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

More documents

Recommendations

Info

12010080MAPE60402001971-1980 1981-1990 1991-2000 2001-2010Time periodFigure 35 Pre-season forecast performance for all sockeye stocks in Bristol BayAlaska compared across the four most recent decades. MAPE=medianabsolute percent error (see Appendix F for detailed explanation) and isrepresented by the black horizontal lines; gray vertical lines indicate therange in MAPE observed for that decade.Offshore test fishing (Port Moller)A test fishing program has been operating in the Bering Sea ~250 miles southwest of theinner areas of Bristol Bay since the 1970s. The test fishery is offshore of Port Moller,Alaska, and intercepts Bristol Bay bound sockeye about 6-8 days before they reach theirstream of origin. Gillnets (200 fathoms—5 1/8 inch stretch mesh) are set at five stationslocated along a transect from Port Moller to Cape Newenham spaced 10 miles apart(Figure 24). Each year from June 10 to July 10, each station is sampled every day(weather permitting) and catches are converted to catch-per-unit-effort (CPUE) andsummed to form an index of abundance (Flynn and Hilborn 2004). Scale and tissuesamples from the catch provide age composition and genetic-based stock compositionestimates within two to four days of when the fish are sampled at Port Moller; therefore afew days prior to when fish arrive in the fishing districts.The usual forecasting method using Port Moller has been to test the regression (with azero intercept) between the year-end total run (from the cumulative daily index observedin the current year based on a relationship built upon total runs) and the cumulative153
indexes observed in previous years on that date going back to 1987 (when the gillnet andsampling protocol was standardized) (Appendix L). The slope of this regression line thenrepresents the average fish per index (FPI) across years for that day of the run. Thisrelationship improves slightly as the season progresses (Figure 36), but the uncertaintyaround the test fishery forecast is still considered too high to have influence onmanagement (T. Baker, pers. comm.). On average the forecast underestimates total runearly in the season, becomes the least biased around June 30, then begins tounderestimate again (Figure 36), indicating a time trend in the within-season FPI. Onecould have hopes of correcting the forecast based on this pattern, but it fluctuatessignificantly across years. The problems stem from measurement error in the index andfrom changes in the FPI both within season and annually.Several attempts have been made to improve the accuracy of the forecast byreconfiguring how the index is calculated from the catches, accounting for temperatureeffects, and by ad hoc methods for removing size selectivity (e.g., Fried 1985; Flynn andHilborn 2004), but none have proved convincing enough to sway managers. However,recent genetic sampling at the Port Moller test fishery allows stock composition estimatesin-season and provides relative estimates of what is coming to each system in the comingdays (T. Baker, pers. comm.). The addition of stock composition estimates has increasedthe “confidence” of the test fishery information. How much the information is useddepends on how well Port Moller tracts the run during the first part of the season. Forinstance, if a spike in the Port Moller index is followed six days later by a spike ininshore catch, then more confidence is given to how well Port Moller is tracking the runfor that year; likewise, researchers look to see if stock composition estimates at PortMoller tract what is observed inshore. However, no statistical rigor is currently appliedto quantify these relationships.154
Page 2 and 3:
Fraser River Sockeye Fisheriesand F
Page 4 and 5:
EXECUTIVE SUMMARY1. Catch Monitorin
Page 6 and 7:
implement harvest rate ceilings to
Page 8 and 9:
Table of ContentsEXECUTIVE SUMMARY
Page 10 and 11:
List of TablesTable 1 Annual estima
Page 12 and 13:
List of FiguresFigure 1 Fraser sock
Page 14 and 15:
Figure 21 Estimates of total catch,
Page 16 and 17:
List of AppendicesAppendix A Statem
Page 18 and 19:
used to (1) estimate catch for each
Page 20 and 21:
FISHERIES HARVESTINGOverview of Fis
Page 22 and 23:
Figure 1 Fraser sockeye marine migr
Page 24 and 25:
Table 2 Summary of available inform
Page 26 and 27:
Table 3 provides the annual estimat
Page 28 and 29:
Table 4 Summary of available inform
Page 30 and 31:
season update teleconference meetin
Page 32 and 33:
Catch Estimation MethodsThe procedu
Page 34 and 35:
catch estimates was detected using
Page 36 and 37:
of precision. The overall rating fo
Page 38 and 39:
1998-00 - No agreements with Sto:lo
Page 40 and 41:
initiation of the AFS Agreements in
Page 42 and 43:
Table 12 Comparison of annual socke
Page 44 and 45:
Table 13 Annual estimates of the ha
Page 46 and 47:
Canadian Commercial FisheriesThe pr
Page 48 and 49:
logbook systems. In addition to the
Page 50 and 51:
Table 15 Fraser River sockeye salmo
Page 52 and 53:
Available catch estimates for the r
Page 54 and 55:
Table 17 Summary of available infor
Page 56 and 57:
anged from less than 100 to over 30
Page 58 and 59:
Washington State Recreational Fishe
Page 60 and 61:
equirements have been applied to se
Page 62 and 63:
salmon were biopsied or tagged with
Page 64 and 65:
Stellako-Late Stuart and 531 Adams)
Page 66 and 67:
FISHERIES MANAGEMENTOverview of Pre
Page 68 and 69:
parents of the recruits). Effective
Page 70 and 71:
within the confidence limits. For e
Page 72 and 73:
Ratio of Return to Forecast5.04.03.
Page 74 and 75:
Ratio of Return to Forecast5.04.03.
Page 76 and 77:
Table 20 Pre-season forecast models
Page 78 and 79:
different from the straight line),
Page 80 and 81:
Prediction ability of ForecastsProp
Page 82 and 83:
Stock MAPEReturn Explainedby Foreca
Page 84 and 85:
test fisheries are analyzed in-seas
Page 86 and 87:
Inputs to the cumulative-normal mod
Page 88 and 89:
eginning of the runs, but by mid-ru
Page 90 and 91:
Median Absolute Percent Error (1997
Page 92 and 93:
variety of hydroacoustic techniques
Page 94 and 95:
enefited from improved technologies
Page 96 and 97:
Post-season estimates of Escapement
Page 98 and 99:
precision achieved was considerably
Page 100 and 101:
m 3 /sec during the sockeye run. Fi
Page 102 and 103:
Escapement TargetsOur evaluations r
Page 104 and 105:
20% of the average of the 4-year se
Page 106 and 107: Table 24 Low escapement benchmarks
Page 108 and 109: Table 25 Comparison of post-season
Page 110 and 111: fisheries have been permitted to ta
Page 112 and 113: sub-dominant cycle years (e.g., 200
Page 114 and 115: SummaryLow Escapement Benchmarks (L
Page 116 and 117: Extent of OverharvestingThe estimat
Page 118 and 119: 2,000,0001,800,000Early StuartCatch
Page 120 and 121: Cultus Lake Sockeye Recovery Effort
Page 122 and 123: Figure 23 Number of adult sockeye e
Page 124 and 125: Recovery ObjectivesIn anticipation
Page 126 and 127: 2008 the escapement estimate was 34
Page 128 and 129: BRISTOL BAY, ALASKA SOCKEYE FISHERY
Page 130 and 131: accurate, precise, and timely, (2)
Page 132 and 133: The Bay is subjected to large tidal
Page 134 and 135: activity (Bocking and Peterman 1988
Page 136 and 137: % of total run45%40%35%30%25%20%15%
Page 138 and 139: Harvest estimation methodsTotal har
Page 140 and 141: Millions of sockeyeYearFigure 27 Hi
Page 142 and 143: management structure complements th
Page 144 and 145: 1.5Togiak4.03.5NushagakMillions of
Page 146 and 147: Millions of sockeye7.06.05.04.03.02
Page 148 and 149: logical given the dynamics of the r
Page 150 and 151: 1.61.4Number of fish (millions)1.21
Page 152 and 153: Pre-season forecastsAs noted above,
Page 154 and 155: 8.0y = 0.79x + 1.59R² = 0.417.8Log
Page 158 and 159: Median percent error (MPE)3020100-1
Page 160 and 161: Table 28 Average age composition of
Page 162 and 163: dampeners to reduce surface turbule
Page 164 and 165: current year’s run is accounted f
Page 166 and 167: and 1999 Revised Annexes. This inte
Page 168 and 169: Bristol Bay was in 1997 when there
Page 170 and 171: upon by managers to determine when
Page 172 and 173: STATE OF THE SCIENCECatch Monitorin
Page 174 and 175: 2006) due to concerns regarding the
Page 176 and 177: RECOMMENDATIONS1. DFO needs to ensu
Page 178 and 179: LITERATURE CITEDAdkison, M.D. and R
Page 180 and 181: Beacham, T.D., M. Lapointe, J.R. Ca
Page 182 and 183: CSAS. 2007 Pre-season run size fore
Page 184 and 185: Evans, D.G., J.B. Browning and B.G.
Page 186 and 187: Hardie, D.C., D.A. Nagtegaal, K. He
Page 188 and 189: Pacific Salmon Commission. 1998. Re
Page 190 and 191: Robichaud, D., J.J. Smith, K. K. En
Page 192 and 193: Valderrama, D. and J.L. Anderson. 2
Page 194 and 195: Appendix A Statement of Work.Cohen
Page 196 and 197: All sectors3.7 The Contractor will
Page 198 and 199: “State of the Science”. Comment
Page 200 and 201: 3.3 The Contractor will review and
Page 202 and 203: Appendix BList of requests to DFO b
Page 204 and 205: DFO Request 15: Recent CSAS documen
Page 206 and 207:
Item Description DateRequestedReque
Page 208 and 209:
Appendix CFirst Nation catch monito
Page 210 and 211:
Table C-1 Summary of information re
Page 212 and 213:
Table C-2 Weekly catch monitoring e
Page 214 and 215:
Table D-1 Summary of information re
Page 216 and 217:
community of Port Renfrew. The area
Page 218 and 219:
IPrecision ( + % of the estimate)10
Page 220 and 221:
Table E-2 Annual Strait of Georgia
Page 222 and 223:
Table E-4 Annual Johnstone Strait e
Page 224 and 225:
Table E-6 Lower Fraser River recrea
Page 226 and 227:
0 would mean that the forecast does
Page 228 and 229:
the general ups and downs of the ob
Page 230 and 231:
Appendix G Graphical representation
Page 232 and 233:
Early Stuart Timing GroupEarly Stua
Page 234 and 235:
Summer-run Timing GroupSummer run7.
Page 236 and 237:
Fraser River Indicator Stocks (list
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
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 296 and 297:
ensure the reader does not assume t
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%
show all

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

Create successful ePaper yourself

Delete template?

Save as template?