Thermocline And Catfish?

Discussion in 'LOCAL KENTUCKY TALK' started by Marshall, Jun 29, 2008.

  1. Marshall

    Marshall New Member

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    124
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    Junction City,
    I was wondering how to determine a lakes thermocline. Or is it possible to determine it? Does it also have effects on catfish? Just trying to gain a little more knowledge. Hopefully someone can help.
    Thanks
    Marshall
     
  2. AwShucks

    AwShucks New Member

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    Guthrie, Oklaho

  3. dougc

    dougc Active Member

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    A good depthfinder will show the thermocline.
     
  4. Marshall

    Marshall New Member

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    124
    State:
    Junction City,
    Thanks For the info Guys. It helped me alot. Next Time Im out on the lake Im gonna try to figure this thing out on my depthfinder. I have a 747C HumminBird, that i bought last year. It should show it on there I would think. I also searched the Humminbird website and got the following info:
    Ensure the unit is in Sonar Mode. Increase the sensitivity to view a weaker sonar reflection from the thermocline. It has to be a large enough difference and change quickly enough vertically to display as a thermocline or it will not reflect the sonar signals. Since the density of the water changes with it's temperature, the sonar signal will reflect off the change in water density. The change in water density creates thermocline (temperature in water must be drastic enough to change the sonar signal). Again Thanks for the info Guys.
     
  5. jeremiad

    jeremiad Well-Known Member

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    A more direct link to the article referenced by Lawrence is http://www.sportsmansguide.com/article/article_read.asp?aid=158644&sid=18. This link will keep you from going by way of Hungary (.hu). :wink:

    I would not expect catfish to be that concerned about thermocline since they tend to be bottom feeders. Catfish are also less impacted by variations in oxygen levels, being more tolerant than game fish, such that thermocline is not as critical.

    On the other hand, catfish gotta eat, so they will have to follow their food; I figure that they'll emerge from the depths to snatch 'em from underneath though (can you hear the Jaws theme?).

    Perhaps they move upslope/downslope based on temperature, though, so I could stand corrected.
     
  6. Marshall

    Marshall New Member

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    124
    State:
    Junction City,
    Thats very interesting thought you brought up there. Maybe will get some more knowledge from these great people on here. Thanks for the great reply jeremiad.
     
  7. AwShucks

    AwShucks New Member

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    4,532
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    Guthrie, Oklaho
    I have always heard that the water below the thermocline is water with low/weak oxygen and fish can visit the area but cannot remain there as they will die. It's like setting a trotline in water that slopes from shallow to deep. On the shallow end, your fish will be alive whereas on the deep end they will normally be dead, especially if the line crosses through the thermocline. The best bet is to determine where the thermocline is at, then search for structure near that depth. And it will change, day by day, so you need to change your locations accordingly.

    My thanks to Joel for correcting the link. LOL
     
  8. Marshall

    Marshall New Member

    Messages:
    124
    State:
    Junction City,
    Thanks for the info AwShucks. So are you saying all fish maybe able to drop below the thermocline or just catfish? Maybe they smell the food/bait below the thermocline drop down and gobble it up and get back above the thermocline. That sounds very possible. Especially with cats. I wonder how far under the thermocline they can go then? I am fishing Herrington Lake where the max depth is close to 300 feet at the dam and by mid-lake the depths already pushing 150ft. There is a ton of structure in the lake, so say i am fishing 40ft of water and the thermocline is at 20ft will a cat be able to make it down to the bottom and take my bait or would i be better off useing a slip rig around the depth of the thermocline? Hope you guys dont get tired of my ongoing questions and thoughts. lol. Just tryin to get more educated. Thanks again for all the info guys.
     
  9. jeremiad

    jeremiad Well-Known Member

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    One thing to remember is that not all lakes stratify, and therefore do not exhibit a thermocline. This usually is due to strong, deep currents that mix the water fairly well, but can also be due to lake orientation, wind effects, and so forth. Many of these lakes are often riverine, being deep sided, often found in mountainous regions. These lakes often support two-story fisheries: warmwater game fish and trout. Virginia, for instance, provides such great information on in-state lakes that they will tell you if a lake stratifies or not. Some lakes stratify but do not turn over, whereas some lakes turn over several times a year.

    Further research on my part confirms that catfish will follow the thermocline due to a need for adequate oxygen levels. In summer, they will tend to enter deep water during the day to remain cool, or find shaded or well-structured areas in shallow water. At night they will move back into shallow water where oxygen levels are higher.

    By the way, there is a great resource on the Web for understanding lake stratification: http://waterontheweb.org/curricula/bs/teacher/thermal/teaching.html

    An interesting side note is that scuba divers can actually see the thermocline during the heat of summer. Known as schlieren, this appearance of wrinkled glass at depth is very similar to the water-like mirage of heat waves rising from hot asphalt.
     
  10. lance

    lance New Member

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    2,658
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    A guess would be if your seeing baitfish you would find cats= thermocline? Baitfish would have less tolerance to low o2 levels? Im guessing some interesting knowladge on this post :roll_eyes:
     
  11. CatSkinner

    CatSkinner New Member

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    State:
    Paducah, KY
    I SCUBA and can attest to being able to see the thermocline. It's particularly neat to see when there is a fine layer of "dust" (fine sediment) sitting on it.
     
  12. brother hilljack

    brother hilljack New Member

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    that really sounds like some very good info. Thanks for the valuable post. This type of effort is what makes the boc so valuable
     
  13. Marshall

    Marshall New Member

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    I agree with you, Brother Hilljack. There is no where else you could learn the knowledge you do on this site. Except maybe the lake or river the hard way.lol All these guys that take time to answer these posts are just incrediable. I appreciate all the tips and knowledge you guys share. Thank You All! Marshall
     
  14. kyredneck

    kyredneck New Member

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    1,021
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    Kentucky

    Joel, because they seem to live longer than most fish out of the water and the fact that they are generally bottom feeders, it’s easy to assume that catfish would be less affected by O2 levels than other fish. From my experience it’s quite the opposite.

    In 1988, a combination of drought, excessive geese & duck droppings, and being overstocked with channels & hybrid bluegill, caused a small pond on my place to literally turn black & septic suddenly overnight. The next morning the surface of the pond was littered with the whites of dead, floating, belly-up catfish, but the bluegill were still alive and coming to the surface to breathe. This septic condition persisted for weeks and the bluegill never stopped coming to the surface to breathe. I was amazed, not a bluegill died during this time and the pond later became a bluegill hotspot for the kids. Also it’s been my experience that fish such as red horse or buffalo suckers survive on a trotline while catfish die in stagnant water conditions such as drought or the dog days of summer (that’s when I quit fishing the trotline).

    Contrary to mainstream thought I’m of the opinion, from my experience, that thermoclines form not only in lakes and reservoirs but also form under the right conditions in lock & dam rivers such as I fish. I’m also of the opinion that when this stratification occurs, bottom feeders such as suckers or catfish will spend most of their time in the higher O2 levels of the thermocline and will go to the bottom in search for food, but cannot stay there long and must return to the thermocline in order to have sufficient oxygen to live.

    Just my two cents worth.
     
  15. jeremiad

    jeremiad Well-Known Member

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    Reps to you Larry for some great information!