Forum on sockeye runs on Wednesday at Issaquah Hatchery



Submitted by Ray Marcham on Sunday, May 23rd, 02:21pm
The Washington Department of Fish and Wildlife is hosting a public workshop on Wednesday to discuss plans for managing the sockeye salmon runs in Lake Washington and the Cedar River.
A report that WDFW commissioned on the runs will be discussed at the meeting. The report reviewed sockeye populations in Lake Washington and the Cedar, the biological characteristics of these runs and how productive the runs are.
The last recreational sockeye season in Lake Washington was in 2006. The numbers have gone down since.
The meeting will be from 6-8 p.m. at the Issaquah Hatchery, located at 125 W. Sunset Way. WDFW staff will be on hand to discuss the report and answer questions.
http://issaquah.komonews.com/content/forum-sockeye-runs-wednesday-issaquah-hatchery

Anyone going? I live a few minutes away, so maybe I'll pop in. Doesn't hurt that Issaquah Brewhouse is right next door...

So I ended up going to the meeting, so here's a synopsis. Annette Hoffman gave the main presentation, but a few other people of note were there including Doug Hatfield, Bob Everett, and a representative from SPU.

The forum was about this review.

First she went through some background information. Sockeye were introduced in the 1930's to the L. Washington watershed after the Cedar River was diverted. In 1969, the Cedar River escapement goal was 350,000. Now the escapement goal is 350,000 for the entire L. Washington watershed. Sockeye not only spawn in the rivers and tributaries, but also spawn on the beaches.

Data for this review was gathered from WDFW, Muckleshoot, Suquamish, SPU and UW.

The results were as follows: Adult return per spawner is low, this is relative to sockeye stocks in all of the Pacific. Productivity has declined since the 1970's. The hypothesis for the decline in L. Washington sockeye is that the fry are competing with the long fin smelt for food.

The escapement objective still remains at 350,000 adults through the locks (which results in 350,000 in the L. Washington watershed). The report suggests that 102,000 - 227,000 spawners are needed to keep populations at this level. With some conversions, it is suggested that having 140,000 to 311,000 adults passing through Ballard Locks will result in 102,000 - 227,000 spawners reaching their spawning grounds.

The following questions still need to be researched. What is causing low productivity? How are juvenile sockeye interacting with other species in the lake? How accurate is escapement methodology? Can fry survival be improved by delayed release?

They then talked about how policies are set with co-managers and all that.

On to question and answer time.

Is there a difference between wild and hatchery fish mortality rates?
No significant difference.

Have they tried delayed release for sockeye elsewhere?
Don't know. L. Merwin has delayed release of kokanee.

Is Fraser R situation same cause as the situation in L. Washington?
Don't know.

Fry mortality rate?
Smolt data is not precise, no conclusions for cause. The data for smolt exiting the locks is not existent, so can not make a conclusion for comparing mortality rates in L. Washington vs the marine environment.

New hatchery will release up to 34 million fry. (Interim hatchery currently is 17 million maximum.) They will implement techniques to mimic natural conditions. Sockeyes are not held long enough to be really affected by "hatchery conditioning". Currently, they are held 14 days max. If delayed release is considered, they will be held 2 months max. They need to feed on zooplankton out in the open waters. This short period also prevents the hatcheries from giving external markings (missing adipose fin, tag, etc) to differentiate between hatchery and native fish.

The 34 million fry number was produced by estiamting lost spawning grounds above Landburg Dam. They estimated that 262,000 adults could have utilized the waters above the dam, which results in 34 million fry.

Broodstock will be a mix between hatchery and native fish. They want to keep hatchery populations less than half of the overall population (so less hatchery fish than natives).

ratio of returning wild and hatchery fish is highly variable depending on conditions outside of human control.

New hatchery's target for substantial completion is Aug 2011 with broodstock collected that year. WDFW supports this hatchery and this report will not affect the current plans to go proceed.

Proposal by a participant: Tiger Muskies released into L. Washington to control Northern Pikeminnow. In L. Merwin, tiger muskies reduced the population of northern pikeminnow, resulting in an increase of kokanee populations. 90% of predation in L. Washington of sockeye fry are attributed to cutthroat trout and northern pikeminnow. Tiger muskies do not utilize the same areas of the lake as sockeyes do, but tiger muskies do utilize the same areas as squawfish. No significant predation on sockeye.

That's about the gist of it.

Sockeye never got above Landsburg, they were introduced after it went in. The estimate of capacity is based on what could have used the area if it were available.

You're right. I edited the post. Bad handwriting in my notes. Wish i had paid more attention in kindergarten.

A good synopsis Madcapmag, I was there also. I was too lazy to type last evening. I find the idea of introducing Tiger Muskies to be intriguing, especially since they cannot reproduce and become a nuisance in the lake.