Does a water ski boat improve the water quality of a lake?

[ecstaski]

We are trying to get access to an expired quarry that has a 2200 foot by 500 foot lake that is 10 to 20 feet deep as a water skiing site. There is no water course in or out so the lake is stagnant feed by rain and possibly ground water. The lake is 60 feet below ground level so it is very well protected from the wind. The property is owned by a conservation authority that wants to develop the lake for fish. I am arguing that a water ski boat will substantially increase the oxygen levels and contribute to mixing the water which will increase the lake's capacity for fish. The theory is that during warm weather months, pond water stratifies into three layers. The top layer is warmer and contains oxygen producing algae. There will be minimal wind action on the water to mix and contribute oxygen to the top layer. Due to the fact that there is no water movement. as you go down in the water the water will cool down. There will be a middle layer which will be a relatively thin layer characterized by a rapid drop in temperature and oxygen levels. The bottom layer will be stagnant, cool water, with little or no oxygen. It does not mix with the upper level during warm weather. The fish habitat would be limited to the top layer. Therefore the propeller action of the boat will not only add oxygen to the water but will substantially contribute to mixing the layers providing more oxygen to a greater depth and creating a greatly improved habitat for fish.

 

Does anybody have information or knowledge of studies or papers that would substantiate this argument?

Do you know of any other arguments that could be presented to justify that a water ski tow boat would improve water quality?

 

 

[Horton]

boats and skiers = O2 in the water and that is good for the lake.

 

 

[SkiJay]

@ectaski This isn't scientific, but we have two lakes that are side by side, joined at one end, and fed from a common water source. They are virtually identical in every way except one. One lake has the constant boat traffic of a ski school, the other is private and sees about 90% less skiing traffic.

 

Any time there is an issue with algae, it always shows up in the private lake first, and sometimes not at all in the busier lake.

 

I totally agree with your position, and good luck!

[crashman]

Same as OB i dont have studies but I looked at a former pit ski lake last year as a potential purchase. Similar dimensions to the one you're looking at. At one point there were multiple tournament skiers who would train there and they gradually moved to other lakes. They took the course out several years ago due to non- use. The fishermen on the lake all agreed the water quality was much better when the skiers were there.

[rawly]

One of our neighboring ski lakes is also a catfish farm. The most use the lake gets is from the skier/farmer who runs his boat up and down the lake to help the fish stay alive when the conditions would otherwise kill them. PM your contact info if you would like to speak with this guy.Good luck with securing the sight.

[bishop8950]

I believe the boat activity helps for all the reasons above. Another way to come at this is that there are plenty of examples of ski lakes serving as fish ponds with great success. Worste case impact seems indifferent and the info above suggests symbiotic.

 

The site sounds great and I hope you snag it

[DanE]

@ecstaski‌ http://iof3.idrottonline.se/ImageVaultFiles/id_60284/cf_104/IWWF_Env.PDF

[malibuowner]

Not scientific but when we first tried skiing our lake it was totally choked off with milfoil. It was so bad we couldn't put a course in. We decided to put our course in early the next year before the milfoil bloomed for the summer. We put the course in and started skiing. Never had a problem with milfoil again. We have been skiing this lake for several years now and water quality is way better.

[Dusty]

Every ski lake I've been to has more creatures in and around the water than other ponds not being skied on. Can't even think of an exception.

[PatM]

A water treatment expert (also a former water skier) confirmed to me a long time ago when I was putting in our course that water skiing (boating) introduces needed oxygen to the water.

[boarditup]

Yes, ski boat traffic makes a dramatic improvement in water quality. Boat traffic in general will improve water quality and oxygen saturation to a level of about 4-6 feet deep. Ski boats, with inboard propulsion, mix the water deeper - to about 8-10 feet. Heavily loaded wakesurfing and wakeboarding boats will mix the water to a depth of 15-feet. The most important attribute for mixing is the start-up, not the surface running. Slalom is the best normal watersports activity for mixing since it requires a startup at each end of the course and sometimes in the middle - when recovering a faller skier.

 

The net effect of the ski, wakesurf, and wakeboarding boats is dramatically increased oxygen content to much more significant depths than in a still lake. For a well wind-protected lake, this can be the difference between a fish kill and a viable community of fish. Fishing from a boat does not give nearly the benefits of the towed watersports boats because they do not have the physical layout to mix water at a significat depth nor do they have sufficient number of full-throttle starts to provide any effective water mixing at depths greater than 3-4 feet.

 

Running towed watersports boats will also dramatically improve the nutrient loading of the lake. The BOD, the Biological Oxygen Demand, will be significantly reduced. This is due to the ability of fish and other species to use the plant matter as food as they have increase oxygen to survive. It is important to have the boating activity fairly consistent during the warmest months, June-September, to avoid the dramatic stratification of the lake water. If this is done, by having sufficient structred events, the fish population will have a visible and dramatic increase in 3-5 years. Once the towed watersports activity is shut down, there will be a fish kill in about a month of intense summer heat.

 

There is a way to artifically induce the oxygen into the water without boats. It involves piping air through diffusers placed on the bottom of the lake. Typical density is one per 20,000 surface square feet of water. This is expensive to run and a maintenance nightmare. You will find these systems in fish farms nationwide, where skiing is not used to oxygenate the water. You will find several fish farms use skiers to oxygenate the water and avoid the expense of the air diffuser system.

 

I hope this helps.

 

Good luck.

[ecstaski]

Thank you all for your comments - I actually found a document in the Google Books library that is a NERC reviewed and approved study done in Winter Park Florida in 1974 that supports the theory. It actually documents Boarditups comments. The adverse effect is turbidity but it also indicates that this only occurs in water less than 6 feet deep as well as from shore erosion. For any of you that might also find it helpful as a resource, this document is free from Google Books at this link; http://books.google.ca/books?id=nmwYAQAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

[thager]

I am so old I remember that report.

[sltrju]

I was a member a ski club that leased one of numerous lakes. We were told that the lake was available because it had less fish. A couple of years later we were asked to change lakes as the lake we used now had more fish than most of the other lakes.

[A_B]

Most EPA and Government studies say no wake zones for controlling how much sediment is churned up, so I would stay away from those types of research. They don't site the long term benefits of sediment filtering other things to the bottom. The IWSA put this out:

 

http://www.iwsf.com/EnvironmentalHandbook/iwsfecpartb.htm

 

I have owned a lake for 30 years. Within the last 10 years, our water has become crazy clear at the ends of the season. Easily seeing 6 feet to the bottom around the shoreline. It was not like that at all when we bought it, and it was just a borrow pit with no traffic. The fish population has also done very well.