Northwest Fishing Reports

any truth to the colder VS warmer water in a lake rolling over at certain times of the year? i was out at silver yesterday and got told it was prolly flipping...thus the reason nobody caught any fish...

My favorite lake flipped twice a year before summer and before winter. When the lake flipped the time before summer I knew it would be time to chase bass after water cleared:cheers: It is very common but I do not know about Silver. And when the lake I fished flipped it was hard to catch fish off the bottom#-o

Every lake is different, but many do have a turn-over or flip event.

Water is denser or heavier at 39 degrees then at any other temperature. Below that temperature it becomes less dense, until it is frozen at 32 degrees, where it is the least dense and floats on other water. Above 39 degrees the water becomes progressively less dense until it boils.

So, normally in the late fall, the cold water created at the surface builds up and the starts to fall to the bottom of the lake where it displaces warmer water. As the displacement takes place, the lake "turns over".

Many claim that their favorite body of water also "turns over" in the spring, but to be totally honest with you, I can't quite buy it for most bodies of water.. From a purely scientific point of view, how does a cold body of water, a body that warms on top, turn less dense warm water over to the bottom?

I suppose, back to the "every lake is different", that if you have a cold run-off (39 degree or less) entering a warmer then 39 degree body of water, that this could create a turn-over, but few bodies of water that I know do this. You could also have a prolonged high wind that forces the water to one side, causing a temporary turn-over; I have seen this once.

What I suspect is happening is that as the algae starts to grow on the bottom of the lake that it gets to a critical point and it suddenly floats to the top. To the untrained eye, this looks just like a "turn-over", but in fact, the water itself did not turn-over at all. This type of event can and does happen a lot on many lakes and ponds, and it can happen multiple times as different types of algae get sufficient light and warmth to grow, bloom, float to the top, die, sink, then start the next again with the next species.

It matters not if the event is a true turn-over, or the fake algae bloom turn-over, it can and often does impact fishing for a a few days as the fish and bait re-establish patterns and get use to conditions.

I don't know much about turnover but Silver held a 2 day ABA bass tournament Saturday and Sunday and it got whacked. I would say that proabaly had more to do with it than the color as it was very off color for the tournament also and they still caught them pretty good.

thanks...gonna hit ohop in the morning...

I live in the Spokane and the area lakes around here show a strong Thermocline which is a "striation" of temperatures within the lake. In the late spring and summer months the lake's water warms at the surface down to about 10' or so from the solar radiation. Even on the brightest days the solar radiation won't warm the water below 10'. So with that the top of a lake can warm to nearly 80° on the shallower lakes and into the high 70° on most others while the lower part of the lake will stay near the mean earth temperature or about 58° to maybe 55°. If the body of water stays mostly calm the two water masses don't readily mix except for a 5' or so transitional layer.

As a mainly trout fisherman I use a thermometer with a 20' lead on it to locate the depth of the Thermocline or transition layer to locate where the trout are "holding" as water above 70° holds too little O2 for the trout. For the "warm water species" (Bass etc.) the lower O2 levels aren't as much of an issue. Trout will move through the warm water for food, but will return to the Thermocline to hold.

Here is a better explanation http://en.wikipedia.org/wiki/Thermocline

Tight Lines!

Marc Martyn wrote:

http://www.washingtonlakes.com/ReadArticle.aspx?id=300

And an even better one here!!!

good stuff!!! thanks... i learn more every time i visit this site...

That's the idea, have fun and learn things from others. :thumright

one thing I noticed that the large mats of algae hold a lot of trapped gas and this probably why they float to the surface. The decomposing materials in the lake bed give off methane and also sometimes other gases...the "much" at the bottom traps these gases and eventually float to the surface but since they still retain the gas even at the surface, they stay afloat....Im mostly speculating here....

ruthven78 wrote:one thing I noticed that the large mats of algae hold a lot of trapped gas and this probably why they float to the surface. The decomposing materials in the lake bed give off methane and also sometimes other gases...the "much" at the bottom traps these gases and eventually float to the surface but since they still retain the gas even at the surface, they stay afloat....Im mostly speculating here....

I qute agree, and as the algae gets to the surface it will either mat over (can you say rat time for BASS), or it will get too warm and die, decay, then sink.