Lake Zumbro

Sure would like to know what killed em off.

http://www.kttc.com/Global/story.asp?S=12873711

http://www.postbulletin.com/newsmanager/templates/localnews_story.asp?z=2&a=462750

Could you past the story here? I can’t open links at times.

I can’t open the KTTC one here at work, but it has video. Heres the Post Bulletin article.

ORONOCO — Several hundred channel catfish, some weighing up to 10 pounds, were found dead in Lake Zumbro over the weekend.

The Department of Natural Resources received several calls about it on Monday and sent a crew to investigate, said Kevin Stauffer, area DNR fisheries supervisor.

Because the fish were badly decomposed, the officials couldn’t get any fish to send to St. Paul for toxicological studies, he said. The DNR will send out another crew on Tuesday, he said, hoping to find fish that can be studied.

Because only channel catfish were found dead, it would appear they were killed by some kind of disease specific to them, he said.

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Could you past the story here? I can’t open links at times.

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I had already posted it in SE Mn forum.. but here is is again.this is from news channel.

Hundreds of dead catfish filling Lake Zumbro

LAKE ZUMBRO (KTTC-DT)– Hundreds of dead catfish are washing up along the shores of Lake Zumbro and the Department of Natural Resources doesn’t know why. The carcases of the channel catfish can be seen floating along the banks of the lake, some of them weighing up to 12lbs.

“We’ve had fish kill before but this is the first I’ve seen the CatFish and especially this many,” says Tom Swenke.

There are so many rotting Fish carcases filling the lake that the DNR was called in to investigate Monday morning.

“They’re washing up all over the lake, heading down stream with the current,” said Swenke who lives near the lake.

Officials spent the day collecting the channel CatFish, which can be seen floating just about anywhere on the lake.

“By the looks of them and what we’ve heard, it might be a fungus that’s killing of some of the breeds here in the lake,” Swenke notes.

While all of the dead fish are unsightly to look at, the worst part, residents say, is the smell. The DNR hopes to have some initial tests complete, by Tuesday morning

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I had already posted it in SE Mn forum.. but here is is again.this is from news channel.

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Thanks, and sorry trumar, I guess I need to get out of the Cat forum more often.

its ok, I should have posted here,not much action over in the SE Mn forum

BP?

Sounds like there was an awesome fishery for channels in Zumbro.

I think Dan T. is the only one that reports on them.

I always knew that the Dark30 lick was gonna affect them fish sooner or later. That or Tyler Holm was kissin them before release. Kiss of death ya know?

I just got to thinking. The channel cat bite the last two-three years has been awesome. Rarely a skunk and double digits quite often. So maybe there was just too many? Maybe this is some kind of natural population control? Lets just hope that the majority of them escaped whatever mojo that affected the kill.

That’s what I was thinking too. Seldom does a disease take hold when populations are thin.

PS Thanks for reminding me not to kiss Tyler.

A little natural selection or selective harvest to cull out the over population. Nothing wrong with that except the next population explosion will be skunks and raccoons eating the new bounty.

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BP?

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Roughe walleyes?

Probably turn out to be something dumped into the lake to kill that many fish at one time.
Natural kills usally occur over a extended time period.

Yeah, with a big quick kill, it would seem to have to be an ‘acute’ thing, like a spill or something introduced to the lake. Otherwise you’d think it would kill the smaller ones first, then the 12lbers sometime down the road..

Any idea on how long it takes a fish to decompose? Maybe they floated down from up river? I wonder, was it an all at once type of thing or did it take a few days to get them all?

Not all disease die offs occur over a long period of time.

Normally diseases will distress a lot of fish and then it will take something like low oxygen or rapid temperature changes and the go belly up in mass. No one really notices when they are dieing off one at a time. Add a second trigger that causes them to die in masses and people take notice.

Since it is only affecting catfish, I’d still suspect disease. Something being dumped in would be non discriminant and killed off many species.

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Any idea on how long it takes a fish to decompose?

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In the right water temps (warm 80-90F) a dead fish can turn to an unidentifiable mass of mush in 24hrs.

This sudden, “one-time” event that only impacted cats appears to be some disease to me. It will be interesting to see what the tox tests find.

Yeah, my money’s on an infectious disease of some sort, either in the cats themselves or in some aspect of their food chain that indirectly affected them. It could be a spill of some sort of toxic-yet-attractive food item, like cats and ethylene glycol, but to get that many fish it’d have to have been a HUGE spill.

Bacterial and viral infections can spread like wildfire. Fungal infections are usually a slow-burn and take a long time to have a broad impact, although when it does show up it can be devastating.

I’ll be interested to hear the results of their testing.

Copied from Tyler Holms post on R.O. an email from the fisheries dept.

– Lake City Fisheries first received reports of dead channel cats on Monday, July 26. Lake residents and anglers reported observing large numbers of dead channel catfish along the shoreline. Several also said that they had seen catfish swimming slowly in shallow water during daylight hours, which is obviously not a normal behavior for this species. A fungus like growth was visible on the dorsal surface of the affected catfish.

– We sent a crew to Lake Zumbro later on Monday morning and they confirmed reports we had received. They did counts in a number of shoreline areas and observed dead channel catfish on most areas of the lake. Estimate of the number of dead channel catfish from Monday’s reconnaissance: We sampled approximately 1/3 of shoreline (21,000 feet or so of 61,000) and counted 168 dead CCF. This extrapolates to an estimate of approximately 500 dead observed on shorelines only. This estimate is for the lake below the County 12 bridge. No dead catfish were found upstream of the CR 12 bridge to the confluence of the South and Middle forks of the Zumbro. This is an absolute minimum estimate only. There were definitely floaters mid-lake that were unaccounted for in the counts. Also a lot of vultures eating some and we sampled a fair amount of developed shoreline where folks may have picked up and disposed of some, not to mention fish that may not have surfaced. Bottom line is we estimate the kill at 500 to 1000 channel catfish.

– All of the fish that were observed on Monday were determined to be too decomposed for pathology lab for testing. Staff also noted that no other species were affected by the kill, so the indication is that it was a disease or other factor that was specific to channel catfish. Seeing only one species generally indicates that the kill was not caused by a pollution or chemical spill.

– On Tuesday, July 27 our crew returned to the lake to try to collect either fresh dead or live fish that could be sent to the pathology lab. They were only able to collect one channel catfish and did not observe any new dead fish. We will be transporting this fish to the lab later today or tomorrow. Fisheries staff are also returning to the lake today (Wednesday) to see if we can collect additional samples. Pathologists may be able to give us some likely causes based on the observations we have so far, but conclusive results might take a few days. With only one fish for analysis, it is likely we may not be able to nail it down.

– Based on our observations over the last two days, it appears that whatever caused the kill has run its course and we are not finding any new dead fish. This is typical for a disease outbreak.

Please give me a call or email if you have any questions or further observations.

Kevin Stauffer
Area Fisheries Supervisor
Minnesota Department of Natural Resources
1801 S. Oak Street
Lake City, MN 55041
651-345-3365 x229
[email protected]

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That or Tyler Holm was kissin them before release. Kiss of death ya know?

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If I kissed every single fish I’ve caught this year out of the Zum, it wouldn’t amount to even 25. Taint me.

I hope there is a logical answer thou. I’m hoping ma nature is clearing a path for a trophy fishery.

Another update from R.O.

Thanks Tyler for posting the information I sent to you. It is really helpful to get this information out to anglers and concerned citizens.

I just wanted to add another update. We had a crew on the lake again yesterday and were able to collect four more channel cats and they are on their way to the pathology lab this morning. I can also report that we are not seeing any newly dead or stressed fish. If any one has a different observation, please let me know as soon as you can. Also, if you see or catch a channel cat that is obviously stressed or has a visible anomaly (fungus growth, sore, tumor, etc.) – please refrigerate or put it on ice until we can come pick it up. Please do not freeze the fish, as this substantially reduces the value of the specimen for lab analysis.

I don’t expect any lab results until next week, at the earliest. Some things can be identified rather quickly in the lab, but others can take awhile if they need to grow cultures, etc. It is also common to have a situation where the obvious things (like the fungus observed on the fish) are a secondary infection that took hold because of something else (like post spawning stress, water temp changes, parasites, etc.).

I have responded to a large number of phone calls, media requests and emails over the last few days and tried hard to keep the public informed on the situation and what we are doing to investigate. I’m sure I missed a few people in the process, but as always, I encourage all of you to contact us directly with questions and concerns.

Kevin Stauffer
Area Fisheries Supervisor
Minnesota Department of Natural Resources
1801 S. Oak Street
Lake City, MN 55041
651-345-3365 x229
[email protected]

Kevin is a great communicator!

…and a heck of a guy. If you ever have a chance to go to one of his seminars, do it!

Thanks for keeping this post updated guys!

Channel 11 reported today that it was a fungus specific to channel cats.

AKA: Tyler Ich

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AKA: Tyler Ich

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I wonder if he’s any relation to Marty Stauffer, the famous naturalist/nature documentarian?

Here is another update from R.O.

Good morning Tyler,

I would like to pass on additional information that we have on the fish kill that occurred in Lake Zumbro in late July 2010. I’m trying to get this to as many people as I can, so I would appreciate it if you would forward to other anglers you know and/or post on web forums. Please give me a call or email if you have any questions or would like additional info.

According to DNR pathologist Ling Shen, the test results for channel catfish show that the fish kill was likely caused by multiple infections. However, the primary cause of mortality appears to have been a bacterial disease called Columnaris. The bacterium exists naturally in fish populations and expresses itself when stressful conditions exist. The infection is brought on most commonly when water temperatures increase rapidly. The increase in water temperature often brings an increase in spawning activity, which coupled with stress caused by temperature changes, make the fish more susceptible to the infection.

Channel catfish examined by the DNR pathology lab also found other bacterial infections (Aeromonas and Pseudomonas) and a gill parasite (henneguya). These infections may have contributed to mortality in some fish, but were not the primary cause of the fish kill. Results of viral testing are still pending, but it is unlikely that viral infections caused mortality of channel catfish.

DNR Fisheries staff returned to Lake Zumbro on Monday, August 2 and did not find any new mortalities of channel catfish. Fish kills from Columnaris outbreaks are relatively common across Minnesota and these outbreaks do not have any long term effects on fish populations. In most cases, the numbers lost are small in relation to the total population, and we expect minimal change in angler success that can be attributed to Columnaris disease. At this point we have concluded our investigation of the Lake Zumbro fish kill, but will follow up on any new reports of dead fish that may happen. If lake residents or anglers observe any further fish mortality, please give the Lake City Fisheries office a call as soon as possible.

Sincerely,

Kevin Stauffer
Area Fisheries Supervisor
Minnesota Department of Natural Resources
1801 S. Oak Street
Lake City, MN 55041
651-345-3365 x229
[email protected]

On a side note, I’ll be heading to lake Zumbro tonight to do some drifting for channel cats. I will report back late tonight, or tomorrow, hopefully with some good results.

Here’s some interesting information on the Henneguya infestation in channel catfish:

http://www.jwildlifedis.org/cgi/reprint/21/2/177.pdf

Apparently what happens is these little critters burrow into the gill tissue which responds by encapsulating them in scar tissue which is later converted (I think… scholarspeak is a bit hard to follow sometimes) to connective tissue. If there are enough of them, the encapsulation process can actually cover the business end of the gill itself and suffocate the fish.

Essentially it’s ichthyological emphysema. Ugh.

Columnaris seems pretty common. It gets in aquarium fish. It might even be what kills your bullheads in your bait tank.