fish kill

Looks like quite a few cats and other less desirable species have died in the heat around here fish kills

Bummer.

I remember, back in about 1988 I think, there was a serious drought here in Iowa. The result was a lot of the local lakes with BIG fish kills. Water was low but more importantly, the water was hot. There were a number of lakes that lost all of the stocked walleyes and muskies, most bass and panfish suffered too. Some of those lakes were never restocked with walleyes or muskies. I’m not sure how the catfish faired…they never get much attention.

Hope it cools off soon. Supposed to be hot (100+) the rest of the week here…and dry, dry, dry. I’ll be watering my garden daily for a while.

This has been a weird year weatherwise so far…wonder what December/January will bring.

L8R…Ken

From the article:

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“As water temperatures go up, water is not able to hold as much oxygen, which fish need,” said Scot Stewart, DNR south central district fisheries supervisor, in a statement. “Respiration by plants can reduce the amount of oxygen to levels lethal to fish. That’s when summer fish kills occur.”

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Now, is it just my ignorance, or don’t plants consume carbon dioxide and produce free oxygen into whatever medium in which they may be growing?

That is to say that “respiration by plants” SHOULD be increasing the available oxygen in the water.

Then again I’m neither a biologist nor do I work for the DNR. And it’s possible that my 3rd grade teacher was a crackhead.

Sheesh! (unless there’s something I don’t know, then scratch the SHEESH! part)

Plants still respire at night, that’s where the O2 drain comes from.

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Plants still respire at night, that’s where the O2 drain comes from.

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That’s what I was going to say. You beat me to it.

Quote:

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From the article:

Quote:

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“As water temperatures go up, water is not able to hold as much oxygen, which fish need,” said Scot Stewart, DNR south central district fisheries supervisor, in a statement. “Respiration by plants can reduce the amount of oxygen to levels lethal to fish. That’s when summer fish kills occur.”

---

Now, is it just my ignorance, or don’t plants consume carbon dioxide and produce free oxygen into whatever medium in which they may be growing?

That is to say that “respiration by plants” SHOULD be increasing the available oxygen in the water.

Then again I’m neither a biologist nor do I work for the DNR. And it’s possible that my 3rd grade teacher was a crackhead.

Sheesh! (unless there’s something I don’t know, then scratch the SHEESH! part)

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It’s more of a physics thing than biology.. There’s a certain temperature range in which water holds oxygen well.. Too warm and you “boil” the oxygen out of water.

About 23C/75F is when the oxygen levels start to noticeably drop. So you could have an underwater forest cranking out oxygen, but the water isn’t going to hold it like it would if it were say, 60 degrees.

With our high temps here in Iowa, I decided to jump in and dive down to see how cold the water is ..water temps were in the mid 80’s but after diving down to about 10ft. the water got so cold I had to come back up.
Water was too dirty to see where the fishes were hiding

Yeah I never can figure out why on a river the water doesn’t have a more uniform temperature top to bottom. You’d think the current would keep it mixed well, but it must not.