Aquatic Vegetation Management Plan
Submitted by Patrick Wiltshire, Chair, Water Quality Committee
Under contract with our lake association and funded partially by a LARE grant, Aquatic Weed Control, Inc. (AWC) of Syracuse, IN have completed an update to the Aquatic Vegetation Management Plan (AVMP) for Oliver, Olin and Martin lakes for the 2016 season. Click the following link to view the full report:
Highlights of Report:
In the Spring of 2016 AWC staff treated a total of 4.79 acres on Martin Lake to treat the invasive Curly Leaf Pondweed (CLP). Although some instances of the invasive Eurasian Water Milfoil (EWM) was mapped on Martin Lake, no treatments were applied in 2016. No invasive weed treatments were done on either Olin Lake or Oliver Lake in 2016.
A weed survey was then conducted in late July and found that presence of CLP and EWM had expanded on Martin Lake to a level where treatment of both would be recommended for 2017. While some increases in CLP and EWM populations were found on Oliver Lake they were not substantive enough to recommend treatment in 2017.
Plant diversity for all three lakes is slightly above average for similar lakes; however, Martin Lake has more diversity than either Olin or Oliver Lakes, which are both considered to be somewhat sparsely populated with aquatic plants. Given there is no at-speed boat traffic on Olin Lake nor have any invasive weed treatments been done on Olin Lake, it is very unlikely that either is a cause for the lack of plant diversity and volume on either lake.
Lake clarity is still quite good in all three lakes but generally better in Olin and Martin Lakes than Oliver Lake. However, since 2008, eight sets of secchi-disk measurements have been taken and the average transparent depth reading for Oliver Lake is 9.4 feet deep while in 2014, 2015 and 2016 the measurements were 6.0, 8.5 and 6.5 feet respectively. It's difficult to say this is a downward trend because a number of things can affect water clarity on any given day – the biggest being boat traffic on Oliver Lake. But it is something to continue to watch carefully. Thanks go to Dr. Lynn Bowen for faithfully taking our secchi-disk readings as part of the Indiana Clean Lakes Program.
Dissolved oxygen (DO) is an area where Oliver Lake shines. Levels of DO are sufficient to support fish habitat to depths of up to 40 feet, which is considered very rare in the Northeast Indiana lakes. This is partly why the IN DNR continues to stock an ample supply of brown and rainbow trout in our lakes for sport fishing. Nearly 15,000 trout fingerlings have been released into Oliver Lake in each of the past two years.
2017 AVMP LARE Grant Award:
Our lake association again applied for a LARE grant to continue monitoring the aquatic vegetation of our lakes chain and we were awarded a total grant of $10,160 to fund an updated aquatic vegetation management plan as well as treat 10 acres of Martin Lake as well as the channel between Olin and Martin Lake in the Spring of 2017. The association's maximum matching-cash portion would be $2,540.
Requests for proposals were sent to five area vendors and the contract was awarded to AWC, Inc. of Syracuse for the 2nd year in a row. The contract specifies a price of $5,400 for the AVMP update and $5,293 for the treatments on Martin Lake and channel. This will require a cash-match of no more than $2,140.
Representatives of AWC, Inc. will be on all three lakes in late April or early May to conduct a sample survey of invasive weeds, and will determine when the time is right to apply treatments for CLP and EWM in Martin Lake and the channel. Again, the reason timing is so important is that the invasive species of aquatic plants emerge from the floor of the lakes and channels before the native species do, allowing a short window in which the invasives can be treatment with little to no risk of harming native species.
In late July or early August a representative of AWC will conduct a public hearing to share the results of their spring and summer surveys as well as their overall thoughts on the aquatic health of our lakes. We will provide you with an update as to the date, time and location of this hearing at a later time.