|West Pond 2006: Curly Pondweed— Potamogeton crispus infestation
I’m writing to let you know, as you may have surmised, that DEP is not conducting a plant removal effort at West Pond this spring. Based on last year’s effort and the extent of curly leaf found, we determined that hand removal would simply be maintenance control and is unlikely to significantly reduce the population.
Over the last few months we attempted to contract for a diver-assisted suction harvest (DASH) unit to see if this technology gives us the upper hand to make in-roads in the population. DASH essentially accelerates removal of plants by divers (assuming equipment and conditions are right). We know of two DASH units that would be good candidates for work on West Pond but were unable to contract for their services.
Here’s our plan for work on West Pond in 2006:
• We will use a network of grid points and a global positioning system to map the curly leaf infestation on the pond this year. We will then have a tool to accurately compare growth from year to year. While we mapped the curly leaf to the extent we could last year, we don’t have a systematic mapping approach that allows for comparison of plant growth (and spread or reduction) from one year to the next.
• We will work to execute a contract for DASH for 2007 for approximately 3 weeks of control work on areas identified in the mapping effort.
• We want to remind landowners on the pond to inspect boats carefully going out (and into!) West Pond for any plant fragments.
• We want to remind landowners that they may remove curly leaf plants affecting their use of the water adjacent to their properties. We also want to remind landowners, however, that removing plants with the hard vegetative parts known as turions may spread the plant even more in their immediate area.
• We will search Long Pond again to be sure there is no curly leaf in that water body.
Please distribute this information to Association members as it’s convenient for you.
Maine DEP Invasive Aquatic Species Program
SHS 17, Augusta, ME 04333
phone (207) 287-6110 fax (207) 287-7826
West Pond 2005:
Potamogeton crispus infestationHey Folks, the weed is more extensive than previously suspected. We need some help picking up fragments that have floated free. The leaves tend to float so anyone with a fish net or the ideal a swimming pool net could net the leaves off the surface. We have a supply of bags at Dennis Spinney’s camp.It is critical to get as many of the fragments as possible now. This will be a continuing effort for years to come. If you have row boats, canoes or just hip or chest waders we could begin the clean-up.It would be ideal during the week as the diver’s are harvesting, but not realistic for most of us working people. The next couple of weekends would be the best alternative. If anyone can help, please call me. Thanks, Joe.
DEP 2004 GPS points and estimates of bed size suggest there is approximately 1/4 acre of P. crispus in scattered beds. Most of the beds are in the shallow shelf near the west end of the pond. DEP also marked scattered individual plants along the shoreline in 2004, especially the north and east shore, but many of these may have been floating (not rooted) plants blown in by prevailing summer winds.
DEP divers attempted removal of one patch in June 2004 before realizing (thanks to local knowledge) that the infestation was must more extensive than originally thought.
Plant control options:
DEP staff consulted with John Madsen, an aquatic biologist at Mississippi State University with extensive experience with P. crispus in Minnesota and Wisconsin, about plans for controlling this plant. If the infestation is, in fact, approximately 1/4 acre of scattered beds, Madsen thinks hand removal is a reasonable approach to keeping the population in check. Other techniques discussed with Madsen include diver-assisted suction harvest, benthic barriers and herbicides.
Hand Removal of P. crispus in 2005
Note: From his experience in other northern states, Madsen estimates that the plants will begin forming turions in late May. We should therefore conclude hand removal efforts before the last week in May (target May 20 as last day to give a few days buffer into the following week).
DEP will use contracted divers to remove the plant beds located in 2004, survey the perimeter of these beds and remove any plants found, and survey the shoreline for individual plants and other beds missed in 2004. Following is an outline of steps to prepare and implement this project. George Lord, contractor, will coordinate this project for DEP and will be on site during removal efforts.
Mid-April. George Lord (contractor) will:
• produce bouys/anchors (20-25) for deployment at plant beds
• call local contacts to arrange boat access, overnight docking for his boat, and plant disposal (see contact information below).
• contact divers directly (get information from Karen) to arrange hand removal for weeks of May 9 and May 16, and maintain contact during that period to ensure project completion; if time permits conduct additional plant survey work after hand removal to make sure we didn’t miss anything.
April 27 or 28. McPhedran and Lord mark beds with buoys using pre-loaded points on Trimble GPS.
May 9-13; May 16-20. Hand removal with contracted divers will occur within this time period, but may not require the entire two weeks. As described above, the objectives are to:
1. remove the plant beds located in 2004 and marked with buoys in early 2005. After removing from a specific bed divers should return to the same bed later that day or the next day once visibility improves to remove remaining plants missed the first time through
2. survey the area immediately surrounding these beds and remove any individual (or small patches) found
3. survey the shoreline of the pond and remove and plants found
Madsen guesses it might take 3 or 4 days for initial removal of the ? acre but it’s hard to say. We’ve allocated 10 days to meet all of the above but expect it will take less than that. One day assumes 8-10 hours of dive time (4-5 hours per diver); total dive time allocated is 80-100 hours.
SCUBA v. Snorkel. Once the initial beds are cleared, Madsen suggests that divers switch to snorkeling for objectives 2 and 3 above. Snorkeling affords a larger field of view that would help in finding individual plants. Then the snorkeler could dive down to uproot and remove the plant. But if there are dense beds or patches we’ll definitely want to use SCUBA.
Local contacts to arrange access, docking, plant disposal:
Joe Howes, West Pond Association President
(207) 625-3667 home
(207) 439-4323 home
(207) 625-4743 camp
Arlene Garside – possible launching site on her beach
Equipment (indicates whether DEP or George Lord (GL) will provide)
Boat (GL, DEP to reimburse)
View Scope (DEP)
Buoys (GL, DEP to reimburse for rope)
Garmin GPS to mark sites where plants removed (DEP)
Bins for plants (DEP and GL)
Invasive Species Program
ME DEP Lake Assessment Section
SHS 17, Augusta, ME 04333
(207)287-6110 (fax -7191)