Suction & Hand Harvesting
- Suction harvesting is a vital component of SDRA’s efforts to manage milfoil and reduce the need for treatment with herbicides. It is a labor-intensive project that requires many hands to make it happen. We currently have 4-5 divers, and they are clearly a vital part of the teams; but there are also a variety of essential other roles for people of all ages. Suction harvesting cannot happen if divers do not have support. Get your contact information to Aaron or Art ASAP so that they will know whom they can call on when suction harvesting dates & times are available. (As always, selected dates are always weather dependent.)
- Anyone spotting milfoil should, if possible, mark the spot with a floating object that can readily be seen and also report this information to Aaron Colaluca (firstname.lastname@example.org).
- “Eyes on the Lake” is a concept that requires ALL SDRA members to pay attention to their surroundings and take action when problems are observed. This means notifying our Lake Management chairpersons: Aaron & Art. Last year, one positive outcome of “Eyes on the Lake” was that phragmites were identified and removed by hand harvesting from the area near the Hanley/Fortuna property and also near the Fournier property.
PROGRAM PLAN: Suction Harvesting (2021-22)
Chair/Lead Persons: Aaron & Art with assistance from Eric, Justin, Dennis, Rico, Judy, Jason, Cleo & Deb & Others
OBJECTIVES: To reduce the invasive species known as variable leaf milfoil and prevent its spread by tackling “hot spots” in shallower waters.
|DATE||ACTIVITY||WHO IS INVOLVED||$$ NEEDED||OTHER HELP NEEDED OR COMMENTS|
|June||Assemble Suction Harvester.||Aaron, Art||$1000 in June 2021; typically $50||Replace flooring on SDRA’s Suction Harvester|
Support materials such as bags to hold the milfoil.
|June||Determine training dates; advertise them.||Aaron, Art, Board||Update list of trained divers; all participants must sign a liability waiver form prior to participating in DASH . send copy to secretary for filing.|
|July – August||Conduct harvesting||Aaron, Art & Teams||$||Send information to secretary to convey results (e.g.estimated pounds of weeds removed or sacks of removed milfoil)|
|Sept.||Disassemble harvester; prepare list of items needing replacement & purchase for next season||Aaron, Art|
We did it! After months of fundraising, grant writing, and membership drives, SDRA accumulated enough capital to purchase a Suction Harvester. Our Lake Management Committee did significant research and made recommendations to the SDRA Board. Together, we considered types of equipment, the level of our treasury, the costs associated with the expenditure, and the possible benefits. Ultimately, SDRA made the decision to go ahead and purchase a Suction Harvester from Aquacleaner.
A Suction Harvester is designed to suck up any type of solids that will pass through a hose. By manipulating a hose- — which takes a lot of practice and grace — a diver extracts unwanted plants and solids right from the rooting system, so they don’t grow back as fast. The machine is equipped with filtration that allows the water to pass through it, while capturing plants, rocks, sticks, leaves and assorted debris. This machine is an environmentally friendly means of dealing with an overwhelming problem.
Aquatic vegetation grows and dies each year, sending the skeleton of the plant to the lake’s bottom. There, the plants decompose and fragment. That increases the density of the plants in following seasons and adds to the buildup of organic sediment. Suction Harvesting slows this process down and, over repeated use, may halt the cycle. In contrast with chemical treatments or weed cutters, a Suction Harvester has the advantage of selectivity. If we want only the milfoil removed but want the lily pads to remain untouched, we can do so.
There are several criteria that must be assessed to determine the rate of progress (ROP) that we can achieve using the Aquacleaner Suction Harvester. These include:
- Type of plant: A plant’s rooting system dictates how fast we can remove this year’s plant. We’ll attempt to get both this year’s and last year’s plants out.
- The type of bottom – Soft, silted in bottoms like those in Smith & Sayles Reservoir make plant removal and its rooting system easier to extract than if we had hard bottoms like clay or sand. Those require more suction to get to the rooting system of the plant.
- The density of the plant: This means that we have to consider how many plants are in a given box as well as how tall they are. More Biomass requires more time to go through a given area.
- The Depth of the water: Deeper water slows the rate of progress due to the logistics of moving around while under water and the size of the plants involved.
- Other: Sometimes there is debris in the area that needs to be cleaned. Leaves, sticks, rocks, and larger items must be removed as part of a shoreline remediation and to maximize use of the lake.
If you’d like to use the Suction Harvester around your property, you must meet several criteria: 1) You must be a SDRA member in good standing. 2) You must be fully trained to use the Suction Harvester. 3) You must sign a liability waiver. Trainings are available for interested SDRA members. Please contact Rico Colaluca at 401-568-4267 to set up trainings.