Submitted by Workingmomof3boys t3_110in1h in Connecticut
https://www.youtube.com/watch?v=QyZ_yRQwNvQ
You can see the explanation in the video linked above. It turns out the sterile grass carp that were introduced into the lake in 2008 and again in 2015 appear to be the cause. When the carp were introduced for the second time (and in much greater numbers), no one considered that while the carp would not reproduce, they would grow larger as they feasted on the milfoil and then consume even more! Unfortunately, because the power company that owns the lake needs to make repairs to the dam this year, they're doing a deep drawdown, which is not going to help regenerate plant life. I think that ultimately, the lake will probably recover, but finding the right balance between no plant life (which will destroy the lake's ecosystem and kill its fish) and too much plant life (such that it chokes the lake and prevents enjoyable recreation) is not going to be easy.
octo2195 t1_j8931tf wrote
The sterile grass carp were never intended to reproduce, hence being sterile. This is a program modeled on the one (first in the state) at Ball Pond in New Fairfield, CT which has been very successful.
The deep draw down has been done in the past on Candlewood Lake to expose the plant life along the shore to cold air to help control the weeds. The draw down to make repairs will most likely not have any major impact on the plant life along the shore this year as it is no where near as cold as necessary to be effective.