Comparative Survival Study

Transcription

1 Comparative Survival Study SARs and Productivity Presenter: Charlie Petrosky CRSO Workshop September 21,

2 Smolt to Adult Survival Rate (SAR) Goals PATH (1998); NMFS 2000 BiOp: 2% SAR met interim NMFS survival criteria 4% SAR met interim NMFS recovery criteria Snake R. spring/summer Chinook Applied to Snake R. steelhead by analogy NPCC (2004, 2009) F&W Program: 2%-6% SAR, average 4% SAR ESA salmon & steelhead Identify effects of ocean conditions; evaluate & adjust inland management actions 2014 F&W Program & ISAB comments: Investigate goals, examine applicability & biological basis relative to population viability & rebuilding 2

3 SARs & Life Cycle Productivity Snake River spring/summer Chinook and steelhead What levels of SAR are associated with: 1) Population replacement at recent spawner abundance Chinook and steelhead 2) Historical (pre-fcrps) productivity Chinook 3

4 Life Cycle Productivity 1) Viability criteria to achieve low or very low risk of population extinction (ESA recovery or delisting; Interior Columbia Technical Recovery Team-ICTRT 2007): Abundance must exceed Minimum Abundance Threshold (MAT) Intrinsic productivity must be adequate to maintain population at or above MAT Post-harvest recruits to spawning grounds 2) Broad scale recovery goals (e.g., States, Tribes, Subbasin Plans) are higher than simple ESA delisting (e.g., sustainable fisheries) Pre-harvest recruits 4

5 SR Chinook Life Cycle Productivity 1) Viability Criteria: Recent abundance Spring/Summer Chinook natural spawner abundance as % Minimum Abundance Threshold ( brood years) Middle Fork Salmon MPG ~ 33% MAT Grande Ronde/Imnaha MPG ~ 33% MAT ICTRT 2007 Survival Gap Life cycle survival multiplier to meet TRT viability criteria ( brood years; 5% extinction risk) Middle Fork Salmon MPG ~ X Grande Ronde/Imnaha MPG ~ X Post-harvest recruits to spawning grounds --> viability 5

6 Hypothetically, life cycle survival improvement could be in egg-smolt survival rates and/or SARs Little room to increase eggsmolt survival in good habitats (e.g., Middle Fork Salmon MPG) Egg-smolt survival could be increased in degraded habitats (e.g., Lemhi R., some Grande Ronde populations) 6

7 ln(rsg/s) ln(rsg/s) ln(rsg/s) SR spring/summer Chinook life-cycle productivity has been inadequate to maintain spawner abundance at MAT Low SARs low productivity Generally consistent pattern across MPGs All MPGs showed declines in abundance from one generation to the next when SARs < 1% < 1% SAR MFS SFS USR GRIM n = 47 n = 27 n = 44 n = % SAR MFS SFS USR GRIM n = 16 n = 21 n = 23 n = 36 > 2 % SAR MFS SFS USR GRIM n = 8 n = 6 n = 8 n = 12 7

8 ln(rsg/s) ln(rsg/s) ln(rsg/s) SR spring/summer Chinook life-cycle productivity has been inadequate to maintain spawner abundance at MAT Low SARs low productivity Generally consistent pattern across MPGs Observations to date are relevant to & support NPCC SAR objectives SARs > 2% allow population increase (at recent low abundance) SARs < 1% major population declines < 1% SAR MFS SFS USR GRIM n = 47 n = 27 n = 44 n = % SAR MFS SFS USR GRIM n = 16 n = 21 n = 23 n = 36 > 2 % SAR MFS SFS USR GRIM n = 8 n = 6 n = 8 n = 12 8

9 SR Steelhead Life Cycle Productivity Steelhead analytical challenges: Comparatively fewer measures of life cycle productivity Sampling adult spawner abundance more difficult spring spawners during spring runoff More complex life cycle smolts emigrate over 4-5 years (e.g., brood year 2000 produced smolts in ) Calculate weighted brood year SAR to compare with life cycle productivity Comparison of steelhead life cycle productivity and brood year SARs Fish Creek, Idaho (Lochsa R. B-run), BY Rapid River, Idaho (Lower Salmon R. A-Run), BY Pahsimeroi River, Idaho (A-run), BY Wild populations with minimal hatchery influence 9

10 ln(rsg/s) SR steelhead life-cycle productivity has been inadequate to maintain spawner abundance at MAT Low SARs low productivity Fewer observations, but generally consistent results with spring/summer Chinook Observations to date are relevant to & support NPCC SAR objectives SARs > 2% allow population increase (at recent low abundance) SARs < 1% major population declines Steelhead <1% 1-2% >2% n = 4 n = 14 n = 13 10

11 SARs & Life Cycle Productivity Snake River spring/summer Chinook What levels of SAR are associated with: 1) Population replacement at recent spawner abundance 2) Historical (pre-fcrps) productivity Account for density dependence & changing environmental conditions Pre-harvest recruits 11

12 Chinook Life Cycle Productivity Accounting for density dependence and changing environmental conditions R/S decreases as S increases e.g., Chignik Lake, Alaska sockeye recruitment functions from ISAB

13 Chinook Life Cycle Productivity Accounting for density dependence and changing environmental conditions Interior Columbia populations: Ricker function with period effect, pre & post FCRPS completion (Schaller et al. 1999, CJFAS) 18 Snake River populations, 4 MPGs, 1950s 2010 brood years (updated) 3 John Day River populations, 1 MPG, 1950s 2004 brood years Tested for changes in productivity & capacity Pre-harvest recruits to Columbia River (to account for changing harvest patterns) 13

14 Chinook Life Cycle Productivity Accounting for density dependence and changing environmental conditions - Interior Columbia populations: SRI, Survival Rate Index Observed ln(r/s) Expected ln(r/s) where, expected productivity is defined for the period before FCRPS completion (pre-1970) SRI = 0, survival = 100% of expected productivity Strong evidence for increase in density independent mortality (reduced productivity); less evidence for change in capacity SRIs varied with ocean conditions and declined with FCRPS development Survival Rate Index 2.0 Pre-FCRPS Brood year Updated from Schaller, Petrosky & Tinus 2014 CJFAS Snake John Day 14

15 %SAR (upper dam to Col. R.) Survival rate indices Snake R Chinook Life Cycle Productivity & SARs Life cycle survival rates declined to about 13% of Pre- FCRPS productivity Post-FCRPS SRIs: average (-4.2 to -0.4) Snake River Chinook spawner-recruit % % SAR Snake River Chinook 6.0% 4.0% 2.0% %

16 %SAR (upper dam to Col. R.) Survival rate indices Snake R Chinook Life Cycle Productivity & SARs Life cycle survival rates declined to about 13% of Pre- FCRPS productivity Post-FCRPS SRIs: average (-4.2 to -0.4) Snake River Chinook spawner-recruit % SAR Snake River Chinook SARs also varied with ocean conditions and declined with FCRPS development 8.0% 6.0% 4.0% 2.0% %

17 %SAR (upper dam to Col. R.) Survival rate indices Snake R Chinook Life Cycle Productivity & SARs Life cycle survival rates declined to about 13% of Pre- FCRPS productivity Post-FCRPS SRIs: average (-4.2 to -0.4) Snake River Chinook spawner-recruit % SAR Snake River Chinook SARs also varied with ocean conditions and declined with FCRPS development 8.0% 6.0% 4.0% 2.0% Aligning observed SARs and SRIs %

18 SRI Snake R Chinook Life Cycle Productivity & SARs SARs explain majority of variation in lifecycle productivity over this period (smolt years ) Snake River spring/summer Chinook % % 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% s s 1980s s s s SAR to Columbia River 18

19 SRI Snake R Chinook Life Cycle Productivity & SARs SARs explain majority of variation in lifecycle productivity over this period (smolt years ) Expected productivity responses to (preharvest) SARs: SAR % pre-fcrps 2% 34% 4% 70% 6% 105% Results generally consistent with NPCC s 2-6% SAR goal Snake River spring/summer Chinook % % 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% s s 1980s s s s SAR to Columbia River 19

20 SRI SRI SRI SRI Middle Fork Salmon MPG (4 populations, 41 years) Middle Fork Salmon MPG Upper Salmon MPG 0% 2% 4% 6% 8% % 1% 2% 3% 4% 5% 6% 7% SAR to Columbia River -5.0 SAR to Columbia River South Fork Salmon MPG Grande Ronde/Imnaha MPG 0% 2% 4% 6% 8% % 1% 2% 3% 4% 5% 6% 7% SAR to Columbia River -5.0 SAR to Columbia River 20

21 SRI SRI SRI SRI Similarity in responses across Snake River MPGs Middle Fork Salmon MPG Upper Salmon MPG 0% 2% 4% 6% 8% % 1% 2% 3% 4% 5% 6% 7% SAR to Columbia River -5.0 SAR to Columbia River South Fork Salmon MPG Grande Ronde/Imnaha MPG 0% 2% 4% 6% 8% % 1% 2% 3% 4% 5% 6% 7% SAR to Columbia River -5.0 SAR to Columbia River 21

22 %SAR (upper dam to Col. R.) Survival rate indices John Day R Chinook Life Cycle Productivity & SARs Life cycle survival rates declined to about 44% of Pre- FCRPS productivity (vs. 13% for Snake) Post-FCRPS SRIs: -0.8 average (-2.5 to 0.3) John Day River Chinook spawner-recruit % SAR John Day River Chinook 12.0% PIT tag SARs begin in 2000 Aligning observed SARs & SRIs 1% 8.0% 6.0% 4.0% 2.0% %

23 SRI John Day R Chinook Life Cycle Productivity & SARs Fewer SAR estimates, but John Day River spring Chinook SARs in 4-7% range associated with historical levels of productivity 0% 2% 4% 6% 8% 10% 12% s -4.0 Results also generally consistent with NPCC s 2-6% SAR goal -5.0 SAR to Columbia River 23

24 Summary Recent SARs of Snake River wild spring/summer Chinook & steelhead << NPCC 2%-6% SAR goals 24

25 Summary Recent SARs of Snake River wild spring/summer Chinook & steelhead << NPCC 2%-6% SAR goals Recent Snake River Chinook & steelhead SARs inadequate to achieve population replacement at Minimum Abundance Threshold levels 25

26 Summary Recent SARs of Snake River wild spring/summer Chinook & steelhead << NPCC 2%-6% SAR goals Recent Snake River Chinook & steelhead SARs inadequate to achieve population replacement at Minimum Abundance Threshold levels Recent SARs (LGR to LGR) and life-cycle productivity (measured at spawning grounds): Low spawner abundance (~33% Minimum Abundance Threshold) SARs < 1% major population declines SARs > 2% allow for population to increase (at recent low abundance) Populations in good habitat: few other options to improve status 26

27 Summary Density dependence considerations (address ISAB 2015 comments) Historical period with larger escapements and variable harvest rates (1950s to recent) Fitted stock-recruitment functions available for large number of Interior Columbia spring/summer Chinook populations (pre-harvest recruits vs. spawners ~ density dependence) 27

28 Summary Density dependence considerations (address ISAB 2015 comments) Historical period with larger escapements and variable harvest rates (1950s to recent) Fitted stock-recruitment functions available for large number of Interior Columbia spring/summer Chinook populations (pre-harvest recruits vs. spawners ~ density dependence) SARs explain majority of variation in life-cycle productivity for Snake River spring/summer Chinook SARs and life-cycle productivity declined since FCRPS completion Declines associated with FCRPS development; survival varies with ocean conditions SARs in 4-6% range associated with historical (pre-fcrps) levels of productivity Results generally consistent with NPCC 2-6% SAR goals Unlikely to achieve broad-scale recovery without substantial increases in SARs 28

29 29

30 Extra slides 30

31 SARs by MPG %SAR (LGR-GRA) SNK-WCH CWTR-CH GRR-CH IMN-CH SFS-CH MFS-CH USAL-CH %SAR (LGR-GRA) SNKWST CTWR-ST GRR-ST IMN-ST SAL-ST

32 MPG average ln(rsg/s) ln(rsg/s) SARs & Life Cycle Productivity Snake River Chinook 4.0 Chinook ln(rsg/s) vs. SAR Relation apparent between SAR and Rsg/S Generally similar response among MPGs GRIM and SFS MPGs may require higher SARs for replacement at recent abundance SAR (LGR-GRA w/o jacks) Chinook MPG average ln(rsg/s) vs. SAR MFS -3.0 SAR (LGR-GRA without jacks) SFS USR GRIM 32

33 ln(rsg/s) SARs & Life Cycle Productivity Snake River steelhead Relation apparent between SAR and Rsg/S Steelhead ln(rsg/s) vs. SAR Fish Cr. Rapid R. Pahsimeroi Log. (Fish Cr.) Log. (Rapid R.) Populations with older age smolts (Rapid R.) may require higher SARs for replacement Log. (Pahsimeroi) Brood year SAR (LGR-GRA) 33