Pond Boss Forums INTRO Questions & Observations Whats killing my browns but not the bows or brooks

Hey Guys- Last fall I stalked my 1/4 acre pond in Ontario, Canada with 50 Rainbows, 100 Brook trout and 25 Browns. All where doing great untill thursday I started seeing something I haven't seen before...I started seeing the browns crusing the shore lines but never thought anything about it. Yesterday morning I went down to the pond and found 4 floaters (all browns) and by the end of the day had found 2 more dead and pulled out one gasping for air on the surface.

There where some changes made to the pond in the last few days but I can't see it doing anything to just the browns.

On Tuesday I pulled out my 3 air stones that where on the bottom (running 12 hours per day) and swapped them out for membrain diffusers and have them set floating 4 feet from the surface.

I was also starting to get quite a bit of algea on the sides of the pond (had a great bloom 3 weeks ago) but now matts are building up on the sides. I decieded to dye the pond as I am just feeding anyway. And it should help to keep the pond temps down a little. I have been removing the algea on the sides manually.

As far as the pond temps go, currently its 61 on the surface and 59 on the bottom (16 feet of water)

With the temps that close is it possible the pond had done a spring turn over? as there is no clear sinces of temp change indicating a thermocline?

What I don't get is that everyone told me the Browns are the hardiest trout you can put in the pond as far as water temps go and they are dying and my brook trout are doing amazing. I even had 4x6' cage 4' deep with 6 brooks and one brown and the brown died yesterday and the specks are better than ever.

Any idea's???
Thanks Ryan

Here are 2 pics of them crusing the shore the other day.

Sorry to hear about this Ryan, hang on for some expert feedback. Hopefully a few of our resident trout experts will chime in.

I can't imaging that changing the type of diffusers had anything to do with the deaths but perhaps the change in the location of the diffusers and dyeing the pond. To summarize:

You changed:

1. type of diffusers

2. location of diffusers

3. dyed the pond

When did you dye the pond relative to the change in diffusers? (in other words did you dye the pond a week before the diffusers, or the same day?)

Experts?

(I see Bruce Condello just posted, hopefully he can weigh in on this).

PAGING DR. CONDELLO, PAGING DR CONDELLO, DR CONDELLO PLEASE PICK UP THE WHITE COURTESY PHONE LOCATED IN THE MAIN LOBBY....

Hmmm... so brook trout are doing fine but browns are not? Are you sure the brown trout swimming around in shallow water in distress makes you more aware of them vs. the brooks that could be sinking to the bottom? But then again you did mention the cage situation...

How old, how large, and what sex are each species? Is it possible the browns that are dying are egg bound females or just older fish? It's not usual for trout to only have a lifespan of 3 to 4 years in ponds.

If this truly is only effecting browns then it shouldn't be a water quality issue as if anything brooks are fussier than browns. It may be a pathogen that the brooks have been exposed to previously but the browns have not.

What kind of pathogens are your fish tested for at the hatchery? Are your brook trout IPN free? It's hard to find a source of brook trout that are, but they develop an immunity. Perhaps your brown trout have never been exposed to it until you put them together?

Water temp is not your problem. Browns although a bit more hardy get their hardiness sometimes exaggerated in literature. They still need cool water temps and lots of oxygen.

If you find another one gasping at the surface can you take a look at the gills with a magnifiying glass and see if there are any parasites on the them?

Less than 30 minutes to your first expert feedback, dang ya gotta love this place.

Luckily I just checked out of the Holiday Inn Express a few minutes ago and had access to an Internet Cafe.

Sometimes that's all ya need.

Besides, you're not fooling anyone, I'd venture to say that you've raised more fish than...

...dang, now I have to search Google for an appropriate analogy.

Just got back from taking a walk back out to the pond again. Only had one more this morning that was floating...another brown.

Here is a pic of the dead one I just pulled out.



I honestly wondering if it wasn't possibly something in the dye that has done it. The browns where from a different hatchery than the Brooks and Bows. I added the dye on Tuesday and changed the airators on Wed.

I am 100% possitive that all the brooks and rainbows are fine. I feed them close to the dock and I can scoop them up...did it last night and got 2 bows and about 6 brooks and they all looked perfect and the #'s of what was feeding looked normal from even a month ago. So I am sure they are all still living.

If I see one gasping for air again I will check out the gills...also have to find a magnifying glass!

Ryan

Oh, the 25 or so browns I stocked where all in the 10" range in the fall and are now in the 12-14" range and where doing super healty up untill now...I actually even cought 2 about last friday and everything looked fine then. The Brookies are about the same size with some being 10-12" long. All where stocked last fall in September

Ryan

Ryan,

I can't imagine there is anything in the dye itself that would harm them. Perhaps the browns were in the wrong place at the wrong time, and when you moved the diffusers you stirred up hydrogen sulfide or something? From my experience having brooks and browns in my pond, the browns hung out in deeper water near the bottom while the brooks cruised the breakline of the pond.

The fact that only the browns are effected makes me think it's a pathogen thing that the browns have not been exposed to (you said they came from a different hatchery) but the brooks have developed an immunity to. The brooks may have been carriers. Like I said a lot of brook trout will test IPN positive and can even be sold in some areas, but never show any symptoms or problems. I'm not saying it's IPN as it could be another pathogen.

Again what pathogens are the two species tested for from both hatcheries? There should be some required testing.

Don't be surprised if this ends abruptly with no clues.

Cecil- I am not sure on the pathogens and havn't talked to the hatcheries. The Hatchery where I got the browns is quite large and supplies all over Ontario and is one of the fiew suppliers of Browns in the area. The other hatchery where I got the brookies from is quite small and more of a Mom & Pop type little place with him specializing in only brookies.

One thing I have been noticing today and even yesterday that I never gave much thought to is that all the browns are in one area of the pond where there is a small feeder creek running into the pond (I live in a 15 acre woodlot and at the top of the property there is an old beaver pond that currently just holds water, and TONS of frogs)...it then outfeeds out of there and meanders about 200 yards thru the tree's (previous owner lined the creek with gravel)and then drops about 3 feeet just at the edge of the pond. There is an outfeed in the pond but it just drains into the swampy area of our property.

I am wondering if they are not gathering in that area for oxygen comming down from the creek water.

Unfortunatly I do not have a DO meter in order to test the water.

Also, on a side note...I decieded to toss in a line in the area where I am seeing them and within seconds I had a very livly brown that looked more than healthy with very bright red gills. I also got a brookie on the next cast and it too was also very healthy (that one I kept and will be going on the smoker tomorrow). While I was fishing in that area I did see one other brown that was closer to the surface and it was noticably a different colour than the livley one I cought.

I also gutted a few of the fresher dead ones just to see if they had eggs...and non of them did.

I am baffled as to what is going on....hopefully they pull thru this.

Ryan I wish I could add some kind of explanation but I'm stumped.
Cecil's diagnosis seems to make the best sense since it's only affecting the browns, maybe the warmer temps has increased the effect of the pathogens and that's why it waited this long.
I hope it ends soon and doesn't affect your other trout.

You mentioned moving your aerators to shallow water, do you run them only at night to help cool the water while increasing oxygen?

You mention a feeder creek where the browns have been staying, is there any chance of chemicals coming from someone else's property.

I have thought of that in the past (chemicals comming down from the other pond) and honestly I am not sure. The beaver pond is still in a wooded area is close to farm fields (my wifes uncle cash crops the fields there and it was well over a month since we fertilized or was even around the fields).

Like I said...I am stumped and I hope like Cecil said...that it will probably go as fast as it came...I am keeping my fingers crossed for that!

Ryan

Another possibility for congregating at the inflow is that is what fish that are stressed do. Many times disease problems reduce their ability to uptake oxygen so they look for areas of increased oxygen.

My guess is this will run it's course and most of your fish will survive, but it may reoccur at the same time of year next year or it may not.

I would be interested in your D.O. readings, but if it wasn't for your brookies being just fine, my WAG would have been your dye has cut off light from macrophytes and algae. This could have caused them to die and D.O. readings to plummet. But seeing that the brookies don't seem to be effected that does not seem to be the case.

Just an observation about the dye used in the pond.....You said you thought it would keep temps down, but I believe it did just the opposite and raised the water temperature. Darker colors absorb sunlight and heat, lighter colors will reflect more heat. Also placing your new diffusers only 4 feet from the surface will leave most water under them un-mixed and oxygen will be quickly depleted and even possibly stratify the pond.

Just some quick thoughts.....

Non dead today :-) So what is the idea placement for diffusers for trout in a pond when the average depth is 10-16 feet. Last year in the hottest of the summer the bottom stayed below 66 degree's. I did loose almost all of my rainbow last august(reason I re-stocked) due to the pond turning over after 6" of rain in 1.5 hours and the little meandering stream that usually has no flow after the end of may turned into a raging river and turned the pond over and brought up more crap from the bottom than I ever saw (leaves, twigs, skum and very smelly water) there where aprox 20 rainbows that survied.

Ryan

I'm going to try and over-summer trout in my pond (yeah, I know, it's an iffy proposition in Indiana) by aerating from the bottom in the deepest portion of the pond. I'll run the aerator anytime the air temps are below 70�F, which should be most every night and portions of the mornings.

I haven't searched yet, but I'd really like to find a thermostat that would automatically turn on the aerator at 70� and off at 71� and higher.

If anyone knows how to do it, I'm all ears!

I'm not an aeration officianado, but if you do not aerate from the deepest point in the pond, that water will become anoxic and totally devoid of oxygen.

I would place the diffusers in the deepest part and run them nightly as trout require very high dissolved oxygen levels and that will allow them to survive temporarily higher temps...lower temps with lower oxygen will result in a quicker kill.

Perhaps one or more aeration experts can weigh in on this thread and offer real world experience here.

Here ya go Scott... Adjustable Digitally Temerature Controlled Outlet

Okay, this is going pretty well against everything anyone up here has told me (only have the diffusers at mid depth) in order to keep the cooler water down on the bottom....heck, alot of trout guys up here don't even recomend diffusers at all but rather just fountains running at night which the say prevents the turning of the water.

I think next year I am going to change my plans for the pond and just stalk 12" brookies this fall for eating over the winter and spring and then start stalking walley and bluegills


Ryan

Ryan, that is true as to fountains. As aerators, fountains do a pretty poor job, but look nice.

If you have cold spring water that flows over rocks and into your pond to aerate it well, I would go with the mid-level placement or fountains as well. If this is not the case in your pond, during the summer months, the cold water beneath your thermocline is a dead zone until the Fall "turnover".

Placing the diffusers at the bottom will allow upper waters rich in dissolved oxygen to be drawn to the bottom while lifting the lower, oxygen deprived waters to realease the toxic gasses dissolved in them and to take on oxygen.

This will raise the temps in the bottom layers, but diffusing during the night only will lessen the rise in bottom temp.

Nice little gizmo Rainman.

Esshup:
I guess it depends on where it is installed. This unit is designed for indoor use. The IP20 rating ONLY makes it "Child Finger Safe". One would need at least an IP65 rating to use outside.

I doubt you would have an issue with starting current, at least for a while. Most window air conditioners, electric heaters, furnaces have a "Soft Start" which gradually ramp up current. While not knowing what your pump is, if it starts, like right now, it would reduce the life of the unit.

While this is an experiment, and if you decide to use it in the required environment. I would mind my P's and Q's, whatever that means.

BTW: I always did feel better after 120 volts surged through my body. Amp's are the ones that make it stick.

I have a couple of ideas, but I would like to see if the aeration experts have something to say.

My guess is Scott's pump is indoors and a housing is easy to build anyway.....lol

OK, But I thought he wanted to monitor "True Outside Temps". And tight at that!

Cant do that in a housing!

I sent this link as a PM but thought there may be many readers of this thread that do not understand the physics and applications of aeration. Heck, we all need a refresher course now and then anyway!

The aquarium industry created MANY myths and falsehoods about bubbles and far too many take it as fact....This old thread helps dispell some of the myths and explains a lot of the physics.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=33038#Post33038

Guys I have used that thermostat for 2 years to turn my aerator on when it's cool and off when the temp. rises, it works great, as you can see it's mounted under a small cover, no need to put it in a box.

http://www.pondboss.com/forums/ubbthread...true#Post129188