UPDATE: UL White Bass Dieoff

[TubeDude]

White bass continue to die off and feed the gulls and pelicans on Utah Lake...and probably the walleyes and catfish too.  One recent report I got included the information that some of the deceased whities were covered in a brownish fuzz.  Sounds like the fungus that Provo River Browns get after the stress of spawning in warm fall waters.  I emailed Chris Crockett of DWR with an inquiry as to what they might have found up to this point.  As always, he was quick to respond and here is his reply:



     Pat, I don't have any clear answers yet.  We have been out on the lake three times in the last week.  Basic water quality metrics look normal, our partner agencies have tested for cyanobacteria (nothing to speak of there), and our fish health pathologist has examined several white bass.  We were able to collect several recently deceased and/or dying white bass and thus far everything has looked normal.  I think the "fuzz" anglers are reporting essentially comes after they have been dead/dying for any length of time and it's not the cause of their death (they are already stressed, beat up, dying, and then they get some fungus/bacteria growth).  We have not seen any signs of a spill, contaminants, or pathogen.  My best guesstimate right now is that it's due to accumulated stressors (quick temp increase, a few wind/turbidity events, thin/underfed fish, etc,) but right now that is only a guess and not a very satisfying answer.  

 

Any thoughts or hypotheses?  




[font="Tahoma", sans-serif]Chris Crockett[/font]
[font="Tahoma", sans-serif]Central Region Aquatics Manager[/font]
[font="Tahoma", sans-serif]Utah Division of Wildlife Resources[/font]

[MSM1970]

Thanks Pat, hopefully they can give us an answer good or bad before too long, WB is the only fish I have seen belly up. If the predators are not dying, they should be pretty hungry later this year as the WB thin out. I can only give account for Lincoln, but I do know the walleye spawn was very poor this year,

[Mooseman75]

Mike I'm guessing you have launched out of Lincoln. I went to launch there yesterday but when I got there I realized I didn't have a drain plug. I had them in the door of my truck which is in SLC in diesel repair shop, I was using my dad's....so long story short I didn't get out. So I was wondering what is the depth of the channel and are there continuing die off of WB or has it stopped? Don't know if you've been out. I didn't see any belly up like the week before when I was with piscophilic.

[MWScott72]

Are we talking 10s, 100s, or 1,000s of whites dying and is just around Lincoln or general lake-wide? It would be a day (for me) if the whites took a big hit and didn't show up in numbers for the spawn.

[MSM1970]

Mike I'm guessing you have launched out of Lincoln. I went to launch there yesterday but when I got there I realized I didn't have a drain plug. I had them in the door of my truck which is in SLC in diesel repair shop, I was using my dad's....so long story short I didn't get out. So I was wondering what is the depth of the channel and are there continuing die off of WB or has it stopped? Don't know if you've been out. I didn't see any belly up like the week before when I was with piscophilic.

Saturday morning I counted 13 in the harbor,
Ya I have been there a few times this year    . reading 2 ft+ going out the chanel,  but just like always keep the motor away from the center of the dock, there is a rock pile, 

You better sick those plugs in the boat and get a couple extra,

[Piscophilic]

Are we talking 10s, 100s, or 1,000s of whites dying and is just around Lincoln or general lake-wide?  It would be a day (for me) if the whites took a big hit and didn't show up in numbers for the spawn.

MWS, almost 2 weeks ago I saw around 100 floaters in the stretch between the airport and Powel Slough. Others reported them at Lincoln beach, so I would say it is lakewide and total numbers would exceed 1,000's because it is such a big lake.

---

Hey Pat,

Thanks for the follow up! I had just sent Chris a request for an update this morning. Then I got on here and saw you had gotten one. One step ahead of me as usual. 
I was planning to go out there this weekend, but I may wait a bit longer. It sounds like the critters may still be very well fed. I am curious to see if most of the floaters look old though.

[TubeDude]

Hey Pat,

Thanks for the follow up! I had just sent Chris a request for an update this morning. Then I got on here and saw you had gotten one. One step ahead of me as usual. 
I was planning to go out there this weekend, but I may wait a bit longer. It sounds like the critters may still be very well fed. I am curious to see if most of the floaters look old though.

Still waiting for a reply from Chris about whether or not the fish had been checked for parasites or a pathogen (bacteria or virus).  Also asked for his input on whether it was a lake-wide problem. 

I have been holding off making my first major whack on the lake pending settling weather conditions and a more optimistic outlook for the fishing.  So far not much cat action either...and the walleye fishing has been the worst in years.  I'll probably start coming down after the middle of the month...both to check on white bass numbers at a couple of usual spots and to try for some post spawn walleyes...and of course some kitties.

[Piscophilic]

It will be interesting to see what Chris says about lake wide. I figured it had to be, considering what I saw and heard, but the wind does move the floaters around. I'm getting a bit worried though. Mike said he hasn't caught an incidental WB in his eye hunting trips since before the floaters showed up. If there was a really large die off, would most of the fish float or would most of them just sit on the bottom? The day I saw all the dead ones on the top, MM75 actually snagged a dead one on a circle hook that was dragging right on the bottom.

Time will tell I guess.

[TubeDude]

It will be interesting to see what Chris says about lake wide. I figured it had to be, considering what I saw and heard, but the wind does move the floaters around. I'm getting a bit worried though. Mike said he hasn't caught an incidental WB in his eye hunting trips since before the floaters showed up. If there was a really large die off, would most of the fish float or would most of them just sit on the bottom? The day I saw all the dead ones on the top, MM75 actually snagged a dead one on a circle hook that was dragging right on the bottom.

Time will tell I guess.

As a general rule, most dead critters...animal, bird or fish...will float after dying.  Decomp produces internal gasses that float the deceased.  But not always.  And the colder the water the slower the decomp process and in some cases it is never enough to float the body. 

In the case of the white bass, they also have air bladders so it would not take much to float them to the top.  I doubt the bottom is littered with white bass carcasses.  More likely that most of them float up and become pelican chow. 

I am beginning to believe it might be a lakewide disaster.  Anybody notice any Russian Tanks along the banks of the lake recently?  But if history tells us anything not all the fish will die and there will be enough left to spawn and restock the lake.  Whities are prolific.  Just gonna be some poorer fishing for all species until they restart things.

[joatmon]

I saw several dozen white bass floating and/or stuck in the detritus along the banks near Lincoln Beach last Saturday.  I didn't observe any in the act of dying.  The birds seemed to be eating well.  

I got absolutely zero bites in a couple of hours of fishing.  I even dropped my flasher transducer over the edge of the dock, but at 2 feet of water did not observe or expect to observe any swimmers.  I talked to several other bank fishers and boat fishers and seems they had similar luck to mine.

I may have to find a different water body to get started in the contest until the die-off/gorging runs its course, or fish somewhere else for something else.  Already put my ice gear away.  I did get the canoe out, so I might try Yuba to see if the wipers and walleyes (or heck, even some carp) are willing to play.  Or ice off somewhere?  Options, options...

[doggonefishin]

This may or may not have any significance, but on my last ice fishing trip to UL, in early February, I noticed some odd behavior in the white bass and the body condition had deteriorated notably from fish I had caught earlier in the ice season.  The fish fillets were markedly less substantial than usual.  Normally, white bass tend to orient close to the bottom third of the water column when ice fishing at UL.  On the last trip, they came through closer to the surface and sluggishly moved a little up or down when jigged.  (They came through in the zone crappie usually appear, but I caught enough of each that it was apparent that a lot of these marks were WB.)  Finally, WB usually are fairly scrappy when hooked.  These fish were notably not.  The crappie, perch, and bluegills seemed to be normal.  

I haven't corresponded with Chris for a couple years, but still have his email.  I will forward this to him tonight and report back what he says.

[TubeDude]

I got a bit more input from Chris...regarding my question on potential parasites or pathogens.  Here 'tis.


[font="Calibri", sans-serif]Pat, our fish pathologist team in Logan (Fisheries Experiment Station) has examined several white bass.  They did note the parasite load was relatively high, but not very dissimilar from inspections in previous years (we often disease certify white bass in Utah Lake to use in our wiper production program).  They are not aware of any pathogen specific to white bass and the cultures they have run for the "usual suspects" have not revealed any issues. [/font]


Thanks again Chris

[Piscophilic]

Thanks for another update Pat. I'm curious, are the Loys still netting carp? If so, I would expect they might have some observations that would be useful.

[TubeDude]

Thanks for another update Pat. I'm curious, are the Loys still netting carp? If so, I would expect they might have some observations that would be useful.

I'm pretty sure their carp seining contract expired. 

Chris mentioned in his reply that he had received info from others on how poor of condition the white bass seemed to be.   I suggested that a big part of the problem might be in the food chain.  There is no large population of small species (minnows) for the white bass to feed on year round.  They glut heavily on their own young for a few months after the spring spawn, but by fall the young are too large for adult white bass to eat.  A good thing or there would be no young left each year.  I know that Utah Lake white bass and other small species will resort to slurping up midge larvae to supplant their diet when there are no young of the year to dine on.  But as in past drought years, the mud flats that produce large quantities of midge larvae are now dry or too shallow to support midge life.  So that would mean a big missing part of their potential survival diet. 

I also mentioned to Chris that a similar situation occurred at the end of a long drought period in 2004.  The white bass spawn that year was poor and the food resources were low.  Consequently the white bass population plummeted...and that messed up the predators.  In the fall of 2004 the fishing for large walleyes was great, since they were not full of other food and were more susceptible to the silly stuff thrown by anglers.  But the fish were noticeably thinner.  A lot of larger walleyes "went to bed hungry"...as the ice covered the lake.  And many of them died under the ice.  Walleye warriors fishing for them the next spring would frequently snag large dead walleye corpses that had died under the ice...and few living walleyes were caught during the "spawn".  And the few post spawn walleyes that had survived were mostly skinny.  I am attaching a picture of one that ate a minnow I was dragging for catfish in the early spring of 2005.

[big_griggs]

That looks like a eel its so skinny

[MWScott72]

Wow, Pat...that is one skinny eye!

I last fished UL probably mid-Dec to early January when the harbors had frozen up. We did well on whites a few times, and contrary to what is being said here, they looked to be in good condition at that time. Average size seemed to be larger too, so I was looking forward to some bigger fish late spring during their run. It will be interesting to see what the bios come up with. Thanks for posting the updates from Chris!

[TubeDude]

Wow, Pat...that is one skinny eye!

I last fished UL probably mid-Dec to early January when the harbors had frozen up.  We did well on whites a few times, and contrary to what is being said here, they looked to be in good condition at that time.  Average size seemed to be larger too, so I was looking forward to some bigger fish late spring during their run.  It will be interesting to see what the bios come up with.  Thanks for posting the updates from Chris!

I remain cautiously optimistic that the problem is not lakewide and that there are still areas unaffected...and that the fish still maintain a healthy population in at least some spots.   Water levels are low and runoff appears to be low at this time.  Hopefully the lake will rise and the flows will improve by spawning time in May so that any surviving white bass of spawning size will do the deed and help repopulate whatever is lost in the affected areas.  They are prolific little buggers  and they can produce a whole lotta babies if spawning conditions are favorable. 

Utah Lake is a big lake...with many different areas of different bottom composition, depth and food resources.  It is possible to have multiple separate populations around the lake that can be independent of the rest.  And contrary to what some might think, some of these populations tend to remain in the same general areas if they find the food, temperatures and other conditions to their liking.  So it is reasonable to hope that the problems observed in one area are not a factor in others.  I hope, I hope, I hope.  It is going to be another week or two before I start fitting Utah Lake into my fishing schedule.

[Therapist]

Been following this thread. I am wondering if these fish got into a hypoxic situation just as the ice was melting and were blown up on shore after the ice out. With the lake as low as it is, there had to be areas that just did not have enough oxygen, especially towards the end of the ice cap !! The fact that they have been unable to identify any disease or parasite lends even more credence such an episode. Just my 2cents worth !!

[Piscophilic]

Been following this thread.  I am wondering if these fish got into a hypoxic situation just as the ice was melting and were blown up on shore after the ice out.  With the lake as low as it is,  there had to be areas that just did not have enough oxygen, especially towards the end of the ice cap !!  The fact that they have been unable to identify any disease or parasite lends even more credence such an episode.  Just my 2cents worth !!

Good thoughts, I wondered that as well, but theones I observed "dying" were almost a month after ice off. May have been weakened and just not able to recover though.