2018 early-spring curlyleaf pondweed delineation · 2019. 2. 16. · freshwater scientific services...

CLP Delineation North Arm Bay (Lake Minnetonka; Hennepin Co, MN) – May 2018

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2018 Early-Spring Curlyleaf Pondweed Delineation North Arm Bay – Lake Minnetonka (#27-0133-13) Hennepin County, MN Surveyed May 15, 2018

Survey, Analysis, and Reporting by: James A. Johnson – Aquatic Ecologist, Freshwater Scientific Services, LLC

15771 Creekside Lane Osseo, MN 55369 [email protected] (651) 336-8696



Purpose of Survey

This early-spring survey was designed to locate and delineate areas of curlyleaf pondweed (CLP) in North Arm Bay of Lake Minnetonka (#27-0133-13). This information will help to guide CLP management in the bay, and is required as a part of the DNR permitting process for herbicide treatments.

CLP Delineation Survey Freshwater Scientific Services surveyed North Arm Bay on May 15, 2018. During this survey, we navigated a meandering path over designated portions of the bay, with a focus on areas that supported dense CLP in 2017. While navigating this search path, we used a combination of surface observations, rake tosses, and sonar readings to locate and delineate areas of CLP growth. We conducted rake tosses to assess CLP abundance at ~200 locations. At each of these locations, we dragged a sampling rake over approximately 10 square feet of lake bottom and recorded the CLP density based upon the number of curlyleaf plants (stem count) retrieved on the rake. We used a hand-held Garmin GPS unit (GPS-MAP78) to record each of the sampled locations, and documented water depth, native plants present, CLP plant height, and CLP abundance (rake density rating; 1 to 3 scale as described below). The recorded water depths, CLP plant heights, and rake densities were linked to the appropriate GPS locations and then mapped using desktop GIS software.

CLP Rake Density Rating for Early-Spring Delineations

1 = 1 to 2 stems per rake toss 2 = 3 to 9 stems 3 = 10+ stems

Survey Method



Surveyed: May 15, 2018 Method: Visual, Rake, Sonar Surveyor: JA Johnson

N

North Arm Bay – Lake Minnetonka (#27-0133-13) Curlyleaf Pondweed Delineation Survey: May 15, 2018

Map produced for PLM Lake & Land Mgmt by:

15771 Creekside Lane Osseo, MN 55369 fixmylake.com (651) 336-8696

CLP Rake Density

1 2 3

1 2 3

May 2018

May 2017

Proposed Plots

Surveyed Path



N

Proposed Plots

North Arm Bay – Lake Minnetonka (#27-0133-13) Curlyleaf Pondweed Delineation Survey: May 15, 2018

Plot Area (acres)

Mean Depth

(ft)

Mean CLP

Density (0-3)

1 30.1 6.4 2.6 2 7.7 5.3 2.3 3 7.7 5.0 2.3 4 3.8 4.9 2.2 5 12.0 5.3 2.3 6 0.9 4.2 2.4 7 2.4 6.1 2.5 8 2.6 7.8 2.0

Total 67.2

1

2

3 Surveyed: May 15, 2018 Method: Visual, Rake, Sonar Surveyor: JA Johnson

Map produced for PLM Lake & Land Mgmt by:

4

5

6

7 8

15771 Creekside Lane Osseo, MN 55369 fixmylake.com (651) 336-8696



Online Resources & Contacts

Minnesota Administrative Rules for Aquatic Plant Management https://www.revisor.mn.gov/rules/?id=6280 Minnesota DNR – Aquatic Plant Management Regulations & Permit Application Forms http://www.dnr.state.mn.us/apm/index.html

Keegan Lund Invasive Species Specialist Minnesota DNR [email protected] (651) 259-5828 Wendy Crowell AIS Management Coordinator Minnesota DNR [email protected] (651) 259-5085

2018 early-spring curlyleaf pondweed delineation · 2019. 2. 16. · freshwater scientific services...

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