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designed by
(updated 5/1/11)
(updated 5/1/11)
Mohawk Sportsman Club Application
NEW Mohawk Sportsman Club
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Updated May 14th, 2012
TOPICS of Discussion
* 2011 OLMS CLAM Water Clarity Results * Current Lake Conditions * The Role of Submersed Aquatic Vegetation *New Mohawk Sportsman Club Website
2011 OLMS CLAM Water Clarity Results
Lake Mohawk when compared to most other lakes in Ohio has some of the most pristine water quality characteristics in terms of water clarity and nutrient status. Clean water lakes such as Lake Mohawk are very rare in a state dominated by agriculture.
Below is a graph (Figure 1) that was recently published in the Ohio Lake Management publication that indicates that Lake Mohawk was 3rd out of 27 lakes monitored for water clarity in 2011.
Most lakes have less than 1/2 the water clarity that Lake Mohawk has as measured on a yearly average. It is VERY important to understand what the primary cause is for the loss of clarity in a lake. For example, in Lake Mohawk, there is a "situational loss" of water clarity primarily (not solely) caused by recreational activity such as the use of motorized watercraft in a relatively shallow water lake. Re-suspension of sedimentary nutrients cause mid summer algal blooms that would otherwise be less intense and less prolonged without the disturbance of sediments from intense summer recreation.
Figure 1.
Current Lake Conditions (As of May 7th, 2012)
Spring is here and with it comes the growth of land and lake vegetation. As mentioned below, the first reports of lake "issues" this year were the result of pollen grains from trees, flowers, bushes, etc.. floating on the surface of the lake. Steady winds sometimes caused these pollen grains to accumulate in various areas causing what looked like an "algae bloom".
On May 7th, 2012, a complete survey of the lake was conducted in order to map and assess the lake for potential nuisance aquatic growth. The 2011 targeted treatment for Eurasian watermilfoil (EWM) was extremely effective based on 2012 post-treatment observations. The only signs of EWM were floating fragments of plants originating from the back of Bay 11. In order to further isolate the source of the remaining EWM in Bay 11, further sampling and site visits to Beacon Lake will be conducted.
Curlyleaf pondweed (Potamogetan crispus) (CLP) was observed to be SPARSELY located in various locations throughout the lake (figure 3). As mentioned in prior years reports, most of the CLP will naturally end it's life cycle in mid-June WITHOUT any need for chemical control. The density of CLP in high recreational use areas is what I believe is the most important consideration in the chemical control of this plant.
IMPORTANT: The fact that CLP naturally "dies off" (senesces) in June and that CLP plays a vital role in the health of Lake Mohawk fisheries (see the role of SAV below), it is important to reach some level of compromise of where and how much of CLP should be controlled. Most of the CLP grows in water depths of 6-10 ft. at Lake Mohawk. Based on the needs of both recreational boaters, skiers, and fishermen, I believe that maintaining CLP growth in near shore areas that are not used for swimming and too close to shore for skiing is a good compromise. On May 9th, 2012, dense areas of CLP were targeted for chemical control as was areas that were typically used for lakefront swimming areas. The Main Beach and West Beach were targeted for CLP control in order to prepare for the Memorial Day weekend. Further treatment for CLP will be applied as warranted within the next two weeks depending on the level of growth and location.
Figure 2 Photo of Curlyleaf pondweed
Figure 3 2012 Areas of Curlyleaf pondweed
The Role of Submersed Aquatic Vegetation (SAV)
For an excellent summary of the importance of Submerged Aquatic Vegetation in lakes, please click on the SAV Document "button" below . Aquatic plants not only provide excellent habitat for a healthy fisheries, they also provide "purifying" effects for those recreational users that come into contact with the lake water such as swimmers, skiers, etc.. Our goal at Lake Mohawk remains to manage aquatic growth not to eliminate it.
The role of SAV in Lake Mohawk plays an integral role in the natural suppression of blue-green algae blooms. Lake Mohawk is extremely fortunate in having NOT to deal with Harmful Algal Blooms the way the State of Ohio is currently having to deal with HAB's in many State lakes.
March 24th 2012 Pollen in Lake Mohawk?
I received an e-mail in March from a Lake Mohawk resident that prompted an investigation into what was causing surface "scums" of what at first appeared to be "algae" concentrating at the north end of the lake.
"Are we losing the blue green algae battle already? This photo was taken 3/20/12 from dock area 13" Signed, Concerned Mohawk Resident
Telephone calls to the Lake Mohawk Sheriff patrol also reported seeing "oil spills" on the lake.
Explanation Below
On March 23, 2012, Eric Howland and I made a 360 degree drive around assessment of Lake Mohawk. Temperature data and water samples were taken for microscopic evaluation at various locations throughout the lake.
Results
The predominant floating material on the lake which appears to be algae, oil, etc., is actually POLLEN
Yes....the early Spring has resulted in the release of billions of pollen grains from various plants that float in the air, some of which end up on the surface of the lake.
Lake Mohawk Sample taken 3/23/2012 Original magnification 50X
ALSO Happening at this Time
"A Spring Diatom Bloom"
As some of you may remember from our "Seasonal Successional Planktonic Algae Graph"
Spring is a time when a group of algae known as diatoms become abundant. Diatoms are encased in a silica (glass) shell and come in many different shapes and sizes. The golden brown pigments of diatoms gives the water a brownish cast and are mixed throughout the water column.
Planktonic (free floating) diatom known as Asterionella sp. Lake Mohawk, March 23, 2012
Spring Summary
The mild winter and the warm spring will undoubtedly have an impact on Lake Mohawk in terms of biological productivity. Temperatures between 3-5 feet in the lake measured between 63-64 degrees on March 23, 2012. Oxygen values within the lake between 3-5 feet (8:15 a.m. - 9:30 a.m.) were supersaturated with oxygen most likely from the diatom bloom. Worldwide, diatoms produce more than 50% of earth's oxygen through photosynthesis. Also, some of you may be familiar with filter material that is made out of the "glass" shells of diatoms known as DE or diatomaceous earth. More information about diatoms can be found at : http://en.wikipedia.org/wiki/Diatom
end update
Welcome to the Lake Information site the Lake Mohawk Property Owners Association.
This site is dedicated to keeping the members of the L.M.P.O.A. informed about the water quality of Lake Mohawk. This site will be updated as new information becomes available and will discuss issues such as water quality, fishing, nuisance aquatic plant and algae control, and other general topics of interest. If you have any comments, questions, or suggestions for this web site, please contact me at your convenience. JeffGray@GraysAquatic.com Photo or Video submissions are always welcome.
Monday Night Fish Tournament
Click or scroll down
2012 Lake Mohawk Restoration & Protection Committee
Eric Howland - Chairman Scott Noble Ron Tschantz Robert Greene Joe Jacko John Fawcett Kevin Myszka
Quick Navigation (click on category)
IV. Lake Treatment (Actual & Proposed Dates, Areas, Chemicals, etc) VI. A well balanced lake for BOATING, SKIING, SWIMMING, and FISHING
Phosphorus Information July & August Shallow Bays + Increased Boating = Increased (P)hosphorus 80+ degree water temp + (P)hosphorus = Blue Green Algae
Find out why? Read Below
Side Image Scan by Jeffrey Falkowski - Lake Mohawk Sportsman Club (trenches in lake sediment made by propellers)
Information collected over the past several years indicate that the blue-green algae blooms that occur within Lake Mohawk during the months of July & August are primarily the result of "INTERNAL" sources of phosphorus from lake sediments.
The TWO MAIN INTERNAL sources of phosphorus are:
1) Lake Sediments being mixed into the water column by boat, wind, and wave action. (see Jeff's side image scan above)
2) DEEP (>18 ft) water release of phosphorus from the sediments when oxygen becomes depleted.
Complete Phosphorus Data to Date
click to download
Summary Statement
Three sets of phosphorus tests have been collected to date. May 5th, May 31st, and July 5th (2011). On May 5th, all inputs to the lake were tested for phosphorus in addition to testing various sites within each bay, the main axis of the lake, and the dam outlet.
July 5th, 2011 testing revealed significant increases in phosphorus compared to the May 31st testing period EXCEPT for bays 12 & 4. Bays 9/10 and bay 11 contribute a significant amount of phosphorus to the lake.
Shallow bays combined with increased July 4th boating activities are believed to be the primary reason for increased phosphorus concentrations. As the side scan image of Jeff Falkowski clearly illustrates, boat traffic mixes phosphorus laden lake sediments into the water column. Increased phosphorus and higher water temperatures in July & August "fuel" blue-green algae blooms.
Solutions to this issue are currently under study, discussion, and review by the Lake Mohawk, Lake Restoration & Protection Committee
Phosphorus Data Test Sites
Human health and property values of ALL L.M.P.O.A. members are affected by the water quality of Lake Mohawk. In order to understand the various factors that have the most impact on the lake, I have constructed a diagram of interactions that exist between property owners, lake users, aquatic plants, blue-green algae, phosphorus, and copper.
Blue-green algae (photo below - microscopic "plant like" bacteria) blooms are potentially harmful to humans and wildlife due to the production of toxins under certain conditions. The severity of health impact depends on the type of toxin as well as the route of entry (ingested) or location of contact (skin/eyes). Blue-green algae may also negatively impact the ecology of the lake (i.e. fishing) by reaching a point where it shades out light to bottom growing beneficial plants. For this reason, controlling blue-green algae in a manner that does not jeopardize the long term "health" of the lake (which directly affects property values) is the primary lake management objective at Lake Mohawk.
July 2009 Blue-Green Algae Bloom
Photomicrography by Jeff Gray
In the past, copper sulfate has been the primary control method used to address blue-green algae blooms. In addition, other chemicals were used to eradicate aquatic plants in a non-selective manner. Considering the fact that copper sulfate is not biodegradable, it accumulates in the lake sediments where it becomes increasingly toxic with increasing concentrations (applications). High levels of copper in lake sediments is damaging to both aquatic life as well as property values.
Fortunately, there are natural methods of suppressing blue-green algae which costs nothing and significantly reduces the use of copper algaecides. Maintaining a low growing population of "beneficial" aquatic plants helps stabilize the lake sediments which reduces sedimentary re-suspension of phosphorus back into the water column (which then "feeds" further blue-green algal blooms). While aquatic plants can be a nuisance in the most shallow sections of the lake, they do play important roles in the lake which include "purifying the water", providing necessary cover for a healthy fisheries, and reducing shoreline erosion. The aquatic plant management strategy at Lake Mohawk is to control tall growing exotic species of plants (i.e. Watermilfoil/CLP) while promoting non-nuisance species of low growing forms including the advanced forms of algae known as Chara/Nitella.
Grays' Aquatic Services Lake Management Philosophy and Mission Statement
By working with "Mother Nature", you can enhance the recreational value of freshwater aquatic ecosystems such as Lake Mohawk. Selective and judicial use of aquatic herbicides which promotes natural competition from native low growing aquatic plants, along with selective harvesting can all work together as an integrated approach to improving property values, sport fisheries, as well as recreational usage from skiers, pleasure boaters, etc.. Studying and controlling the sources of phosphorus will also naturally reduce or eliminate the threat of toxic blue-green (cyanobacteria) algae blooms (more later).
My mission at Lake Mohawk is to serve, educate, and answer all questions about the aquatic ecosystem that is the focal point of this beautiful lake community. It is my desire to further enhance the existing fisheries while minimizing any negative impacts this may have on recreational boating, etc.. Monitoring the "health" of the lake and posting my results on this web site is also a priority. Above all, I am here to serve the greater good of the Lake Mohawk Property Owners Association and will at anytime be available to answer questions or to respond to concerns or observations regarding lake conditions.
As of September 9th, 2011
Water clarity (transparency) is improving as we move past the blue-green algae "season". Algae suppression treatments have kept the blue-green algae at minimal levels without significant disturbance to non-target aquatic organisms.
Selective treatment for nuisance levels of Naiad sp. control have been applied.
A significant amount of beneficial Chara/Nitella (photo below) has been observed in Lake Mohawk. This advanced form of bottom growing algae helps crowd out undesirable plants as well as stabilize sediments from releasing phosphorus. Considering that Chara and Nitella are actually forms of algae, copper will kill this beneficial growth when applied in too high of concentrations. Another reason to keep copper doses low when controlling summer blue-green algae.
CHARA
Scheduled Lake Treatment Dates, Areas, and Chemicals
Nuisance aquatic plant and algae control is complete for the season as of September 14th, 2011. Remaining plants and algae will provide beneficial habitat for a healthy and productive 2012 fisheries.
by Joe Jacko
A fish tagging project that was planned for the current season has been postponed due to increased early water temperatures. High water temperatures can place additional stress on fish by reducing dissolved oxygen concentrations. The fish tagging project is expected to resume this Fall (2011).
If you can mention if any one would like to participate in the Sportsman Club Monday night tournament new faces are always welcome :)
OUR LAKE MOHAWK FISHING EXPERTS
Dave 2.29 pound bluegill caught June 5th, 2011 - "Johnny Jr." having fun in Bay 8
This photo is from May 15th, 2010. This little girl caught her first Bass on artificial bait dragging a tube in the marina.
Thank you Nina and Dane (Great Looking Fish from Lake Mohawk)
Fishing - The ideal fishing lake consists of approximately 35% aquatic macrophytes (plants). The graph below shows the relationship between the amount of aquatic plant cover and the largemouth bass/sunfish population in a lake. As the graph indicates, when plant cover becomes less than 35%, the relative fish production of both sunfish and bass declines. Conversely, as plant cover increases above 35%, the largemouth bass population declines while the sunfish population increases. In summary, aquatic plant cover to some degree is required to maintain a healthy fisheries.
Please submit your fishing photos for publication to this website.
"I prefer to have fewer aquatic plants" (Boaters, Skiers, Tubing, Etc.) vs. "I prefer to have more aquatic plants" (fishermen) vs.
This section is for the purpose of bringing the Lake Mohawk Community together for the common good of all individuals. Property values, personal health, and recreational activities (boating, skiing, fishing, wakeboarding, tubing, etc) ALL depend on having a WELL BALANCED LAKE. Hopefully, this section will enlighten you on the value of sound lake management.
I prefer fewer aquatic plants
Too many aquatic plants destroy the recreational value of a lake, especially from a skier's or boater's point of view. Also, there are many exotic species of plants such as Eurasian watermilfoil that should not be allowed to dominate or expand as part of the aquatic plant population. It is completely understandable why a skier or anyone having water contact with the lake water would not like aquatic plants. Certain species of aquatic plants become entangled in propellers, jet ski intakes, as well as around the arms and legs of those skiing and tubing.
Selective aquatic plant control is the key to managing aquatic plants to a level which may be acceptable to most recreational users of the lake such as skiers, tubing, etc.. .
WE ALL KNOW ABOUT BLUE-GREEN ALGAE AFTER OUR EXPERIENCE IN 2009.
West Beach July 2009
Blue-Green algae as we know can close down a lake due to the toxins they can produce. BENEFICIAL PLANTS help naturally control blue-green algae by
1) Stabilizing sediments (remember sedimentary re-suspension of phosphorus) 2) Competing for nutrients such as phosphorus 3) Secreting inhibitory chemicals against blue-green algae (more study needed in this area)
BENEFICIAL LOW GROWING plants also crowd out many tall and undesirable plants such as Curlyleaf Pondweed, Milfoil, etc..
Finally, plants established in near shore (30-40ft or less) areas provide excellent wave buffers that not only stabilize shorelines to prevent shoreline erosion, but also to prevent waves from regenerating back into the middle of ski zones. Those homeowners that have "swim zones" in front of their homes, can have those plants selectively controlled within their property area. If you have a special request to eliminate the aquatic vegetation in front of your home, simply e-mail or call me at your convenience leaving your lot number and special request.
In summary, it is important to understand that some species of aquatic plants will help us have a better recreational summer. As individuals that prefer less aquatic vegetation, we can expect to control the less desirable species of plants out of our "recreational" zones.
I prefer more aquatic plants (Fishermen)
Aquatic plants play an integral role in a healthy fisheries. Studies have shown that a lake should have 35-40% vegetative cover for for an optimum bass population.
Too many aquatic plants can stunt fish growth, cause summer fish kills, cause winter fish kills, and pretty much make it impossible to go fishing even with those 150 HP motors.
Just as with those individuals that prefer less aquatic plants, Blue-Green algae can adversely affect you also. Blue-green algae secretes toxins which can be directly toxic to the fish or to the fish flesh that you may consume. Blue-Green algae also starts to kill rooted aquatic vegetation by limiting the light to those plants.
Many of the plants that are NOT desirable for fishing are the SAME plants that are NOT desirable for skiers, boaters, etc.. So......when we control the undesirable species of aquatic plants at Lake Mohawk, please do NOT think that we are killing all the aquatic plants in the lake.
More specifically, we are trying to control MOST (NOT ALL) of the Curlyleaf Pondweed as well as the Eurasian watermilfoil. We are trying to maintain much of the Naiad in addition to the advanced form of algae known as Nitella and Chara. Nitella / Chara is now making a "strong" presence in the lake. While most people will mistake this growth for an aquatic plant, it is actually an advanced form of algae.
Okay...now for the little microscopic organisms in the water. We want to control the blue-green algae while maintaining the "green algae" (yes...there is a difference). The green algae are the "good algae" (most of them) and are less susceptible than blue-green algae to copper. Our blue-green management strategy therefore is to treat with low doses of copper ONLY WHEN NECESSARY so we don't kill the green algae OR the Nitella mentioned above.
I do not use the lake
Believe it or not, there are a number of people that do not use the lake at Lake Mohawk. For this group of individuals, the most important feature of the lake is how it may affect their property values.
A WELL BALANCED LAKE is like "money in the bank". Too much copper on the bottom of a lake has the potential to destroy the ecology of the lake as well as the property values of homes......not to mention what we are leaving our family, friends, and lifelong residents, children, and following generation of young adults.
Alternatively, allowing the lake to go "completely natural" also has the potential to ruin property values, impair recreation, and adversely affect our health.
The answer; become involved, have patience, educate yourself, and work with the individuals that are trying to make your Lake Community a better place to live.......NOT only for Today....BUT for Tomorrow as well.
BATHYMETRIC (Depth) MAP of Lake Mohawk 2010
Click on Map to see larger version
Depth and GPS data were collected on June 17th, 2010 for the purpose of producing a bottom contour depth map (Bathymetric Map). 6GB of data has been compiled to reveal the underwater landscape of Lake Mohawk. This type of map is useful in planning for sediment removal, determining the effectiveness of sediment removal (checking the work of the contractor), water volume and average depth determinations,
Click HERE to see the current underwater map of Lake Mohawk
2010 Lake Mohawk Report Please click on the button below to download the report in PDF format
Please click the "button" below to download report in PDF format
Copyright 2011 Grays' Aquatic Services Jeff Gray
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2012 Rainfall & Lake Level Data
Monitored & Provided by Eric Howland Lake Conservation Board Member
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