First ever Salmonfly Re-introduction

[nightfish 0]

Hey Everybody,

 

Our local Trout Unlimited chapter, Cache Angler's, in association with the Utah Department of Wildlife, the Forest Service, the BLM and Utah State University, has begun a four year study to re-establish a population of Pteronarcys Californica and Pteronarcella Badia, commonly known as the Salmonfly.

 

A quick history:

 

The Cache Valley of northern Utah is home to a few nice trout streams. The two involved in our study are the Logan River and the Blacksmith Fork of the Logan(BSF). Both eventually end up in the Bear River, which winds nearly 400 miles through three states before ending up in The Great Salt Lake. The two rivers (which nearly everyone else outside our arid state would call streams or creeks) are fed by springs and snowmelt, and are high-gradient freestone waters, perfect stonefly habitat, until they reach the valley floor at about 4500 feet above sea level. The drainages are adjacent to each other, separated by a high ridge.

 

In the 1920's, entomologist, J.G. Needham noted that both species were quite common in these waters. In the 60's, the hatches dwindled on the Logan, and the large bugs haven't been present there since the early 70's, although both species are still as abundant in the BSF as they were eighty years ago. In addition, both waters are currently host to several different species of stonefly. Goldens, yellow sallies, little olive stones, even a little black winter stone are among these.

 

Mark Vinson, Director of the Utah State University Bug Lab and entomologist for Team USA Fly Fishing, has studied the missing population for the past decade, and as yet, has not been able to determine the reason for the missing population. The stream is essentially the same in flow and temperature, and even though the road has been rebuilt several times, there is no siltation problem. There is no mine runoff, nor sign of residual toxins from herbicides or pesticides. Most government agencies have been open with their records, with the exception of the Utah Department of Transportation. Even without that missing data, there is no current known reason the big stoneflies shouldn't be in attendance. Vinson placed nymphs from the BSF in traps in the Logan during his ten year study, and they lived for up to a year. All but one trap was vandalized or came up missing, but there was no mortality while the traps were accounted for. The final trap was lost during runoff.

 

At a presentation to Cache Anglers in June of this year, Vinson, in the course of discussing our local hatches, brought the mystery to our attention. He discussed how closely tied these systems are...their confluence is less than 10 miles from the mouths of their respective canyons, and the ridge separating them is as little as a mile wide, with a tributary from each less than 1/4 mile apart over the ridge. He noted that at the confluence the water has poor to nonexistant stonefly habitat, and that the BSF in the valley is usually dewatered during the summer irrigation season, but NOT at high spring flow when the hatch happens. He also pointed out that although they are clumsy fliers, the distance is within the extremes considering the winds that are common in the spring. This is even more likely with the two feeders...atabatic and catabatic winds are known to relocate insects great distances, and up and down mountains. He also discussed the dozens of scenarios that could possibly eliminate the insects, with no evidence supporting any of them.

 

The members of Cache Angler's began wondering if they could be relocated, which quickly led to a movement to gain approval from the concerned agencies. Chris Thomas, Cache Angler's and Utah TU board member, was essential to this process. It was decided to transplant insects twice per year, for a period of four years (the length of maturation for Pteronarcys). Our only restriction was that we could not transport water between the two rivers, since BSF is known to be infected with Whirling Disease, and the Logan is key habitat for the threatened Bonneville Cutthroat.

 

This past saturday, the first relocation took place. With over 40 volunteers and the indespensible help of the USU Bug Lab, we gathered several hundred bugs of mixed age class. These were positively identified by the entomologists, placed in aerated coolers of water from the Logan, and transported to the release site. Traps were set as control populations, and the bulk was released into slow water to prevent them from washing away before having a chance to take shelter. The site was chosen by Vinson for its ideal habitat.

 

Our next relocation will be in April, just before the annual hatch. The April sampling will concentrate on the largest individuals, with the hope that they will hatch immediately and parent the first new generation of Pteronarcys in the Logan River. Relocations in the following years will be done at the same site to improve our slim odds.

 

Here is a link to an article in The Salt Lake Tribune. Thanks are in order to our friend Brett Prettyman for helping us spread the word.

 

http://www.sltrib.com/healthscience/ci_2483961

 

I'd also like to mention another success the Cache Angler's and Utah TU has had a major role in. Spawn Creek, a tiny tributary to the Logan and an extremely important area for the Bonneville Cutthroat, is threatened by grazing. In hopes of preventing siltation by cattle grazing, we fought for buck and pole fencing, and helped raise $80,000 to fund an 80 acre project. The cattlemen fought to prevent this, saying it would set precedent to keep them from their historical range here and elsewhere. We were recently granted a 300 acre parcel, with the project taking place this June, and have taken a major step to keep the Bonneville Cutthroat off the Endangered Species list. This great leap came from the Cache Valley, an agricultural area of about 35,000 residents. It is amazing to me the power of organization, and I would encourage each of you to participate in your local TU and FFF chapters, and help make a difference with your home waters!

[nightfish 0]

Here's a couple of links. The first is a follow-up article by the Salt Lake Tribune, and the second is the USU report by Mark Vinson.

 

http://www.sltrib.com/outdoors/ci_2488714

 

http://www.usu.edu/buglab/projects/project%20Salmonfly.htm

 

The second link has pictures from the outing.

 

 

 

So what do you all think about this project? A good thing? Futile? Muddling with Ma Nature? Any ideas about why they'd dissapear, and for so long?

[Pujic 0]

Hey Nick,

 

That sounds interesting. It's common to hear about the reintroduction of certain fish species into a body of water, but to re-establish a natural food source, well this is the first time I've heard of it. It sounds feasable though.

 

Best of luck and keep us posted,

 

The other Nick

[Guest]

Very interesting indeed. I am very curious as to why they disappeared in the first place as a cause has not been found yet.

 

Is is possible this is a natural occurace in certain streams?

 

Keep us updated on your work, I would love to know if the transplant was successful.

[nightfish 0]

QUOTE (SmallieHunter @ Dec 16 2004, 08:32 PM)

Is is possible this is a natural occurace in certain streams?

Yes, I suppose it's possible. A couple of people asked if we were testing the bugs for diseases or parasites. Vinson said that they do carry diseases, as all organisms do, but it really wasn't a concern. If it was a disease or parasite in the Logan that killed them off, it would have to be specific to the two species, since no other groups were eliminated. After 40 years without a host, the disease/parasite would have perished or adapted to another host. And since the bugs in the Blacksmith are plentiful, it is highly unlikely that anything affected that population beyond a normal, natural rate. Therefore, there would be no concern for a relocated population suffering the same affect. Not to mention that such a scenario would be highly unlikely in such a large system like the Logan.

 

How about a little more background on the ecosystem of the watershed. Maybe we can get some ideas that Mark hasn't thought of?

 

Usage of Logan Canyon over the last 40 years:

 

-Cattle and sheep grazing

-Highway corridor (I-89), open year-round

-USFS campground

-Summer and year-round homes

-Culinary water supply (no treatment plant in the canyon)

-Hydroelectric generation at the mouth of the canyon

-Winter recreation in the headwater areas

-ski resort/x-c trails (no snowmaking)

-snowmobiling

-Hunting, fishing, hiking

-Nature center

-Spelunking

 

More recent usage:

 

-Rock climbing

-Mountain biking

-OHV use (designated and undesignated trails)

 

Blacksmith canyon has the same usage, minus the rock climbing, caving, ski resort and year-round highway (to a point). There is also an elk refuge midway up the drainage. Fewer homes of either type, and less grazing. The refuge has irrigated hayfields for winter elk feed.

 

Both have stable historical flows, although the Logan has more variable temperature changes throughout the day (also historical). The Logan has a steeper gradient and cleaner bottom, while the BSF has a somewhat calcified bottom in spots, and good stretches of slickwater. Neither has geothermal activity that I know of.

 

Flora is similar in both canyons, with more coniferous trees in Logan canyon.

 

Any ideas? While you're thinking about it, take a drive with me up Logan Canyon by going here:

http://www.untraveledroad.com/USA/Utah/Cache/LoganTour?w=36E

Click the up arrow or follow the hotlink that says "would you like to see what's ahead?"

 

Unfortunately, you won't have big orange bugs splatting on the windshield as you follow highway 89 to the Beaver Area.

 

But I'm working on it

[Airhead 0]

QUOTE

So what do you all think about this project? A good thing? Futile? Muddling with Ma Nature? Any ideas about why they'd dissapear, and for so long?

 

I think it's a great idea to give it a try!

 

What about a food source? Is there a particular food item that is critical to juvinile developement missing in Logan? Some species are totally dependent on a specific source of food during certain instars. Is information on the dining habits and availability of forage in Logan been compared?

[nightfish 0]

They eat detritus...the finely broken down organic matter in the stream. At larger stages, they scrape algae off rocks, and at their largest stage they are known to prey on small aquatic invertibrates. The Logan has all of those. Excellent thought though!

 

I'll pass any suggestions to Mark Vinson, so keep 'em coming!

[Guest]

nightfish, my first thoughts would have to center on the effect of runoff from I-89. I would think that a serious examination of the silt from the stream, as oppposed to the water, might give some insight into where the pollution from paving and vehicle traffic ends up. Could it possible that they, given their large size, prey on something the other Stones don't. Something made unhealthy from the effects of civilization?

While we are led to believe that power plants are the reason for Mercury contamination, the tons of mercury from grass fertilizer, animal waste, and vehicle contamination shouldn't be discounted.

[nightfish 0]

Wayne,

 

The Logan has very little sediment. It's a pretty swift freestone, with regular spring runoff. The salmonfly diet is mainly detritus, with a little bit of algae grazing, and only at the last stages of nymph development do they become minor predators. The detritus comes mainly from deciduous leaves, and the trees don't seem to me to be unhealthy...quite lush really. All age classes are found in the same locations, at least by my observations on the relocation day. We collected individuals from roughly a size 16 to size 2, but smaller than that could easily be overlooked (or not there...another question to ask).

 

The highway has seen increased traffic ofer the last 40 years, and has had several improvements. But, since it is a culinary source, it is monitored regularly for known toxins. Perhaps the leaves are absorbing emissions and contaminating that way. It hasn't affected the other users of the foodsource though.

 

I'll pass your thoughts to Vinson. Thanks!