Fraser River sockeye salmon: data synthesis and cumulative impacts

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List of FiguresFigure 2.3-1. Cumulative stress model......................................................................... 10Figure 3.3-1. The conceptual model of the life history of Fraser River sockeyesalmon and potential stressors affecting each life stage.. .......................... 18Figure 3.3-2. Life history of Fraser River sockeye salmon illustrating generalizedmovement patterns among habitats. .......................................................... 19Figure 3.3-3. Flow diagram used to assign the relative likelihood that a particularfactor has made a substantial contribution to the decline of FraserRiver sockeye salmon, based on the answers to the questions used tochallenge the available evidence................................................................ 24Figure 4.1-1. Returns per spawner for all Fraser sockeye stocks combined.. .............. 29Figure 4.1-2. Locations of ocean entry for seaward-migrating juveniles of the 64sockeye salmon populations with time series data on annualabundances of spawners and the resulting adult returns or recruits........... 30Figure 4.1-3. Estimates of long term trends in total life cycle productivity for thefour Fraser sockeye run timing groups, by brood year. .............................. 33Figure 4.1-4. Estimates of long term trends in total life cycle productivity for non-Fraser sockeye stocks, by brood year........................................................ 34Figure 4.1-5. A) Total run size of adult Late-run sockeye salmon from 1977 to2008 with fish fate categorized into total catch, en route loss andspawning escapement................................................................................ 35Figure 4.1-6. Aggregate returns to the Fraser Basin (height of bars),recruits/spawner (line) and stock composition (colours within each bar),for each brood year.. .................................................................................. 37Figure 4.5-1. The proportion of Early Stuart sockeye returning as 5-year old adults.... 74Figure 4.5-2. Time series of the percentage of Fraser River sockeye salmon thatmigrate via the northern diversion (Johstone Strait). Source: PacificSalmon Commission unpublished data. ..................................................... 75Figure 4.6-1. Daily average temperature in the lower Fraser River averagedamong years within two time periods (thick line: 1951-1990; thin line:1991-2010) over the summer months......................................................... 82Figure 4.6-2. Number of years that en route loss by adults exceeded 50% for themajor Fraser River sockeye salmon stocks from 1996-2008...................... 83vii
1.0 Introduction1.1 Project ObjectivesOur work was organized around five objectives: workshop facilitation, data synthesis andintegration, integrative analyses of cumulative impacts based on the ten technical reportscompleted to date for the Commission (the Aquaculture Report is still in progress), quantitativeanalyses of cumulative impacts, and clear communication. Each of these objectives is describedbelow.1. Workshop Facilitation. We organized and facilitated a science workshop (Nov. 30 – Dec. 1,2010) including presentations from all research groups, feedback and discussion from allresearchers and peer reviewers, and interactive discussion of linkages and interactions among allresearch projects. The results of this workshop are summarized in Appendix 6.2. Data Synthesis and Integration. Our first task under this objective was to assemble data onproductivity 4 and stressor metrics from all research projects, through development of a datatemplate sent to all researchers, and assistance to these scientists on organizing their data.. Oncereceived, we then organized these data into an integrated format to support statistical analyses(i.e., a linked database associating productivity indices for different stocks with data on stressorsfrom appropriate locations, stocks, years and time periods). This database was designed to beexpandable in future to include other data sets that were not available in time for this project(e.g., information on aquaculture).3. Integrative Analyses of Cumulative Impacts. We first developed integrative frameworks fororganizing and analysing potential cumulative impacts, based on a life history approach. Oursecond task was to summarize patterns in Fraser Sockeye productivity over time and space, andother indicators relevant to the Fraser sockeye fishery, building on the work of Peterman andDorner (2011) and other Cohen Commission technical reports. Third, we synthesized the keyfindings from all Cohen Commission technical reports (representing over 2400 pages) within4 Salmon biologists calculate total productivity as the number of mature adults produced per spawner. Mature adults(or recruits) are estimated as the number of fish returning to the coast before the onset of fishing. This estimate isderived by working backwards from the numbers of adults that eventually reached the spawning ground, plus anyen-route mortality between the mouth of the Fraser and the spawning ground, plus harvest. The total abundance ofreturning adult Fraser sockeye salmon is a product of the number of spawners in the parent generation times theirproductivity. Biologists also estimate juvenile productivity (fry or smolts per spawner), and post-juvenileproductivity (mature adults per fry or spawner).1
Page 1: April 2011technical report 6Fraser
Page 7 and 8: Stage 2: Smolt OutmigrationWe analy
Page 9 and 10: of multiple stressors and factors,
Page 11 and 12: 4.3.5 Other evidence ..............
Page 13 and 14: List of TablesTable 4.2-1. Evaluati
Page 18 and 19: these integrative frameworks, conve
Page 21 and 22: 2.0 Cumulative Impacts or Effects2.
Page 23 and 24: assumed that there is no potential
Page 25 and 26: classes of stressors. However, if s
Page 27: affected by many stressors over its
Page 30 and 31: examples illustrate this problem --
Page 32 and 33: possibly even negligible component
Page 34 and 35: Figure 3.3-1. The conceptual model
Page 36 and 37: 3.3.3 Life history perspective/appr
Page 38 and 39: additional analyses to gain further
Page 40 and 41: Figure 3.3-3. Flow diagram used to
Page 42 and 43: This project is unusual in its scop
Page 45 and 46: 4.0 Results, Synthesis and Discussi
Page 47 and 48: Peterman and Dorner (2011) have thr
Page 49 and 50: Figure 4.1-3. Estimates of long ter
Page 51 and 52: Figure 4.1-5. A) Total run size of
Page 53 and 54: Figure 4.1-6. Aggregate returns to
Page 55 and 56: o were generally worse during the l
Page 57 and 58: Freshwater predators on juvenile so
Page 59 and 60: copper, iron, mercury and silver).
Page 61 and 62: Several analyses by MacDonald et al
Page 63 and 64: abundances (Sproat, Klukshu, Chilka
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feel reasonably confident in this c
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Nelitz et al. (2011; Table 18) foun
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in the Lower Fraser than other Fras
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stressors. Thus our conclusions hav
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There are many marine predators tha
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assumption that exposure occurs whe
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observations that are then averaged
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Johannes et al. (2011) demonstrate
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“likely” contributor to the ove
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Table 4.4-2. Model specifications f
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Region Variable M1 M2 M3 M4 M5 M6 M
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3. survival rates within key portio
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2011). The thermal limit hypothesis
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Historically, the majority of retur
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salinity. There is much evidence th
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declines (discussed in section 4.2
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There is indisputable evidence of t
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Figure 4.6-2. Number of years that
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correlation was statistically signi
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4.6.7 Key things we need to know be
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al (2010). The combined effect of a
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more likely to suffer en-route and
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Table 4.7-2. Variables included in
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However, an important limitation is
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Alternative PreyVariablesModelsM1 M
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will likely have a high correlation
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5.0 Conclusion5.1 Important Contrib
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Stage 5: Migration back to SpawnWhi
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More specifically, the extended res
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The twelve highest priority recomme
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Life stagefor FraserRiversockeyesal
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6.0 ReferencesAinsworth, L.M., Rout
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Johannes, M.R.S., R. Hoogendoorn, R
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Schaller et al. 2007. Comparative S
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utilized to clarify the full range
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Appendix 2. Reviewer Evaluations an
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the conclusions of the Expert Panel
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Response: Figure numbers have been
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Response: This section has been com
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ased on time or other stocks) to
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them in terms of how changes in spa
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efer to some variable being include
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... (Table xx)". Structures of thes
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Report Title: Fraser River sockeye
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show stronger correlations. Hence,
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Fraser and non-Fraser sockeye popul
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a single database for other researc
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Response: We have removed the itali
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evidence unique to each life stage.
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Report Title: Data Synthesis and Cu
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Response: We have further emphasize
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5. I would also encourage the autho
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events occur, it should be possible
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I don’t have anything to add beyo
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constitutes an exposure to human ac
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3.3.1 has been revised to say “As
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most likely contributors to the rec
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A3.2.1 Integrative quantitative met
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Table A3.3-1. A summary of data set
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ProjectNumber Project Name Variable
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ProjectNumber Project Name Variable
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A3.4 Data PreparationContractor dat
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Table A3.4-2. An example entry in t
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Table A3.4-5. Brood year adjustment
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Table A3.4-7. Example output from t
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Table A3.4-9. The table of contents
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ProjectNumberProject Variable Subse
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Page 206 and 207:
Page 208 and 209:
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The objective of our approach is to
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investigated ecosystems” (Burkhar
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Figure A3.5-1. Flow diagram used to
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multiple stresses simultaneously. T
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Change point analysis of productivi
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Figure A3.5-1. This is an example o
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ecruits for this analysis as we wan
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exclude covariates with limited yea
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Figure A3.5-3. Average chlorophyll
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Status only data setsIn many cases
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The A-series of model sets based on
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with this report given the vast sco
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Table A3.5-5. Example of the model
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categories of stressors. We cannot
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o In some cases it may be the timin
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Appendix 4. Quantitative ResultsA4.
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alance” over time and so this it
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Figure A4.2-3. Stock composition fo
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Figure A4.2-5. Stock composition fo
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A4.3 Multiple Regression ResultsA4.
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Life stage Stressor category Variab
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The results show strong support for
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ModelSet_A4c_VarName M1 M2 M3 M4 M5
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Table A4.3-7. Estimates for all fix
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A4.3.3Analyses by stressor category
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Table A4.3-10. Estimates for all fi
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Model: B4bBrood years: 1969-2001We
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A4.3.4Analysis by regionModel: C4a1
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suggest any underlying mechanism, b
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Model: C1a1996-2004For 1996-2004, i
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Table A4.3-23. SoG C1a candidate mo
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Appendix 5. Data Template User Guid
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Metric Connected to Biologically-su
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Initial Conceptual Model (Worksheet
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Commentsopen again. It is acceptabl
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Appendix 6. Workshop Report 1 (Nov.
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Table of ContentsTable of Contents
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PresentationsProductivity Dynamics
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and scope for improvement, particul
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Workshop participants pointed out t
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o Can you find the same shared tren
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generally better for Alaska sockeye
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Relative Likelihood of Alternative
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There was widespread agreement with
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Appendix A: List of Projects and In
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Peer Reviewers: Provide constructiv
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MacDonald Environmental Sciences Lt
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Appendix C: Workshop MinutesContent
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Levy urged researchers to bear in m
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within-population, within-brood-yea
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To address potential skepticism ove
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instead of migrating directly out i
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considered a good surrogate of temp
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Bristol Bay review: There are subst
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Method: The approach included formu
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Staley: Our project needs to compar
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Levy: It will go ahead in January.
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preliminary assessment of potential
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MacDonald: We’re waiting for all
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including Shuswap and North Thompso
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and biological variables. The combi
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temperatures. Notably, it doesn’t
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Seasonal population distribution pa
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Information gaps: The most importan
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Fraser sockeye salmon habitat analy
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survey data, but they were looking
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was also shown that tagged fish ret
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English: There was extensive holdin
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periods showed that 4 to 6 stocks (
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Q/A: Researchers should also feel f
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Peterman: We’re lacking the big p
Page 362 and 363:
Appendix D: Table of likelihood/ hy
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