendance. Carry-in dinners, door prizes, contests, guest speakers, and discussion panels are all excellent ways to boost attendance, encourage involvement, and keep association members informed about lake management activities. The Hudson Lake Conservation Association held a public meeting on November 11, 2017, at Monroe’s Crossing restaurant. Several association board members including Bill Companik the president of the association attended the meeting along with Aquatic Weed Control Inc. staff. Aquatic Weed Control, Inc. staff summarized LARE program goals and outlined management options available for the control of Eurasian watermilfoil and starry stonewort. Six lake use surveys were returned. Figure 13 summarizes public survey results as well as written comments received at the meeting. Residents were primarily concerned about fish populations and too many aquatic plants within the lake.

26

Figure 13: Hudson Lake Public Meeting Survey Data

27

References Cited IDNR. 2014. Tier II Aquatic Vegetation Survey Protocol. IN Department of Natural Resources. Indianapolis, Indiana. Indiana Clean Lakes Program. 2010. Hudson Lake Data. http://www.indiana.edu/~clp/County%20pages/lake.php?Lake_ID=717 Scribailo and Alix. 2014. Aquatic Vegetation Management Plan for Hudson Lake, LaPorte County Indiana: 2013 Update. Aquatic Restoration Systems LLC. 1555 Coleman Street. Porter, IN 46304

http://www.indiana.edu/%7Eclp/County%20pages/lake.php?Lake_ID=717

28

Appendix Common and Scientific Names of Aquatic Plants in Hudson Lake

Bidens beckii Water marigoldCeratophyllum demersum CoontailChara spp. CharaElodea canadensis Canada waterweedHeteranthera dubia Water stargrassMyriophyllum spicatum Eurasian watermilfoilMyriophyllum verticillatum Whorled watermilfoilMyriophyllum sibiricum Northern watermilfoilMyriophyllum heterophyllum Variable watermilfoilNajas flexilis Common naiadNajas guadalupensis Southern naiadNajas marina Spiny naiadNitella sp. NitellaPotamogeton amplifolius Large-leaved pondweedPotamogeton crispus Curly-leaf pondweedPotamogeton friesii Fries’ pondweedPotamogeton gramineus Variable pondweedPotamogeton illinoensis Illinois pondweedPotamogeton natans Floating-leaf pondweedPotamogeton nodosus American pondweedCabomba caroliniana CabombaPotamogeton pusillus Small pondweedPotamogeton zosteriformis Flat-stemmed pondweedStuckenia pectinata Sago pondweedUtricularia gibba Humped bladderwortUtricularia macrorhiza Common bladderwortUtricularia purpurea Purple bladderwortVallisneria americana Eel grassPotamogetn robinsii Fern pondweedNitellopsis obtusa Starry stonewort

29

Data Sheet and GPS Coordinates

Date: 8/7/2017secchi 10.5

LatitudeLongitude

DepthSite

AlgaeEurasian w

atermilfoil

Spiny naiadChara

Sago pondweed

CoontailCom

mon bladderw

ortW

horled waterm

ilfoilPurple bladderw

ortIllinois pondw

eedFlat-stem

med pondw

eedSlender naiad

Eel grassCanada w

aterweed

Small pondw

eedAm

erican pondweed

Variable waterm

ilfoilVarible pondweedStarry stonew

ort41.715618

-86.5663183

13

141.714056

-86.566854

25

41.713828-86.565132

93

13

11

13

41.714353-86.565276

114

13

51

41.715715-86.563784

65

15

141.715191

-86.560015

641.715747

-86.5560457

73

13

41.716242-86.555206

98

51

41.715924-86.553566

139

541.716354

-86.55221517

1041.716341

-86.55061722

1141.71706

-86.54937121

1241.715203

-86.5533620

1341.714671

-86.55279423

1441.714635

-86.55449117

151

141.714296

-86.55532414

161

41.713816-86.555789

517

341.713767

-86.55486

181

33

11

41.713966-86.553617

1119

33

141.713842

-86.55269419

2041.712958

-86.5526324

211

41.712586-86.551394

622

51

41.713386-86.550235

1323

11

41.712497-86.549461

424

51

41.713651-86.54862

2125

41.713054-86.547808

1426

13

341.711947

-86.5472026

275

11

341.712722

-86.54658919

2841.712596

-86.54527923

2941.711789

-86.54555812

301

31

341.711695

-86.54414916

3141.71104

-86.5438156

325

13

41.71059-86.542163

433

31

11

41.711537-86.542284

2534

41.711194-86.541432

1635

41.711192-86.54075

1536

141.710515

-86.5401436

373

31

41.710073-86.538979

438

11

33

141.710776

-86.5382966

391

51

11

41.711797-86.539619

1640

341.712361

-86.54015425

4141.71272

-86.53938119

4241.711973

-86.53882711

4341.711804

-86.5372114

4441.712717

-86.5374276

453

33

41.713423-86.538189

346

31

11

41.713426-86.539081

1147

33

41.71405-86.539465

648

11

141.713466

-86.54012419

4941.714807

-86.54083514

5041.71553

-86.5407395

513

11

41.714961-86.541473

1852

41.715869-86.541889

1453

141.716455

-86.5416356

545

41.716038-86.542611

2155

41.716804-86.542999

1856

41.717393-86.54202

357

31

141.717733

-86.54300211

585

11

41.717363-86.544093

2159

41.718707-86.543743

760

35

11

41.717863-86.544688

1661

41.718559-86.544973

1162

53

11

41.718918-86.54572

263

11

31

41.718847-86.546974

664

541.717896

-86.54666917

6541.717492

-86.54758321

6641.718117

-86.54863411

673

41.719011-86.549593

468

13

41.717932-86.54979

669

51

41.717497-86.548679

2070

41.716732-86.552682

1171

31

11

41.716366-86.553318

1972

41.71727-86.554242

773

51

141.71778

-86.5535664

743

15

141.716665

-86.55452111

751

13

141.717824

-86.5563075

765

11

41.717526-86.558731

577

11

11

341.717227

-86.5630244

785

11

13

11

41.717229-86.564901

579

31

31

41.715652-86.565196

680

53

30

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31

2018 LARE Treatment Permit In the spring of 2018, treatment maps will be submitted to the District 1 Biologist and LARE staff after a visual survey of Hudson Lake.

33

Permit Maps The red and blue areas labeled on these maps are likely potential EWM treatment areas for 2018. It is important to note that the actual treatment areas will be developed from the spring 2018 visual survey and are likely to differ from these maps. A new map will be submitted to the IDNR for approval prior to any herbicide treatments in 2018.

35

The green area labeled on this map is a potential treatment area for SSW in 2018. It is important to note that the actual treatment area(s) will be developed in the spring of 2018 and are likely to differ from this map. In spring of 2018, a new map will be submitted to the IDNR for approval prior to any herbicide treatments.

36

Executive SummaryProblem StatementAquatic Vegetation Management History2017 Vegetation TreatmentsTier II Survey ResultsWater Clarity and Water QualityAction Plan2018 Project BudgetPublic InvolvementReferences CitedAppendixCommon and Scientific Names of Aquatic Plants in Hudson LakeData Sheet and GPS Coordinates2018 LARE Treatment Permit

dewart lake aquatic vegetation management › gf2.ti › f › 329890 › 8399525...tables 1, 2, and...

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