LAKE TURNOVER?

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lobinero
Posts: 36
Joined: Wed Apr 13, 2011 7:51 pm

LAKE TURNOVER?

Post by lobinero »

Lately, there has been a lot of conversation regarding lakes which surface temp has not dipped under 53 and the fall turnover. Taking for example lake New Melones with an actual 53-55 temp. Back in November into December all the shad could be found in depths of 40-60 feet. Along with the predators too, bass. I would think that this is a sign of a turnover if forage and predators can survive at such depth when in the Summer they were above a clear thermocline! Also now bass can be found at any depth 50-0, thus proving that the oxygenation is all through out the water column. I'm not a biologist, but imho it seems that the lake turnover.
I would like to hear from a marine biologist to clear this based on experience and expertise.
WRB
Posts: 1069
Joined: Tue Dec 29, 2015 8:47 pm
Location: Simi Valley

Re: LAKE TURNOVER?

Post by WRB »

Lakes that don't freeze may have 1 fall turnover when the summer warm surface water cools rapidly from 75-85 degrees to 70-60 degrees as ball park temps. Cold water is heavier then warm water and sinks. When the water column approaches equilibrium the lake turns over brings bottom decayed debris smelling like sulphur to the surface mixing the entire water column to equal temps.
It takes about about 2 weeks for the eccosystem to settle down, the dissolved oxygen levels and water temps are the same top to bottom with the surface continuing to cool and mixing with windy conditions until the cold water winter period. All the fish can be wherever the prey sources are located. Deep water is warmed a few degrees by the earths heat about a constant 60 degrees so bass being warm water fish prefer the warmest water they can find and that is usually deeper water.
If a lake has a aeration system that tends to keep a thermocline form developing along with reserviors used for power generation creating current that can mix the thermocline. It's a myth that bass will not go below a thermocline because of low DO levels, they do if prey source is deeper but tend to aviod any water temp change of the 10 degrees.
The water is now warming, the bass will moving up to pre spawn bass fishing only gets better.
Hope that helps,
Tom
PS, I am not a marine biologist only a bass angler with lots of experience. Lookup thermoclines and educate yourself.
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