Lees Ferry is in trouble

[WMF]

Originally Posted by stoneflynut

Please read my post above (#5 this thread) regarding documentation. I spoke with Scott Rogers last night and he emphasized Game and Fish is just floating this idea of reducing the number of small trout and have not formally proposed any action. They want anglers to know there is a train wreck coming down the tracks if something is not done about it soon. As to the idea of letting larger rainbows eat smaller ones: That approach has not worked at Lees Ferry in the past and rainbows are not generally considered effective predators on small fish in freshwater systems like the Ferry. If they were, we'd all be throwing streamers. Lastly, comparing one tail-water fishery with another puts you on thin ice. Each tail-water is distinctly different. For example: high flows on the Juan (which also has a thriving brown trout population) run in the 5,000 cfs range while running 25k or even up to 40k at the Ferry is not uncommon. Some other differences that occur: water temps, nutrient loads, elevation, insect diversity, latitude, sediments and spawning substrate availability, and other species present, to name a few.

Joe, I appreciate the "conservation guru" comment but don't feel comfortable with it. I'm just a biologist/writer with enough experience to make himself dangerous when piping up on issues so, please, take my comments with a grain of salt.

So you're saying that the removal of trout has nothing to do with the chub, and everything to do with making the trout bigger? As a side note please contact the grand canyon trust and let them know as a biologist your opinion is that "rainbows are not generally considered effective predators on small fish in freshwater systems like the Ferry". Cause they have a suit against the U.S. B of R for stoping the trout killing in the colorado... because they eat chub minnows... Wait I might have stepped off the thin ice...

[Driftwood]

Originally Posted by bhickfish

I just hadn't heard about it is all. I had only heard about mechanical removal below the paria.

I told you guys this stuff happens when there is too many mouths to feed. The rumors ..rememeber. Different spot but same problem.

[stoneflynut]

Originally Posted by WMF

So you're saying that the removal of trout has nothing to do with the chub, and everything to do with making the trout bigger?

I'm not aware that humpback chubs have been sampled at Lees Ferry since the dam began operation; water's too cold. I am saying that Game and Fish is talking about the need to remove small rainbows from Lees Ferry because they are far too abundant to be sustained when equalization flows stop and reduce the amount of available habitat. Clear enough?

It is a mistake to lump together what Game and Fish is warning us about and what Grand Canyon Trust is doing.

[stoneflynut]

Originally Posted by WMF

I didn't lump game and fish in with GCT. So wouldn't the trout just push down the river?

Didn't mean to imply you did. That comment is meant to warn folks that what Game and Fish is talking about is totally separate from the chub issue. There seems to be a tendency to think the idea of thinning out small rainbows from the Ferry stock must have something to do with chubs when it actually has everything to do with maintaining a quality trout fishery.

As for the trout just pushing down the river, I'm not aware of any studies or reports that indicate the Lees Ferry trout are migratory or that they disperse downstream. I am aware that as you move downstream the river becomes less productive and food resources are less available. It wouldn't seem desirable for a fish to move downstream where there is even less food.

[Flats Man]

Anyone who has fished the Ferry over the past decade has seen the "boom and bust" periods that have occurred. There were times about 6 or 7 years ago when three-fish-day was a good day. It appears that now we are approaching the other end of the spectrum where we have had three really good years of a spawn, placing tons of fry in the river along with two relatively young age classes of fish. Every fish gotta eat and there is only so many midges and worms to go around... THIS IS A HUGE REASON THOSE FISH DO NOT GROW MUCH PAST 18-19 INCHES.

This same problem occurs up at Lake Powell every few years where the Striped Bass forage to the point that the shad become almost non-existant. The striper popluation eventually re-sets, as does the shad, and for a few years following the fishery is good again once the predator/prey ratio is in balance.

Back to the Ferry. There is no right or wrong answer here, just a bunch of strong opinions; understandably so. This is a premiere fishery that we all love and want to see thrive. Hopefully the decision that gets made here is ultimately in the best interest of the fishery and the anglers that spend a ton of money each year supporting the local businesses, guide services, State Park, and Fish and Game.

[Bighand]

Leave them alone. Every ones wants wild trout. There they are growing before your eyes.
If they wash down river more food for the Colorado Pike Minnow. Little known fact about this fish is once it reaches 12 inches it eats almost entirely smaller fish. Don't see them cutting their belly open to see how many of their own they have eaten.
Plus they have 10 per cent chance of surviving so their numbers will drop naturally.
I don't have any idea what the river flows are going to be the coming years. There may not be another spawing of wild trout for many years.
I am not sure about this. But, I am pretty sure there is no one running up the river with stocker trout stocking the river every month.
If Game and Fish wants to do something why not bring back the scub population.
Isn't Lee's Ferry one of the Blue Ribbon fishing spots for Arizona?

[LV NRG]

Stayed up river for 6 days and as always it was beautiful.

The sad part of fishing at Lees Ferry is there are snake fish.
Big heads and small bodies, Also a great number of small fish.

I do know I saw this about 5 to 7 years ago.

Starving fish....

Please do not be mad at the reply I have sent.
Just being honest.

[Driftwood]

I hope it's ok the Ferry is world class. We are lucky to have a place like it.

[stoneflynut]

Originally Posted by Bighand

Leave them alone. Every ones wants wild trout. There they are growing before your eyes.
If they wash down river more food for the Colorado Pike Minnow. Little known fact about this fish is once it reaches 12 inches it eats almost entirely smaller fish. Don't see them cutting their belly open to see how many of their own they have eaten.
Plus they have 10 per cent chance of surviving so their numbers will drop naturally.
I don't have any idea what the river flows are going to be the coming years. There may not be another spawing of wild trout for many years.
I am not sure about this. But, I am pretty sure there is no one running up the river with stocker trout stocking the river every month.
If Game and Fish wants to do something why not bring back the scub population.
Isn't Lee's Ferry one of the Blue Ribbon fishing spots for Arizona?

Unless they were recently stocked, and I doubt they were, there are no Colorado River Pike Minnows (aka squawfish) in the Colorado River below Lees Ferry all the way to Yuma. Dead and gone, they are. Now only found in the Upper Basin, above Lake Powell.

[AGFD_REG_II]

Thank you for all of your comments regarding Lees Ferry. This important Blue Ribbon fishery is a jewel for the state of Arizona and anglers from around the world that enjoy its unique fishing opportunity.

I have not frequented this forum but was recently informed of the discussion regarding the Lees Ferry Fishery. I’m the Regional Fisheries Program Manager for Region II of the Arizona Game and Fish Department. Prior to taking this job, I worked as a fisheries research biologist at Lees Ferry from 1993-2009. I would like to provide some insight and professional opinions to this conversation and welcome all feedback as well as calls or emails to my office.

The Long-term experimental and management Plan for Glen Canyon Dam (LTEMP GCD) WILL HAVE AN IMPACT ON THE TAILWATER FISHERY. This plan will likely direct the management of the GCD for the next 10-15 years. Impacts to the tailwater trout fishery MAY BE POSITIVE OR NEGATIVE because releases from the dam determine the trout carrying capacity of the river along with the health of the trout food base. If the Lees Ferry fishery, or any of the resourses below Glen Canyon Dam, are important to you then it is important that you comment during the scoping period of the LTEMP environmental impact statement (EIS). These comments will help direct the alternatives that will be evaluated during the EIS. The public comment period ends January 31, 2012. NPS and BOR have set up a website as a place for additional information and to send comments. http://ltempeis.anl.gov/.

PLEASE COMMENT ON LTEMP.

Lees Ferry has experienced a series of “boom and bust” years for angling catch rates and length composition. The fishery is characterized by cold water temperatures and a food base that is made up of small lower quality food Items for trout. We have evaluated stomach contents for numerous trout over the years and they live on chironomids (miges), and gammarus lacustris (scuds). Unfortunately there is an extremely low incident of Piscivory (fish eating) among these trout at the Ferry. Because the trout dine on small food items it is difficult to grow large fish unless these food items are extremely abundant and available to fish. A fish can only grow if the calories from food are greater than the energy expended in the pursuit of that food. Imagine me (a fat guy) living in a world where I can only eat cheerios that are spread about the landscape and hidden in the grass. I would not fare well. Small fish on the other hand do quite well during periods when food is less available because they require less of it.

When you combine these general rules of energetics with recent flows you get a pattern emerging with the fishery. During lower water years there is a smaller food base and fewer habitats for fish. When these years are followed by high stable equalization flows as we have seen recently, Food availability increases and we see an extremely healthy fish population characterized by more, larger, fast growing fish that are vulnerable to angling. During these years we generally also see incredible natural recruitment. This past year a research biologist estimated that there are over 1 million small fish in the systems that appear to be surviving and growing. Keep in mind that these small fish are consuming the same resources that are necessary for the growth of larger fish. When the flows are reduced in future years due to less runoff from the upper basin into Lake Powell, these smaller fish will be directly competing with the larger fish. In these situations, it has been our observation that the smaller fish win and we end up with a river that is saturated with small fish.

It is our hope to someday be able to mitigate these cyclic changes by developing tools to control recruitment of rainbow trout in the Lees Ferry reach. This will take some experimentation but may be possible through flow regimes that disadvantage small trout (less than 4 inches) or through mechanical removal of small trout. It is our desire to create a Lees Ferry trout fishery that produces quality fish over a range of flow regimes from the dam. To date there has been no mechanical removal of rainbow trout except near the confluence of the Little Colorado River and the Colorado River (60 miles downstream of Lees Ferry).

The Endangered Humpback chub also lives in the Colorado River. We are required by law to manage the river downstream of Lees ferry for this species along with other native fish species. Rainbow trout may have negative impacts on these species and out-migrant trout from Lees Ferry may be moving downstream to our native fish area. It is hypothesized that most out-migration of trout from Lees Ferry occurs when densities of small fish are extremely high at Lees Ferry. Experiments are ongoing to test this hypothesis.

We are currently in a unique position to enable management of the river such that both native fish and non-native sport fish benefit from upcoming experimentation and management of Glen Canyon Dam. I manage numerous fisheries and am frequently in a position where native fish are pitted against non-native sport fish. This is always a difficult position. I am hopeful that a win/win scenario will be among the alternatives proposed in the upcoming LTEMP for Glen Canyon Dam and that the sport fishery maintains its rightful place amongst the resources managed downstream of the Glen Canyon Dam.

Thank you for your time, please feel free to contact me (via email or phone call, I'm not in a position to debate within the forum), and please make comments on the LTEMP EIS before Jan 31.

ON A SIDE NOTE
As a result of the 2008 high flow experiment ( which provided for a very strong year class) followed by the recent equalization flows (providing more habitat and trout growth potential), preliminary creel results are showing angler catch rates at Lees Ferry as high as they have ever been. 1998 was the last year that catch rates were this high. 1998, at Lees Ferry, was also the only year that I have ever had a 100 trout day on a fly rod (I grew up in Montana and am not a stranger to fly fishing). Go fish the Ferry.

Scott Rogers
Arizona Game and Fish Department
Fisheries Program Manager, Region II, Flagstaff
srogers@azgfd.gov
928 214 1245