Fraser River Sockeye Fisheries and Fisheries Management - Cohen ...

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ensure the reader does not assume that it is cost-effective and accurate sampling method, or thatthis operation provides reliable estimates of the ‘near-short species composition’. It is a wellknownthat fishwheels have highly variable catchability rates (i.e. sampling efficiencies) that area function of location, water depth, flow rates and circulation patterns, water turbidity, and thespatial distribution of the species sampled. Fishwheels can be considered as useful devices toharvest salmon selectively, apply tags and collect samples, but it is doubtful estimates based onthis sampling device are sufficiently accurate, precise and reliable to ‘adjust’ the figures obtainedby long-standing test fishing operations. Might be better and simply more cost-effective toextend the spatio-temporal range of test fishing to adjust historical records and estimates.LGL Response: The reviewer makes a number of unsubstantiated statements regarding theuse of fishwheels to provide near-shore species composition estimates for the Missionhydroacoustic estimates. The readers are referred to Robichaud et al. (2010) for a detaileddescription of the findings from systematic evaluations of the lower Fraser fishwheels. Todate, efforts to obtain reliable near-shore species composition estimates using gillnet testfishing methods have failed and have not been more cost-effective than fishwheels.Page 77: As noted, mark-recapture operations are conducted to obtain escapement estimates forsome stocks, by tagging of 1% of salmon escapements and then sampling carcasses [supposedly]in proportion to abundance, so as to yield mark-recapture estimates that are within ± 25% of theactual abundance. Unfortunately, no information is presented on typical survey conditions or theavailability of partial enumeration structures. Some with considerable field expertise may findthe report conclusions hard to believe. The report of Schubert and Houtman (2007) cited appearsto focus on some 1998 Fraser River runs, and is not a primary publication subject to strict andimpartial peer review. Additional details and comments should be given on the suitability of themethod in various contexts since.LGL Response: We agree with the reviewer that it would be helpful to have a report on themethods used in recent years. However, the reader should be aware that DFO and the PSCconduct detailed annual reviews of the escapement estimates derived from the markrecaptureoperations. We are not aware of any scientists within DFO or the PSC that haveexpressed serious concerns regarding the reliability of the spawning ground escapementestimates derived from mark-recapture studies.Page 82: The Statement of Work identified (3.15) says that “The Contractor will evaluate thescientific basis for determining escapement targets...”. The authors note that a recent MSCcertification review of Fraser River sockeye (Devitt et al. 2010, incidentally co-authored withLGL staff), required that fishery managers define Limit and Target Reference Points for eachstock management unit. MSC certification guidelines are basically commercial constructsM-20
formulated by NGOs, and do not dictate conservation and management guidelines used by theDFO, which generally comply with or even exceed those proposed by the United Nations(UN/FAO). Still, Limit and Target reference points are commonly used by several national andinternational fishery agencies for assessment and management purposes, but the threshold (orbenchmark) values used by various agencies are not always identical for similarfisheries/species. The authors note the targets used by DFO staff changed over the years, andmust now meet those based on the new Wild Salmon Policy (WSP). The ones being formulatedare apparently described by Holt et al. (2010, or 2009), but the interim guidelines used recentlyare given by DFO (2009b). The latter report was unavailable at the time of this writing, but somethreshold values are given in Table 24 along with illustrations (Fig. 15) of the so-called TotalAllowable Mortality (TAM) rule used to guide DFO management. The TAM rule is similar tosome US fishery management guidelines based on the Magnuson-Stevens Fishery Conservationand Management Act (MSA), with thresholds for maximum fishing mortality and minimumstock size that are functions of productive capacity, biomass levels and allowable exploitationrates.Unfortunately, the TAM rule or ‘interim’ management guidelines used recently by the DFO (i.e.DFO 2009b) are not critically reviewed, but the Table 24 figures are used to determine if DFOmet their minimum escapement goals since 1970 (Fig. 16-20). The report should emphasize thatpast or even interim minimum escapement goals may not be scientifically defensible, at aminimum because of possible (and often hypothesized) changes in habitat capacity over time.This view is supported by that of another peer reviewer who attended the Commission of Inquiryworkshop in late November (Mr. Al Martin) and recommended that the carrying capacity of thesome nursery lakes be re-assessed. Basically, the latest/current escapement goals (minimum ortargets) may be excessive and no longer realistic.LGL Response: There is a wide range of views on whether the latest/current escapementgoals are too high or too low and whether or not these goals are scientifically defensible.DFO has initiated a peer review process for a new set of goals (benchmarks) for eachFraser sockeye conservation unit (CU) (Grant et al. 2010). As indicated in our report, “Thelarge year to year variability in escapement targets makes it difficult to regulate fisheriesand evaluate management performance.” Consequently, we have recommended that“Escapement goals for each CU and run-timing group need to be clearly defined andcommunicated to fishers to facilitate the regulation of fisheries and evaluation ofmanagement performance.”Page 100+: The report section describing the state of the Cultus Lake population is based partlyon the preliminary opinions of Bradford et al. (in prep.), COSEWIC assessments, and ironically,and why some precautionary measures (i.e., SARA Schedule 1 listing) were not implemented.M-21
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Fraser River Sockeye Fisheriesand F
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EXECUTIVE SUMMARY1. Catch Monitorin
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implement harvest rate ceilings to
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Table of ContentsEXECUTIVE SUMMARY
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List of TablesTable 1 Annual estima
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List of FiguresFigure 1 Fraser sock
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Figure 21 Estimates of total catch,
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List of AppendicesAppendix A Statem
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used to (1) estimate catch for each
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FISHERIES HARVESTINGOverview of Fis
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Figure 1 Fraser sockeye marine migr
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Table 2 Summary of available inform
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Table 3 provides the annual estimat
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Table 4 Summary of available inform
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season update teleconference meetin
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Catch Estimation MethodsThe procedu
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catch estimates was detected using
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of precision. The overall rating fo
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1998-00 - No agreements with Sto:lo
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initiation of the AFS Agreements in
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Table 12 Comparison of annual socke
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Table 13 Annual estimates of the ha
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Canadian Commercial FisheriesThe pr
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logbook systems. In addition to the
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Table 15 Fraser River sockeye salmo
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Available catch estimates for the r
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Table 17 Summary of available infor
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anged from less than 100 to over 30
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Washington State Recreational Fishe
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equirements have been applied to se
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salmon were biopsied or tagged with
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Stellako-Late Stuart and 531 Adams)
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FISHERIES MANAGEMENTOverview of Pre
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parents of the recruits). Effective
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within the confidence limits. For e
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Ratio of Return to Forecast5.04.03.
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Ratio of Return to Forecast5.04.03.
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Table 20 Pre-season forecast models
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different from the straight line),
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Prediction ability of ForecastsProp
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Stock MAPEReturn Explainedby Foreca
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test fisheries are analyzed in-seas
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Inputs to the cumulative-normal mod
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eginning of the runs, but by mid-ru
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Median Absolute Percent Error (1997
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variety of hydroacoustic techniques
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enefited from improved technologies
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Post-season estimates of Escapement
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precision achieved was considerably
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m 3 /sec during the sockeye run. Fi
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Escapement TargetsOur evaluations r
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20% of the average of the 4-year se
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Table 24 Low escapement benchmarks
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Table 25 Comparison of post-season
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fisheries have been permitted to ta
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sub-dominant cycle years (e.g., 200
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SummaryLow Escapement Benchmarks (L
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Extent of OverharvestingThe estimat
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2,000,0001,800,000Early StuartCatch
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Cultus Lake Sockeye Recovery Effort
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Figure 23 Number of adult sockeye e
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Recovery ObjectivesIn anticipation
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2008 the escapement estimate was 34
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BRISTOL BAY, ALASKA SOCKEYE FISHERY
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accurate, precise, and timely, (2)
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The Bay is subjected to large tidal
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activity (Bocking and Peterman 1988
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% of total run45%40%35%30%25%20%15%
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Harvest estimation methodsTotal har
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Millions of sockeyeYearFigure 27 Hi
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management structure complements th
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1.5Togiak4.03.5NushagakMillions of
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Millions of sockeye7.06.05.04.03.02
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logical given the dynamics of the r
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1.61.4Number of fish (millions)1.21
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Pre-season forecastsAs noted above,
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8.0y = 0.79x + 1.59R² = 0.417.8Log
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12010080MAPE60402001971-1980 1981-1
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Median percent error (MPE)3020100-1
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Table 28 Average age composition of
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dampeners to reduce surface turbule
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current year’s run is accounted f
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and 1999 Revised Annexes. This inte
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Bristol Bay was in 1997 when there
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upon by managers to determine when
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STATE OF THE SCIENCECatch Monitorin
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2006) due to concerns regarding the
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RECOMMENDATIONS1. DFO needs to ensu
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LITERATURE CITEDAdkison, M.D. and R
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Beacham, T.D., M. Lapointe, J.R. Ca
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CSAS. 2007 Pre-season run size fore
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Evans, D.G., J.B. Browning and B.G.
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Hardie, D.C., D.A. Nagtegaal, K. He
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Pacific Salmon Commission. 1998. Re
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Robichaud, D., J.J. Smith, K. K. En
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Valderrama, D. and J.L. Anderson. 2
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Appendix A Statement of Work.Cohen
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All sectors3.7 The Contractor will
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“State of the Science”. Comment
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3.3 The Contractor will review and
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Appendix BList of requests to DFO b
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DFO Request 15: Recent CSAS documen
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Item Description DateRequestedReque
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Appendix CFirst Nation catch monito
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Table C-1 Summary of information re
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Table C-2 Weekly catch monitoring e
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Table D-1 Summary of information re
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community of Port Renfrew. The area
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IPrecision ( + % of the estimate)10
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Table E-2 Annual Strait of Georgia
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Table E-4 Annual Johnstone Strait e
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Table E-6 Lower Fraser River recrea
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0 would mean that the forecast does
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the general ups and downs of the ob
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Appendix G Graphical representation
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Early Stuart Timing GroupEarly Stua
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Summer-run Timing GroupSummer run7.
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Fraser River Indicator Stocks (list
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Page 246 and 247: Fraser River Indicator Stocks (list
Page 254 and 255: Appendix H Pre-season forecast: sum
Page 256 and 257: ManagementGroup(IndicatorStock)MAPE
Page 258 and 259: ManagementGroup(IndicatorStock)MAPE
Page 260 and 261: Appendix I Methods of In-season Sto
Page 262 and 263: Marine Gillnet Test FisheriesThe gi
Page 264 and 265: Expansion line (x1000)9080706050403
Page 266 and 267: Table I-2 Mean values for purse sei
Page 268 and 269: Figure I-5 Map of test fishing loca
Page 270 and 271: Appendix J The Hydroacoustics progr
Page 272 and 273: An SEF project was secured in 2007
Page 274 and 275: Conservation action Comments Partne
Page 276 and 277: Table K-2 Summary of actions to rec
Page 278 and 279: Table L-1 Catch and escapement of s
Page 280 and 281: Table L-3 Performance criteria of p
Page 282 and 283: Ratio of annual return to the avera
Page 284 and 285: Appendix M Reviewer comments on the
Page 286 and 287: Request #5: Sockeye allocations by
Page 288 and 289: utility of pre-season forecasts. Pr
Page 290 and 291: 3. Are there additional quantitativ
Page 292 and 293: made via tagging and experimentatio
Page 294 and 295: Page 60: The authors make extensive
Page 298 and 299: The reported excerpts from Bradford
Page 300 and 301: (budgets, legal issues, pseudo-cons
Page 302 and 303: REVIEW 3/3Reviewer Name: Dr Sean Co
Page 304 and 305: season forecasts that eventually co
Page 306 and 307: allocation shows "No agreement", an
Page 308 and 309: size.Figures showing errors for pre
Page 310 and 311: Goals can easily generate confusion
Page 312 and 313: Total rows from all these tables be
Page 314 and 315: Exploitation Rate100%90%80%70%60%50
Page 316 and 317: Exploitation RateEarly Stuart90%80%
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