A Comparison of the Performance of Summer Steelhead Smolts Released - PowerPoint PPT Presentation

A Comparison of the Performance of Summer Steelhead Smolts Released at Two Sizes From Wallowa Hatchery Lance Clarke, Mike Flesher and Rich Carmichael Oregon Department of Fish and Wildlife 203 Badgley Hall Eastern Oregon University This work was funded by the United States Fish and Wildlife Service through the Lower Snake River Compensation Program

LSR SRCP P Ob Obje jecti ctives • For eac r each des esignate ted s sto tock, es establish an n ann nnual s sup upply of of brood od fish h capable o e of m meet eting egg gg-tak take e goals. s. • Establish a a to tota tal retu eturn o of adult s summer er steel elhead ead in O Ore regon that at meet eets compen ensati tion g goals. • Rees esta tablish sport a t and t tribal al fisheri eries es. • Minimize e the impacts acts of t the program am on residen ent t stocks of g game e fish. h.

Why a Wh a Siz ize a at Release S Study dy? 1. Older studies were with smaller fish (5.5 – 35 fish/lb.). 2. Regional, stock, and hatchery specific factors have produced variable results in past size at release studies. 3 . Address potential interactions with wild fish from release size.

Size a e at R Relea ease se S Study O y Objec ectives es • Smolts ts grown to to tar target sizes of 5 5 fish/lb. (90 g (90 g) ) or r 4 4 fish/lb. (113 (113 g). ). • Compar are e juven enile e migrati tion c charac acteri eristi tics cs a and passage i indices ces at Lower G er Granite D te Dam. • Determ ermine e differ eren ences ces i in c catch contri tributi tion p pattern erns a and smolt-to to- adult s t survival al. • Compare age e co compositi tion at t retu eturn. • Asse sess ss producti ction effecti ectiven enes ess by c compari aring perf rform rman ance ce measur ures such h as adults prod oduc uced per thous usand nd pound nds of smolts ts releas eased ed. • Compare s stra ray rat rates.

The Grande Ronde River Basin and Associated Hatchery Facilities N LOWER GRANITE DAM 20 0 20 40 Kilometers Washington Oregon Wallow owa a Hatc tche hery Irri rrigon Hatc tche hery

Wallowa H a Hatchery a y and Adult Ladder

Irrigon Fish Hatchery

Wallo llowa H Hatchery A Acclim limatio tion P Pond

Relea ease se Data S a Summar ary Wallow owa S a Stock S Steel eelhead head S Size a at R Relea ease S e Study Target Number Brood Release Number size Coded-wire year dates branded (fish/lb) tagged 5 52,433 29,985 1985 5 May 86 4 55,002 29,749 5 46,571 29,132 1986 25-27 Apr 87 4 50,019 29,123 5 53,448 49,957 1988 24 Apr 89 4 53,021 49,988 5 53,097 50,329 1989 19 Apr 90 4 52,820 49,711 5 57,553 41,089 1990 22 Apr 91 4 53,886 40,938

Relea ease se Data S a Summar ary Wallow owa S a Stock S Steel eelhead head S Size a at R Relea ease S e Study Target size Mean weight Mean Length Brood year (fish/lb) fish/lb (g) (mm) 5 5.4 (84.0) 204 1985 4 3.9 (115.2) 224 5 4.7 (96.9) 214 1986 4 3.6 (124.5) 231 5 5.3 (86.4) 203 1988 4 3.8 (118.2) 223 5 5.3 (85.9) 202 1989 4 4.2 (108.0) 218 5 4.5 (101.0) 212 1990 4 3.9 (116.6) 222

Length Freq equen ency D y Distribution ( (198 989) Wallow owa S a Stock S Steel eelhead head S Size a at R Relea ease S e Study 30 5.3 Fish/lb 3.8 Fish/lb 25 of Fish 20 mber o 15 Numb 10 Nu 5 0 150 175 200 225 250 275 For ork Leng Length (m (mm)

Smol Smolt Passa ssage e at L Lower er G Granite D Dam No significant difference P = 0.972 50 5 Fish/lb 4 Fish/lb Percent of Release 40 30 20 10 0 1985 1986 1988 1989 1990 Br Brood Y Year ear

Migratio Mig ion T Tim imin ing to Lower er Gr Granite ite D Dam 5 Fish/lb 4 Fish/lb 50 1989 No. Detected 40 Percent of Total to Lower Granite Dam 30 10,173 20 10,884 10 0 50 1990 40 14,900 30 12,078 20 10 0 50 1991 40 30 18,030 20 18,141 10 0 15 20 25 30 35 Week eek o of th the e Year ear

Smolt to Smol o Adul ult Sur Survival 42% difference, significant, P = 0.006 5 Fish/lb 4 Fish/lb 1,053 2.0 1,063 891 ed ered 1.5 cover 627 540 680 nt Reco 554 483 1.0 cent R Perce 0.5 224 105 0.0 1985 1986 1988 1989 1990 Br Brood Y Year ear

Stray R y Rate Index 66% difference, significant, P = 0.004 25 5 Fish/lb , n = 199 199 No. Strays / Total Recoveries , n = = 329 329 4 Fish/lb 20 15 10 5 0 1985 1986 1988 1989 1990 Br Brood Y Year ear

Adul ult Pr Prod oduction on C Comp omparison on 12.8% difference, not significant, P = 0.179 Adults Prodced / 1,000 lbs smolts 100 5 Fish/lb 4 Fish/lb 80 60 40 20 0 1985 1986 1988 1989 1990 Br Brood Y Year ear

Catc Ca tch and E Escapem ement Di Distr tribution f for 1 198 989 Brood 5 fish/lb 4 fish/lb Catch (n = 627) (n = 891) % of total % of total Columbia River: Net 28.2 28.5 Columbia River: Sport 13.1 9.3 Deschutes River 5.3 7.1 Snake River and Tributaries 24.9 29.6 Grande Ronde River 10.7 8.1 Ocean 0.0 0.4 Catch Total 82.2 83.0 Escapement Deschutes Trap 4.9 3.9 Wallowa Hatchery 12.9 13.1 Escapement Total 17.8 17.0

Age Compositon of Returns to Wallowa Hatchery No significant difference P = 0.183 N = 5,968 fish 5 Fish per Pound 4 Fish per Pound Age 4 (2-Ocean) Age 4 (2-Ocean) 39.6% 35.6% Age 3 (1-Ocean) Age 3 (1-Ocean) 60.4% 64.4% Brood Years 1985-1990 (excluding 1987)

Similar SAS and SRI Patterns, Why? Some Hypotheses 1. Inconsistent tag sampling rate among years. 2. Older age at return when SAS is higher. 3. When survival is high, smolts that may be predisposed to stray survive at a higher rate. 4. Residualism-varying rates of residualism would influence the SAS calculation and could vary the percentage of outmigrating smolts that are inclined to stray as adults. 5. Adults might stray more when run sizes are large. 6. A spurious correlation.

Summa Summary 1. 1. There e was n no consisten tent t trend i in smolt passage e indices ces or migrati tion timing. 2. 2. Smolt-to to-ad adult survival al was g grea eater i ter in f four o r of five y e year ars a and w was significan cantly b better er over er the five-year ear period for r the fish r releas eased ed a at 4 fish/lb compar ared ed to 5 fish/lb. 3. 3. Number er of adults ts produced ced p per 1,000 l 00 lbs of smolts ts releas eased ed was as grea eater er in four r of five e year ars but w was as n not s significan cantl tly better er over r th the f e five-year p ear peri riod. 4. 4. Large e sized ed smolts ts strayed ed a at a a higher r er rate e in every ery year ar. 5. 5. Catch a and escapem emen ent t distri ributi tion was s similar ar for r all brood year ars. 6. 6. There e was n no differ eren ence ce in mean age c compositi tion of r return rns.

Othe her C Cons onsideration ons Total al Sm Smolt lt Producti ction: A releas ease s e size c e change e to 4 fish/lb mean eans fewer er smolts ts needed ed to reac ach adult t producti ction g goal als. 800,000 000 smolts ts @ 4 4 fish/lb. = 1,136, 136,000 000 smolts ts @ 5 fish/ h/lb. Brood oodstoc ock need eeds can can be e red educed . . Residual alism: Fewer er smal all fish, w which h have e been shown to residual alize, will be releas eased ed. However er, fas aster g er growth r rates es a at 4 fish/lb. may produce ce more e early maturi ring residual al m males es. The effect ect of size a e at releas ease e on survival al may be m mediated ted by the leng ngth of of out outmigration n to o the he oc ocean.