Water Clarity - why not so clear

[bwana_d]

Anyone know what makes a lake cloudy one year and perfectly clear the next?

Most of time I can make out small (almost microscopic) white organisms in the water. If I look really close they twitch. Some years they seem to get larger and fewer as the season progresses and the water gets clearer.

I have had a few theories but not sure if any are tied to it or not:

• How soon after turn over the freeze up actually occurs
• Amount of wind preceding freeze up
• Drought cycles
• Lack of forage base eating the little bugs I see

[Gordie]

I have seen the same thing from one year to another on certain lakes and I think it depends on the wind before freeze up and lately how long it takes to freeze up.

I have noticed that on a certain lake I frequent that it usually starts out clear then clouds up as the season goes and this is due to a warming trend after freeze up. it lets the run off from the roads and creeks enter this body of water and then it seems to cloud up.

As for the bugs and stuff the less time the snow is on the ice the more active those little bugs will be, due to more sun reacihing the weeds in the water, which in turn causes the weeds produce O2. I guess this to could casue some problems with water clarity or it could also help lear up some waters.

Great question

[Gissert]

I think the wind prior to capping over is the biggest factor. I live on a lake, and I do the secci monitoring for the MPCA on it. This fall I had readings of 20-22 feet after turnover.

Last year I could see the bottom easily in 14-16 feet. This year, I can barely see down six feet.

We had very strong winds, and then it froze up partially, and then the wind pounded it again and broke most of it up. It calmed down and it capped over and it has been cloudy ever since. The lake never got a chance to breathe (for lack of a better term) prior to freezing up.

[mrklean]

I have noticed water quality has been poor this year compared to last year on a few metro lakes

[Spike76]

Old timers used to talk about the lakes turning over. I think when it gradually gets cold, the warmer water at the bottom rises slower and the colder water right under the ice, goes lower. I think that when it gets colder faster that sometimes it turns over faster and stirs up the bottom. This might not make sense , but it's what I blame the poor visibility on. Remember I'm old.

[Bowfin]

I've noticed murkey water when the winds are high even after the lakes freeze over. I think before the ice gets too thick wind can push down on the ice creating a subtle suction effect drawing up some sediments from the bottom.

[Gordie]

Today I watched the water turn from almost clear to murky in an hours time and I think some part of it was due to the fact that the sun dipped behind the clouds today.

I still had plenty of fish in the hole but most of them were the wrong speices.

[BOUNCED]

Today I watched the water turn from almost clear to murky in an hours time

Sounds like bottom feeders, I've seen carp make a real mess of things

[Meat-Run]

When in college I used to spear on Lake Bemidji, while spearing up on a shallow sand flat I noticed at the beginning of a major front I could actually see the sand/silt stir up the bottom and cloud the water a bit. The ice wasnt thick and moved up and down from the wind and caused it to actually push down the ice causing the bottom content to lift off the bottom.

Meat Run