Salmonfly reintroduction

[nightfish 0]

Hey everybody,

 

Here's an update from the Cache Anglers (Northern Utah TU chapter) /Utah State University Pteronarcys Californica reintroduction project. If you missed the first thread 6 months ago, here's a link:

 

http://www.flytyingforum.com/index.php?showtopic=6583

 

Brief summary:

The Logan river in northern Utah was once the home of the pteronarcys californica (salmonfly). Populations were very prolific, as recorded by several entomologists. In the 1960's, populations had mysteriously dwindled. By the 70's they were gone from the system. In the last several years, Dr. Mark Vinson, head of the USU Bug Lab took an interest in the mystery, and last summer he presented his studies to the Cache Anglers TU chapter.

 

With the cooperation of Dr. Vinson, Cache Anglers and several government agencies we have undertaken an unprecedented attempt to restore the salmonflies to their home waters. Starting last fall, we began taking nymphs from the adjacent Blacksmith Fork to relocate them in the Logan. This update is for the second of eight biennial transplants.

 

 

On saturday, April 23rd, a group of 50+ volunteers and entomology students gathered on the Blacksmith Fork, with kicknets in hand, to gather as many nymphs as possible in a couple hours time. We collected about 2,500 nymphs of the pteronarcys californica and it's very closely related cousin, pteronarcella badia. On this collection we concentrated on gathering as many large nymphs as possible, hoping they would hatch this spring and oviposit a new generation in the Logan. With early high flows it was a bit difficult to work the most productive riffles, but we had so many people that collection was still productive. THe main collection site was the same as last year, with a smaller group collecting a few miles up the canyon. Dr. Vinson distributed laminated cards for identification by the volunteers, as well as vialed samples of both nymph and adult salmonflies. He and his students positively identified the collected nymphs, and they were placed into aerated coolers containing water from the Logan river.

 

As part of the first collection and relocation, Vinson placed nymphs in three traps to study survival in the Logan. One of the traps was lost, but the other two had good survivability. Two weeks ago, the first three free living nymphs were sampled up from the riverbottom, indicating that the first relocation was successful.

 

Our release site was in a different location than the fall release due to high flows. A spot with calm water adjacent to a run was chosen for this release, with at least 300 yards of riffle below, as well as approximately 50 yards of riffle immediately above the site. Following the release, the volunteers gathered for a barbecue hosted by Cache Anglers.

 

Our next relocation will be this fall, date TBD. For more information, visit the USU project website at:

 

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

[Alex C. 0]

Thats awesome! I hope everything works out for the best. Have they figured out what caused their numbers to fall on the Logan?

[nightfish 0]

The numbers didn't just drop, they completely dissapeared. Here's a link to Dr. Vinson's report last fall, where he discusses some theories on their demise:

 

http://www.usu.edu/buglab/projects/Logan%2...y%20History.pdf

 

To date, we don't know the cause. If the relocation is successful, we'll know there's no longer a problem. If it fails, we hope to find the reason.

[Alex C. 0]

I found your report very interesting, I hope everything goes well, and at the least I hope you can figure out why they dissappeared

[nightfish 0]

Over the past week, the adult salmonflies have appeared on the Blacksmith Fork. Dr. Vinson and his students have spent some time catching adults, and they relocated about 500 to the Logan River. Each female adult lays between 70-500 eggs. Hopefully, this will give some added support to our nymph relocation. You can see a pic of some captured adults at http://www.utahonthefly.com/forums/showthread.php?t=11013

 

Fishing the hatch has been difficult, with warm weather bringing heavy snowmelt, along with very strong rains. Flows are near record levels, and wading is out of the question. Fishing from shore and casting close to the bank has produced a few fish, but action has been slow. Elsewhere around the state...Tooele (pronounced tuh-will-uh) had state record rain yesterday, with nearly 4" in a 24 hr period. Already high water has flooded the town, and some fish have been washed into the streets. Snowbird ski resort, which has been open for business, had to close the lifts yesterday due to too much snow. Draper, in the Salt Lake valley, had extensive flooding, and some homes had as much as 15" in their basements.

 

Our efforts have been noticed around the country, and a short article was published in The Drake magazine. Another article is expected to appear in an upcoming issue of TU's Trout magazine. Hopefully, all this precip & super high streamflow won't scrub out our efforts with the salmonfly relocation.

[nightfish 0]

Latest news!!!

 

Dr. Vinson & crew collected exuvia (shed nymphal skins) from rocks along the relocation areas of the Logan, and found that some of our transplants have hatched into adults!!! WOOHOO!!!

 

Here's a link to the USU Buglab page with info & pictures from the project:

 

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

[Guest]

Congrats on the great outcome so far! That is quite an undertaking and I'm sure you guys are happy to see things coming out good. Hope the good news continues and be sure to keep us posted

[Alex C. 0]

Awesome!