Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations What do I do wih this pond?

Well, some would call it a lake, I call it an irrigation reservoir.

https://imgur.com/7onLDFK

It is about 7350 feet in elevation on the western slope of Colorado. It is about 12 acres when full. Probably 14 feet deep. 10 acres of it has a pretty flat bottom between 12 and 14 feet deep. The edges are steep. Drops to 5 feet deep, about 10 acres, in the fall, but starts refilling within a month. It gets drawn down every summer and refilled all winter. The biggest problem is the silt load in the water. It is cool/deep enough for trout, but they just don't seem to live very long (4 years) and they are getting expensive. I stocked with bluegill and CC. The CC did ok, but no evidence of spawn, the bluegill disappeared.

Very regulated in what I can stock. Pretty much trout, LMB, BG, CC, YP, BCP, FHM. There are already a ton of FHM and crayfish. Maybe 50 to 80 CC, running about 6 pounds. Originally stocked 90 CC, about 7 inches long, have only taken 6. Not sure on the survival rate.

I'd love a self sustaining fish population in this lake. I'm ok with being a predator. Ideas are welcome.

Brad,

That bluegill didn't reproduce is a sign that you have a coldwater lake. For trout to reproduce would require running water. They live a long time so could grow large potentially.

Walleye and yellow perch might reproduce there. Walleye will need some riprap for spawning.

Who's regulating the species which can be stocked? YP, SMB and WE might be better geared toward reproducing and thriving in cooler temperatures - at least they spawn at lower temps than bg and lmb. Is there any vegetation?

Do you have an idea of what the temperatures are like in the 5' to surface range between may and july? I bet that's the info which will be required to pull off a self sustaining fish population

Hi Brad. No expert here, but I'll share some experiences from my time down here in Dolores area.
Trout: you may be doing well to have them live 4 years. My supplier indicates 2 or 3 years is what to expect for the hatchery RNBT he provides. They grow to 25" or so in that time.
BG: our regional fisheries biologist, based in Durango, describes very limited BG recruitment in all our cool water ponds and lakes. In contrast, GSF do very well. In my pond, I've yet to see YOY BG; GSF are thriving. These two species have been in my pond for 4 and 3 years, respectively.
YP: I'd agree that YP may do well for you. Walleye are gaining a foothold in McPhee reservoir. They were bucket stocked illegally. Their numbers stayed low for several years; the individual fish got bigger and bigger. Now there is evidence of possible recruitment.
BCP: These guys are abundant in some eastern Colorado waters. I know of no western slope waters that have acceptable sized crappie. There are plenty of stunted ones.
SMB: I know, I know, our fisheries people dislike them. Their concern is smallmouth predation of our several threatened native fishes in the Colorado drainage.
In conclusion, I'd have to say GSF are tops on my list for our cool water ponds. They are persisting around here despite LMB predation. I help them out by removing every bass I catch out of my pond.
And, while struggling, YP also continue to reproduce and recruit in lower numbers.
How about cover in the lake? Our western reservoirs, where water levels fluctuate so dramatically, are not filled with desirable plants, are they? Common carp get many of them, but drying and freezing in the winter when the water is down 10 to 100 feet doesn't help.

4Corners,

I didn't know that the trout could grow to that size so quickly and were that short lived.

Walleye and SMB are prohibited by Colorado Parks and Wildlife on the western slope of Colorado because of the endangered fish in the lower Colorado River. I asked about Pumpkinseeds and got denied on that too.

I have not done any temperature samples yet. Everyone is right, it is a cool water lake. Not really cold, but cool.

The lake has a lot of cover around the edges when it is full. Almost nothing when it is low. I know I need to fix that no matter what.

I'm interested in yellow perch. Question, would it be possible to manage them without many predators in the lake? I'm not afraid to eat 5 inch perch.

Brad, YP management without predation is possible. It is probably also very difficult. Bill Cody is your man for this info. He might suggest supplying spawning substrate such as branches placed in shallow water that could be used to remove some of the egg ribbons in spring. This might be one step towards lowering YP recruitment.

I have no idea if the following has been tried or if it could work. But here goes: combine the YP with panfish as predators, such as GSF and/or BCP. Either the sunfish and/or the crappies could eat many of the smaller perch, as they both have reasonably large gapes. Then you would be responsible for thinning out the perch that got too big for the predator(s). Those perch would certainly be approaching 5 inches or more. There would be no predators large enough to eat big perch, the size you'd prefer.

You could have several trout as bonus fish. Tiger trout or rainbows come to mind.

Just keep the LMB and northern pike out of the pond.

Any experts care to evaluate the potential of a YP fishery with GSF and/or BCP?