Relationships between resident and anadromous O. mykiss in Cedar River, WA: Anne Marshall WA Dept of Fish and Wildlife improving the chances for steelhead recovery, or

Current research project- “Genetic relationships among anadromous and non-anadromous O. mykiss in Cedar River and Lake Washington: implications for steelhead recovery planning” Principal investigators- Anne Marshall, Maureen Small, and Steve Foley; WDFW Funded in part by Seattle Public Utilities, Landsburg Mitigation Agreement

Motivation for our study- Steelhead population was declining but rainbow trout appeared to be abundant in Cedar River Previous genetic results for O. mykiss parr above and below the dam Adult and juvenile fish passage at Landsburg Dam was to be completed by 2003, opening up ~18 miles of former steelhead habitat

Managers’ needs – Concerns about extinction risks and obligation to pursue mitigation for dam impacts in Cedar River... What in-basin factors were limiting the success of steelhead? Should artificial production of steelhead be pursued? Would trout above the dam become anadromous once passage was open?

Our premise – Understanding relationships between the co-occurring life-history forms was critical for effective management of steelhead Were steelhead producing the majority of resident fish? Were resident trout of non-local origin and were they creating impacts through interbreeding and competition? If so, were resident fish contributing to smolt production?

Research Goal – “Understand genetic population structure of Cedar River and Lake Washington O. mykiss so that managers can design and implement effective strategies to conserve and recover native steelhead and rainbow trout resources”

Research objectives – Determine genetic relationships between adult steelhead and adult resident O. mykiss in Cedar R. & Lake WA Determine genetic relationships between smolts and potential parent groups Investigate in-depth the genetic relationships between above and below dam populations Estimate extent of O. clarki and O. mykiss hybridization Estimate effective population size if appropriate

Background information and environment –

Special features for this coastal steelhead population – Engineered river and migrational route Large lake basin in migrational route Large sympatric sockeye population Relatively large and apparently adfluvial sympatric cutthroat population Within largest metropolitan area of WA

Cedar River watershed, Puget Sound, WA Map from City of Seattle, Cedar R. Habitat Conservation Plan web site

Physical, migrational barriers for Cedar River steelhead Landsburg Dam, RM 21 Ballard Locks, 1 mi from Puget Sound (ship canal entrance to Lake Washington) Bridge Trolls

Cedar River wild steelhead annual escapement estimates

Cedar River and other O. mykiss populations - plot of genetic distances based on allozyme data from S. Phelps and B. Baker (Cedar River above Landsburg Dam) (Chester Morse Reservoir) (Hatchery exotic rainbow stock)

Methods Fish capture – two year cycle with 50-fish goal per site per year: fish ladder trap at Locks; angling for adults (>30 cm); screw trap for smolts Fin clips and scales Genetic: Sampling: Microsatellite DNA markers; nuclear species markers; possibly mitochondrial DNA markers Genetic population statistics; differentiation metrics; assignment and admixture tests

Populations or groups included in study plan - 1. Steelhead at Ballard Locks 2. Steelhead in Cedar River 3. Cedar R. resident O. mykiss below Landsburg Dam 4. Cedar R. resident O. mykiss above Landsburg Dam 5. Chester Morse Lake O. mykiss 6. Adult O. mykiss in Lake Washington 7. Cedar R. O. mykiss smolts - lower river trap 8. Wild Green River steelhead 9. Hatchery steelhead stock in Green River 10. Resident O. mykiss from Green River Basin 11. Hatchery exotic-origin rainbow trout stocks 12. Cedar R./Lake Washington cutthroat trout (O. clarki)

Sampling results to date - 1. Steelhead at Ballard LocksN=56 (1 from 2003, rest from 1997, ‘98 & ’99 scale samples) 3. Cedar R. resident O. mykiss below Landsburg DamN=53 4. Cedar R. resident O. mykiss above Landsburg DamN=50 6. Adult O. mykiss in Lake WashingtonN=4 7. Cedar R. O. mykiss smolts - lower river trapN=17 8. Wild Green River steelheadN= Cedar R./Lake Washington O. clarkiN=36 (from 2002 and 2003) (and 10 potential O. mykiss/O. clarki hybrids)

Existing samples included in preliminary genetic analyses - Hatchery winter-run steelhead (Chambers Creek stock) from Puyallup River Basin – current substitute for hatchery stock sample (9.) from Green River 11. Hatchery exotic-origin rainbow trout stocks - South Tacoma Hatchery, Spokane Hatchery, Goldendale Hatchery, & Eell Springs Hatchery – all are California-origin stocks

Resident O. mykiss sampled in lower Cedar River in May 2003 for genetic analysis

More sampled fish…

O. clarki from lower Cedar River, where potential inter- specific hybrids (based on phenotype) were also sampled.

Pop./Site Ave. Length cm (N) Ave. Age (range) Steelhead- Ballard locks 72.7 (53) [next Table] (3 – 6) Resident O. mykiss- lower Cedar 35.7 (53) 3.6 (2 – 8) Resident O. mykiss- upper Cedar 24.3 (50) 2.0 (1 – 5) Smolts 18.7 (17) Sampled Fish Size & Age

Age Class W1.1+W % Steelhead Ages – Ballard Locks (N=56) 30 females and 26 males

Microsatellite DNA loci used for preliminary analyses to date - Oki-10Ots-1Omm-1128 One-2Ots-3MOmm-1130 One-18Ots-100Omm-1138A One-102Ots-103Omm-1138B One-114Omy-325Sco-103 One-101Omy-1001Sco-110 One-108Omy-1011Ogo-3

Ongoing - Statistical analyses of microsatellite genetic data Hybrids analysis with nuclear markers Assignment and mixture analysis for smolts and other samples Sampling for year 2 to begin in March or April 2004 Progress report in June 2004