BUILDING A BETTER FISH TRAP

CORY CUTHBERTSON, WDFW „ History of L.Washington sockeye and water projects „ Broodstock collection at the old trap and weir at Cavanaugh Ponds „ Fall 2008 installation and operation of the new floating resistance board weir in Renton, WA „ What we learned in the first year and how we can improve next year

Ballard Locks Interim Sockeye Hatchery

• Established 1991 • 17 million fry capacity • Operated by Washington Department of Fish and Wildlife Long Term Project Goals

„ Increase returns of Cedar R sockeye and provide fishing opportunity for public and tribes „ Avoid or reduce effects on naturally spawning populations Challenges

„ Broodstock collection

‹ ESA listed Chinook

‹ Temporary structure in a volatile river Weir at Cavanaugh Pond

11/6/2006 Why a New Weir in Renton?

„ About a 1/3 of the sockeye spawn below Cavanaugh Pond, limiting broodstock collection. „ The new weir is a resistance board weir, which will be able to withstand higher flows. „ Doesn’t require equipment for installation/removal.

Weir Panel Nomenclature

Results: A better fish trap?

„ ~Same # of eggs from ½ the # of adults into the L. Washington basin „ Installed in 2 days, removed in 4 hours without any heavy equipment Next year we should…

„ Better trap door to target Chinook passage „ New Hatchery

Thanks!

„ Paul Faulds and Gary Sprague, SPU „ Brodie Antipa, WDFW „ Seattle Public Utilities „ Cramer Fish Sciences Questions ?

What’s the Hurry?

The Lake Washington fish flop of 2008

Age Composition Of Females

100 80 60 Hatch 40 NOR 20 0 % Of Sampled Fish % Of Sampled 3-yr 4-yr 5-yr Age At Maturati on

Age Composition In Hatchery & Wild Females Is Comparable

Sockeye introductions and propagation in Lake Washington

From Cultus Lake 1917 1935 1944 23,655 to North Cr. 19,700 fry 96,000 to Cedar R. 1950 5,629 to Issaquah Cr. Fraser R.? 76,000 to Issaquah 1954 53,984 to Issaquah Cr

1900 1910 1920 1930 1940 1950 1960 1937 1942 656,000 to Cedar R. 227,139 to Cedar R. 1,257,000 to Issaquah Cr. 254,298 to Issaquah 567,000 Bear Cr. Cr. 1943 1938 54,530 to Cedar R. 100,000 to Issaquah Cr. 41,761 to Issaquah Cr.

1944 32,012 to Cedar R. Sockeye Return to Lake Washington, (WDFW and MIT data)

800000 600000 400000

Sockeye 200000 0 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 Year