Lake & Environment Report – September 2014
By Charlie Bodenburg
Director of L&E
Once again I must say that we have had an interesting season this year. This past extended
winter and prolonged freeze, along with our Drawdown program initially came across as
successful overall.
The late freeze killed off most of the typical shoreline problem weeds, but the weather only
delayed nuisance aquatic growth through mid June. Typically, we experience nuisance growth
beyond the shoreline by early to late May, and it is dealt with in the approved manner.
In July, August, and September, our L&E employees assessed each lake and dam every
morning. They cleaned up the shoreline nuisance weed growth and removed any algae bloom
accumulations at the spillways.
Besides the persistent blue green algae growth at Fawn Dam, and several smaller patches
along the north side of Gold Key Lake, the larger issues were the submerged aquatic growth
along the south side of Gold Key Island and into the south cove by the causeway, and the
funnel algae mats that continued growing in Autumn Lake and at Fawn Lake spillway.
These problems were the effect of increased amounts of nitrogen and phosphorous in the lake.
Combined with low alkalinity values, our Lakes were susceptible to acid rain, which caused
significant fluctuations in pH following a rain event. Ecological Solutions report’s constantly
indicated that all of Gold Key’s Lakes were nitrogen fixing throughout the season, meaning that
they didn’t need the nutrient phosphorous to create algae.
On August 27, 2014, we had an Algae Bloom on Gold Key Lake. Ecological Solutions treated
the southern half of Gold Key Lake starting several hundred yards north of the Main Beach and
down to South Beach and around the island. The DEC restricts treatment to no more than ½
the lake’s surface at any one time. The DEC also requires 48 hours between subsequent
treatments. According to Ecological Solutions, the north half of the lake did not require
treatment 48 hours after treating the south half of the lake.
We have been experiencing various degrees of algae blooms in all of Gold Key Lakes starting
in late June. The problem we experienced on August 27 was an anabaena algae bloom with a
dose of nitrogen-fixing blue-green algae. Blue-green algae are a primitive organism that is not
really algae. They photosynthesize like algae, but they are actually bacteria.
Anabaena is capable of producing neurotoxins, although it is extremely rare for them to cause
toxicity. No human deaths have been directly associated with these toxins, although they can
cause skin irritations or nausea. Farm animals and pets have been killed by the toxins if they
drink waters containing toxic blooms, especially the heavy surface growth or scum near the
shoreline.
According to Ecological Solutions, the conditions we are experiencing are caused by the lake
“turning over”; Lake turn over is the process of a lake's water turning over from top layer to
bottom layer. Gold Key Lake is our only lake that stratifies (form into layers); Autumn Lake and
Fawn Lake do not stratify.
Normally during the summer, the surface layer is the warmest because it is heated by the sun.
The deeper layers are coldest because the sun does not reach the darker layer. The daytime
temperatures have been in the high 70’s while the overnight temps have been in the high 40’s.
The warmer surface water begins to cool over night, as the water cools it becomes denser
causing it to sink. This caused the "turning over" the layers.
Throughout the season, we have had heavy submerged vegetation growth in the far southern
cove of Gold Key Lake entering the causeway. Ecological Solutions has felt that this growth
has become too dense to control manually and was not good for the fish population. In their
reports, Ecological Solutions stated that the fish cannot maneuver in such dense weed growth
and forage. The challenge continued to be collecting and harvesting the cuttings ahead of the
growth.
Ecological Solutions is referring to the baitfish population, as ‘not being able to maneuver and
forage’. Large populations of baitfish directly influence how many big bass can be grown per
acre. This especially affects the bass spawning habitat around the island by limiting the
available food source.
In managing our lakes properly, our management emphasis should be on producing, growing
and creating the right habitat for the bluegill and baitfish – as stated in our Lake Management
Plan. This is done in many trophy producing bass lakes around the country.
Harvesting, without the proper equipment is neither cost effective nor provides a long term
benefit. Chemical application may be cost effective, but does not provide a long term benefit
either. The solution is a combination of both – treating specific problem areas as growth
appears, and then keeping them mechanically maintained.
Starting in July, we deployed two – 2 man boat crews harvesting algae from Autumn Lake. The
two crews were then deployed around the Gold Key Island to hay-rake harvest weeds in the
channel. One crew loaded up aquatic vegetation into a garbage boat while the other crew
shuttled and emptied the loaded boat.
Our cutter system with the necessary support equipment established and maintained a
navigable channel between deployed buoys around Gold Key Island. The “path” provided a
point of origin to “mow” from and a line-of-sight to navigate by. This system is very labor
intensive and lacks a method to properly harvest the cuttings.
This deployment cost approximately $16,000 between July and now. A proper harvesting
system would provide more than 4 times the productivity at less than ½ the labor cost. We are
looking into a cost effective system to facilitate for next year.