Hi everyone, I live in NE Connecticut in a community where 11 households share ownership of a 7 acre pond fed by runoff from surrounding land that is about 15 feet deep in most areas, shallower near the shore where we have water lillies. My wife and I enjoy swimming in the water. Fishing catches mainly crappies and large mouth bass. Pond water is dark from dissolved tannins but very clean. We've been monitoring phosphate levels for years and been lucky that they stay low, most of the pond is not bordered by lawns or fertilizer. Waterlillies cover the periphery of the pond. Over the last ten years we witnessed invasive growth of Eurasian milfoil. Last year the majority of our lot owners agreed we had to do something to get rid of milfoil. We hired a company called "Pond and Lake Connection", they told us about an herbicide ProcellaCOR, a modified plant growth hormone that was very effective in killing invasives at very low concentrations and with very minimal side effects. We paid $6k for a one time treatment. Milfoil disappeared within days. Dissolved oxygen dropped as expected since milfoil was being decayed, but did not adversely affect fishing.. at least no dead fish.
The one unexpected side effect was reduction of water lillies. Some of the roots (rhizomes) apparently died and floated to the surface this year... I've pulled one out and it's very light, full of air pockets. We've also seen a number of what we call floating island muck mats. They contain rhizomes and apparently float up with surrounding bottom muck still attached. Some areas of lillies died, but many are being replaced by new growth. Overall we've pleased to have gotten rid of the milfoil, but curious about how the muck mats and how long they will be take to sink back into the muck... or whether they will stay afloat? Curious to know if anyone else has experience with this type of situation.
The mats will eventually sink, how long it takes will depend on the weather, wind, rain, and temperature. My dad's old pond with eurasian milfoil (no water lilies) used to get similar floating mats, they would usually disappear in a few weeks.
