Cool weather

[MOfishmgr]

I've been getting a lot of questions about the cooler summer and how it affects fish. Mostly it's been bass anglers, but the same situation impacts crappie too. What happens when the water is slow to warm to summer temps (it was 78 degrees at Smithville today) is that naturally ocurring bacteria are having a field day with the fish. Bacteria reproduce best when ater temps are in the 70's. For healthy fish this is a minor nuisance but it can impact their feeding, i.e. they don't bite as well. Last year at Smithville we had a pretty good die-off of old slow-growing black crappie when this happened. It was casued by bacteria and only impacted slow-growing fish. I aged a sample of the dead ones and they were all 7 to 8 years old, ancient for crappie. We may see the same again this year.

Think of it as an extended post-spawn period. As soon as the water temp get above 80, the bacteria reproduces so fast it burns itself out and the fish will go on a feeding binge. With the forecast highs for the next few days we should see water temps go up and the fishing should be really good the next couple weeks.

Good luck this weekend.

[shockley32]

That's very interesting. Keep the good info coming.

Thanks,

Brad

[APKape]

Good to know. I did see a few dead crappies floating up by the Roberts Branch area.

[camo_boat]

thanks for the info!

[camo_boat]

i have a question that i have long wondered and hopefully you may be able to help; how many crappie do you guess are in Truman???

[jackb]

NONE! Monty and Ron, and the jj's caught them all.

[bwillaub]

i have a question that i have long wondered and hopefully you may be able to help; how many crappie do you guess are in Truman???

I have wondered that myself from time to time. Do they count them per acre like they do deer?

[MOfishmgr]

Good question! It's impossible to tell. That's the big challenge for us biologists. We collect samples of the population to determine the size distibution and age and growth info. From that data we can make inferences about the overall condition of the population, but the actual number of a particular species is difficult to obtain. In the past biologists would use nets and block off a small cove and kill every fish in it to make those estimates. That's rarely done anymore. Most fish are collected with electrofishing or netting. Electrofishing let's us collect large numbers of fish in a short amount of time. I have shocked up to 1000 fish an hour! We typically monitor crappie populations in the fall with trapnets. These are box framed nets with a lead that is attached to the bank. fish swim into the lead and then follow it to the net where they are trapped. A good net will yeild 100+ fish per 24 hour period. Unlike fishermen we are often more concerned with young, small fish. These give us an idea how many were produced relative to past years and help us make predictions for upcoming years.

There are instances where we can get actual popualtion estimates using multiple electrofishing trips. This is usually only done with bass. we fin clip each abss caught and keep track of how many marked vs. unmarked fish are caught on subsequent trips. These numbers are plugged into a computer program which spits out an estimate of the total number of bass per acre. An over abundant population will hve more than 50 bass, 8" or larger per acre. We try to keep the numbers at 30 to 50 bass per acre.

While elctrofishing is effective it has it's limitations. We can only shock effectively when fish are in the shallows, which means while you guys are hitting the spawning fish with rods and reels, w are busy collecting data. I use spring electrofishing for crappie to help determine what's there for anglers to catch right then. I post that info here and in fishing reports.

Hope this helps. In general the more fish you have the slower they grow. When crappie are reaching at least 9 inches by age 3 we consider the popualtion to be about right.

[bwillaub]

That's some good info. Thanks for your efforts. The fishing has been fantastic on Truman this Spring and thus far this Summer. Can't wait to see what the Fall and Winter have in store.

[got crappie]

Jake fishing has been real good at Smithville also keep up the good work. Dave