Bristol Bay Sockeye Salmon Inriver Test Fishing, 2004

Transcription

1 Fishery Data Series No Bristol Bay Sockeye Salmon Inriver Test Fishing, 2004 y Freerick W. West March 2007 Alaska Department of Fish an Game Divisions of Sport an Commercial Fisheries

2 Symols an Areviations The following symols an areviations, an others approve for the Système International 'Unités (SI), are use without efinition in the following reports y the Divisions of Sport Fish an of Commercial Fisheries: Fishery Manuscripts, Fishery Data Series Reports, Fishery Management Reports, an Special Pulications. All others, incluing eviations from efinitions liste elow, are note in the text at first mention, as well as in the titles or footnotes of tales, an in figure or figure captions. Weights an measures (metric) centimeter eciliter gram hectare kilogram kilometer liter meter milliliter millimeter cm L g ha kg km L m ml mm Weights an measures (English) cuic feet per secon ft 3 /s foot ft gallon gal inch in mile mi nautical mile nmi ounce oz poun l quart qt yar y Time an temperature ay egrees Celsius C egrees Fahrenheit F egrees kelvin K hour h minute min secon s Physics an chemistry all atomic symols alternating current ampere calorie irect current hertz horsepower hyrogen ion activity (negative log of) parts per million parts per thousan volts watts AC A cal DC Hz hp ph ppm ppt, V W General Alaska Aministrative Coe all commonly accepte areviations AAC e.g., Mr., Mrs., AM, PM, etc. all commonly accepte professional titles e.g., Dr., Ph.D., R.N., etc. compass irections: east E north N south S west W copyright corporate suffixes: Company Co. Corporation Corp. Incorporate Inc. Limite Lt. District of Columia D.C. et alii (an others) et al. et cetera (an so forth) etc. exempli gratia (for example) e.g. Feeral Information Coe FIC i est (that is) i.e. latitue or longitue lat. or long. monetary symols (U.S.) $, months (tales an figures): first three letters Jan,...,Dec registere traemark traemark Unite States (ajective) U.S. Unite States of America (noun) USA U.S.C. Unite States Coe U.S. state use two-letter areviations (e.g., AK, WA) Measures (fisheries) fork length mieye-to-fork mieye-to-tail-fork stanar length total length FL MEF METF SL TL Mathematics, statistics all stanar mathematical signs, symols an areviations alternate hypothesis H A ase of natural logarithm e catch per unit effort CPUE coefficient of variation CV common test statistics (F, t, χ 2, etc.) confience interval CI correlation coefficient (multiple) R correlation coefficient (simple) r covariance cov egree (angular ) egrees of freeom f expecte value E greater than > greater than or equal to harvest per unit effort HPUE less than < less than or equal to logarithm (natural) ln logarithm (ase 10) log logarithm (specify ase) log 2, etc. minute (angular) ' not significant NS null hypothesis H O percent % proaility P proaility of a type I error (rejection of the null hypothesis when true) α proaility of a type II error (acceptance of the null hypothesis when false) β secon (angular) " stanar eviation SD stanar error SE variance population Var sample var

3 FISHERY DATA SERIES NO BRISTOL BAY SOCKEYE SALMON INRIVER TEST FISHING, 2004 y Freerick W. West Alaska Department of Fish an Game, Division of Commercial Fisheries, Anchorage Alaska Department of Fish an Game Division of Sport Fish, Research an Technical Services 333 Rasperry Roa, Anchorage, Alaska, March 2007

4 The Division of Sport Fish Fishery Data Series was estalishe in 1987 for the pulication of technically oriente results for a single project or group of closely relate projects. Since 2004, the Division of Commercial Fisheries has also use the Fishery Data Series. Fishery Data Series reports are intene for fishery an other technical professionals. Fishery Data Series reports are availale through the Alaska State Lirary an on the Internet: This pulication has unergone eitorial an peer review. Freerick W. West, Alaska Department of Fish an Game, Division of Commercial Fisheries, 333 Rasperry Roa, Anchorage, AK 99518, USA This ocument shoul e cite as: West, F. W Bristol Bay sockeye salmon inriver test fishing, Alaska Department of Fish an Game, Fishery Data Series No , Anchorage. The Alaska Department of Fish an Game (ADF&G) aministers all programs an activities free from iscrimination ase on race, color, national origin, age, sex, religion, marital status, pregnancy, parenthoo, or isaility. The epartment aministers all programs an activities in compliance with Title VI of the Civil Rights Act of 1964, Section 504 of the Rehailitation Act of 1973, Title II of the Americans with Disailities Act (ADA) of 1990, the Age Discrimination Act of 1975, an Title IX of the Eucation Amenments of If you elieve you have een iscriminate against in any program, activity, or facility please write: ADF&G ADA Coorinator, P.O. Box , Juneau AK U.S. Fish an Willife Service, 4040 N. Fairfax Drive, Suite 300 We, Arlington VA Office of Equal Opportunity, U.S. Department of the Interior, Washington DC The epartment s ADA Coorinator can e reache via phone at the following numers: (VOICE) , (Statewie Telecommunication Device for the Deaf) , (Juneau TDD) , or (FAX) For information on alternative formats an questions on this pulication, please contact: ADF&G, Sport Fish Division, Research an Technical Services, 333 Rasperry Roa, Anchorage AK (907)

5 TABLE OF CONTENTS Page LIST OF TABLES...ii LIST OF FIGURES...ii LIST OF APPENDICES...ii ABSTRACT...1 INTRODUCTION...1 METHODS...2 Inriver Test Fishing...2 Data Analysis...3 In season Evaluation...3 Post Season Evaluation...5 RESULTS...6 Kvichak River...6 Egegik River...6 Ugashik River...7 DISCUSSION...7 ACKNOWLEDGMENTS...9 REFERENCES CITED...9 TABLES AND FIGURES...11 APPENDIX A. DAILY SOCKEYE SALMON INRIVER TEST FISHING DATA...27 APPENDIX B. HISTORICAL INRIVER TEST FISHING DATA SUMMARY BY RIVER...47 APPENDIX C. DRIFT GILLNET CATCHES BY DAY AND SPECIES...51 APPENDIX D. KVICHAK RIVER INRIVER TEST FISHING AND TOWER COUNT DATA, APPENDIX E. EGEGIK RIVER INRIVER TEST FISHING AND TOWER COUNT DATA, APPENDIX F. UGASHIK RIVER INRIVER TEST FISHING AND TOWER COUNT DATA, i

6 LIST OF TABLES Tale Page 1. Locations of Bristol Bay sockeye salmon inriver test fishing projects Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, LIST OF FIGURES Figure Page 1. Major river systems, commercial salmon fishing istricts, an escapement projects in Bristol Bay Comparison of inseason aily sockeye salmon test fish pulishe forecast an lagge oserve escapement, Kvichak River, Comparison of the asolute errors etween the SS Moel ERF an the Pulishe ERF methos, Kvichak River, Comparison of inseason aily sockeye salmon test fish pulishe forecast an lagge oserve escapement, Egegik River, Comparison of the asolute errors etween the SS Moel ERF an the Pulishe ERF methos, Egegik River, Comparison of inseason aily sockeye salmon test fish pulishe forecast an lagge oserve escapement, Ugashik River, Comparison of the asolute errors etween the SS Moel ERF an the Pulishe ERF methos, Ugashik River, LIST OF APPENDICES Appenix Page A1. Sockeye salmon inriver test fishing ata, Kvichak River, A2. Sockeye salmon inriver test fishing ata, Egegik River, A3. Sockeye salmon inriver test fishing ata, Ugashik River, B1. Kvichak River sockeye salmon inriver test fishing ata summary, B2. Egegik River sockeye salmon inriver test fishing ata summary, B3. Ugashik River sockeye salmon inriver test fishing ata summary, C1. Drift gillnet catches y ay an species at the Kvichak inriver test fish project, C2. Drift gillnet catches y ay an species at the Egegik inriver test fish project, C3. Drift gillnet catches y ay an species at the Ugashik inriver test fish project, D1. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D2. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D3. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D4. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D5. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D6. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D7. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, ii

7 LIST OF APPENDICES (Continue) Appenix Page D8. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D9. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, D10. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, E1. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E2. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E3. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E4. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E5. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E6. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E7. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E8. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E9. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, E10. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, F1. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F2. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F3. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F4. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F5. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F6. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F7. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F8. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F9. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, F10. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, iii

8 iv

9 ABSTRACT Drift gillnets were fishe aily at 2 stations, locate on opposite river anks, prior to every high slack tie in the Kvichak, Egegik, an Ugashik rivers, Bristol Bay, Alaska, from mi June to mi July 2004 to estimate sockeye salmon inriver aunance. Fishery managers use test fish preliminary escapement estimates as an inseason management tool to regulate commercial harvests an achieve escapement goals. The aily inriver test fish inex for each river was the mean of catch per unit effort values otaine from all test rifts mae on a given ay. Numers of sockeye salmon that entere the river were estimate using (1) travel time analysis in which the most recent aily tower count was ivie y aily inriver test fish inices an lagge ack in time y aily increments an (2) the mean fish per inex point (FPI) value. Travel time estimates coul not e mae until a minimum numer of aily test fish inices an tower counts were collecte. Mean FPI estimates were availale on the first ay of each project. For the travel time moel, meian FPI for the Kvichak River was 62 with a meian travel time of 2 ; Egegik River meian FPI was 80 with a meian travel time of 1.3 ; an Ugashik River meian FPI was 31 with a meian travel time of 2. Key wors: sockeye salmon, Oncorhynchus nerka, inriver test fishing, inriver aunance estimation, fisheries management, Bristol Bay. INTRODUCTION The Bristol Bay Management Area supports the largest sockeye salmon Oncorhynchus nerka fishery in the worl (Figure 1). The 10-year average ( ) of the total sockeye run to Bristol Bay was 34.4 million fish an total harvest has average 24.2 million fish (West an Fair 2006). Sockeye salmon return to Bristol Bay over a rief time perio an this, comine with the large numers of fish involve, makes it one of the most intense salmon fisheries in the worl. Sockeye salmon in Bristol Bay are manage on an escapement goal range policy, with escapement goal ranges set for iniviual rivers. Fishery managers control the commercial harvest to meet these goals y limiting time, area, an gear use y commercial fishermen. The most important information use y managers to meet these goals is estimates of total fish that have returne to ate. This total return is compose of catch an escapement. Catch estimates are otaine from the processing companies. Estimating the numer of fish that have passe upstream of the fishery is often ifficult, especially once they have move inriver ut have not passe the counting tower. Inriver gillnet test fish projects are use to estimate the numer of fish that passe the commercial fishery ut are still unaccounte for at the tower site, or what is calle estimate river fish (ERF). Inriver test fishery ata are availale approximately 1 ay after sockeye salmon have passe through the commercial fishing istrict an several ays earlier than estimates ase on visual counts from oservation towers locate at the heas of the river systems. Inriver test fish ata assists management iologists in regulating commercial fishing perios to maximize harvests an achieve escapement goals. In 2000 an 2001, monies from the Western Alaska Disaster Grant (WADG) were use to evaluate all inriver test fish projects in Bristol Bay. Evaluation of these projects consiste of examining site location, optimal gillnet mesh sizes, an fishing times. In aition, seasonal factors (e.g., site athymetry, water temperature, water turiity, river ischarge, crew experience, escapement aunance, escapement age composition, an average length of fish in the escapement) were examine to etermine how they affect inriver fish aunance estimates an if they can e use to improve estimates. Accuracy an precision were compare for travel 1

10 time analysis, maximum likelihoo, an regression methos for estimating inriver aunance, using oth aily an cumulative ata. Results suggeste that alternate site locations i not prouce noticealy etter estimates, current mesh sizes were efficient, an rifting shoul occur 15 min sooner than traitional times at Ugashik River (Schwanke et al. 2003). Changes in river athymetry, water turiity, an crew experience were not quantifie, an water temperature ha no ovious affect on test fish results. River ischarge, escapement aunance, an escapement composition (age an average length) were significantly correlate with test fish results at some of the sites. Evaluation an experimentation with moeling proceures suggeste that the travel time metho using cumulative escapement information coul e improve y using aily escapement numers. Inriver test fishing projects have operate at the Kvichak River since 1960, at the Egegik River since 1963, an at the Ugashik River since 1961 (McBrie 1978; Seiel 1965; West 2004). An inriver test fishing project also operate on Igushik River from an Igushik inriver test fish was not operate in 1990 an has not operate since Summary statistics for the Kvichak, Egegik, an Ugashik inriver test fish projects for years are provie in Appenices D, E, an F, respectively. This report summarizes 2004 inriver test fish ata for the Kvichak, Egegik, an Ugashik rivers an evaluates the accuracy of inseason forecasting methos. INRIVER TEST FISHING METHODS Two stations on opposite riveranks were fishe with rift gillnets in the lower sections of the Kvichak, Egegik, an Ugashik rivers (Tale 1). Test fish stations were close to the commercial fishing istrict ounaries an were assume to e aove sockeye salmon milling areas. Station locations for each of the 3 rivers have remaine the same since 1987 (Frie an Bue 1988a). All rifts were mae perpenicular an close to shore ase on the assumption that sockeye salmon migrate parallel to an near the riverank. Drifts at all stations ene when the inshore en of the net rifte aout 25 m offshore or when it was no longer fishing efficiently. Two short rifts of <15 min uration were mae at each station of each river eginning aout 1.5 h efore every high slack tie to minimize currents carrying the gillnet offshore. When catches increase to the point where two rifts per station per tie were ifficult to process given time restraints, only one rift was mae at each station. All gillnets were 45.7 m (150 ft or 25 fathoms) in length an 29 meshes eep. Monotwist we, hung evenly with #50 twine an ye Momoi shae #1, was use for test fishing on all rivers. Multistran monofilament was use until 1989; however, this we type is now illegal for commercial use an is no longer stocke y suppliers. A stretche mesh size of cm (5 in) was use at the Kvichak River an cm (5-1/8 in) was use at the Egegik an Ugashik rivers ecause of ifferences in average fish size. Catch per unit of effort (CPUE), or the numer of sockeye salmon caught in 180 m (600 ft or 100 fathoms) of gillnet fishe for 1 h, was estimate for each set. Water temperature ( o C) was recore at all rivers on every high tie prior to test fishing. 2

11 DATA ANALYSIS In season Evaluation Mean fishing time (MT), in minutes, was calculate for each set as where: (FO - SO)+(FI - SI) MT = SI - FO +, (1) 2 SO = time the gillnet first entere water, FO = time the gillnet was fully eploye, SI = time the gillnet retrieval egan, an FI = time the gillnet retrieval complete. The CPUE value, C j, or the numer of sockeye salmon caught per 100 fathom hours, was calculate for set j as follows: where: N = numer of sockeye salmon caught, an G = gillnet length in fathoms. N C j = 6,000, (2) G x MT The aily inriver test fish inex, I i, for ay i was calculate as the mean of iniviual CPUE values otaine from sets mae the same ay, or where: S = numer of sets mae uring ay i. I i = s j=1 s C j, (3) Two methos were use to estimate aily inriver aunance: (1) travel time (FPI ), an (2) mean FPI value (FPI a ). Travel time of inriver fish was ase on the numer of ays it took sockeye salmon to travel from test fish sites to counting tower sites. A range of travel time estimates was calculate y matching aily test fish inices to aily tower counts. The numer of sockeye salmon represente y each inex point was calculate y iviing the most recent cumulative tower count y cumulative test fish inices lagge ack in time y aily increments such that 3

12 where: FPI = t i=1 t - i=1 E I FPI = numer of sockeye salmon represente y each test fishing inex point ase on a travel time of ays, E i = numer of sockeye salmon traveling past counting tower on ay i, an t = ay of most recent inriver fish aunance estimate. i i, (4) We chose lag that minimize the following sum of squares, SS, etween the cumulative test fish inices an the tower counts where SS = t j = 1 j j 2 ( FPI I i Ei) (5) i= 1 However, travel times that seeme unrealistic ase on results of past stuies or prouce unreasonale escapement estimates (e.g., less than oserve escapement) were rejecte even if they prouce the est statistical fit to the ata. Total inriver fish aunance was calculate as where: t i=1 Eˆ t+ = FPI I i, (6) i=1 E t+ = estimate numer of sockeye salmon that woul travel past counting tower on ay t+. In season, the travel time moel was use to estimate the numer of fish in the river etween the test fishing site an the tower. In practice, however, the estimate numer of inriver fish from the moel was often moifie with ancillary information provie y an area manager, which may have inclue: Fish aunance oserve uring recent aerial surveys; District test fish catch-per-unit effort; an Up-to-the-minute escapements not inclue in the aily moel. In this report, the irect output from the SS moel is terme the travel time moel an the negotiate inriver fish estimate release to the pulic has een terme the pulishe moel. Mean FPI values of inriver fish aunance in 2004 were ase on historic values. For the Kvichak River, 2004 ha a similar run projection of an inshore return an age composition as Therefore, we use the 1999 season ening FPI (FPI=85; Tale 2). For the Egegik an Ugashik rivers, selecte FPI values were ase on years with large runs that ha a high proportion of 2-ocean fish similar to that of 2004 (FPIs of 81 an 65, respectively; Tales 3 an 4). The mean FPI 4

13 estimate of inriver fish aunance is the prouct of the mean FPI an the cumulative inriver test fish inex. Mean FPI value estimates of inriver fish aunance were use until travel time analysis estimates prove more accurate. Post Season Evaluation Three statistics were use to measure performance of the various inriver fish aunance estimators. Percent error, PE, was use to measure aily performance: where: T PE = 100 x - t,a i=1 t+ T t,a = estimate aily inriver fish aunance on ay t ase on metho a. i=1 t+ E i E i, (7) Mean percent error, MPE, was use to measure ias: where: t+ 100 x T - n t,a Ei i=1 MPE =, t+ (8) t=1 Ei i=1 n = total numer of ays that inriver fish aunance estimates ase on test fishing were availale. Mean asolute percent error, MAPE, was use to measure overall accuracy ecause it treate uneran over-estimation errors similarly: t+ T - n t,a E i i=1 MAPE = 100 x t+ (9) t=1 Ei i=1 n To etter unerstan if the use of ancillary information to negotiate the FPI in our pulishe moel was successful in hinsight, an analysis to compare the errors associate with each inriver forecast metho was evelope. Because the true numer of fish etween the test fishing site an tower is unknown, necessary assumptions were use to calculate an actual numer of inriver fish. This was one for travel time an Pulishe moel forecasts y relating the respective inriver estimate to the corresponing lag time from the SS moel output. For example, if a travel time of two applie, the actual numer of inriver fish was calculate y sutracting escapement on ay t+2 minus escapement on ay t. Taking the asolute ifference of the actual escapement an forecasts estimate from travel time or using ancillary information etermine moel errors. 5

14 KVICHAK RIVER RESULTS Test fishing egan 20 June an ene 16 July. A total of 5,200 sockeye salmon were caught, proucing 101,557 inex points (Tale 2; Appenix A1). The 2004 Kvichak River forecast ha a similar run projection of inshore return an age composition as the run in Therefore, the preseason FPI of 85 was ase on the season ening FPI in 1999 an was use through 24 June (Appenix B1). Sufficient spawning escapement ata were collecte y 25 June to allow estimation of FPI values ase on travel time. Estimate travel times uring the season range from 1.0 to 3.0. On the last ay of project operation, the estimate of travel time was 2.0 an the negotiate FPI was 56 (Tale 2; Appenix B1). Meian seasonal travel time was 2.0 an the meian FPI was 62. A complete summary of catch y ay, species an fishing time at the Kvichak River test fish project is presente in Appenix C1. Daily inriver fish aunance estimates ase on aily travel time analysis (25 June 16 July) range from 98% less to 383% greater than oserve tower counts (Tale 2; Figure 2). The final aily travel time analysis estimate of 125,794 sockeye salmon on 16 July ha a percent error of 24% greater than the 2.0 lag tower count of 101,658 (17 18 July). The est performing ERF occurre on 7 July with an estimate 866,843 fish inriver compare to the 1.5 oserve escapement of 870,666 resulting in a percent error of 0% (Tale 2). Accuracy (MAPE) an ias (MPE) for travel time analysis test fish inriver aunance estimates compare to lagge aily tower counts were 84% an 49% respectively. Figure 3 shows the resulting asolute errors for oth the straight travel time an pulishe methos on the Kvichak River. The pulishe forecast provie lower or similar errors than the straight travel time moel. The greatest errors were associate with increase catch rates on 30 June through 2 July an 6 July. EGEGIK RIVER Test fishing egan 14 June an ene 13 July. A total of 2,882 sockeye salmon were caught proucing a cumulative inex of 15,037 (Tale 3; Appenix A2). The preseason calculate mean FPI value of 81, ase on season ening FPIs of large inshore runs with a high 2 ocean age component, was use for test fish inriver fish aunance estimates for June. Sufficient spawning escapement ata were collecte y 21 June to allow estimation of FPI values ase on the travel time approach. Estimate travel times uring this perio using negotiate FPI values range from 1.0 to 2.5. On the last ay of project operation, the negotiate estimate of travel time was 1.0 an the FPI was 86 (Tale 3; Appenix B2). Meian seasonal travel time was 1.3 an the meian FPI was 80. A complete summary of catch y ay, species an fishing time at the Egegik River test fish project is presente in Appenix C2. Daily inriver fish aunance estimates ase on aily travel time analysis (20 June 13 July) range from 93% less to 866% greater than tower counts (Tale 3; Figure 4). The final aily travel time analysis estimate of 12,411 sockeye salmon on 13 July ha a percent error of 202% greater than the 1.0 lag tower count of 4,104 (14 July). The est performing ERF occurre on 6 July with an estimate 159,832 fish inriver compare to the 1.5 oserve escapement of 155,478, resulting in a percent error of 3% (Tale 3). Accuracy (MAPE) an ias (MPE) for travel time analysis test fish inriver fish aunance estimates compare to tower counts were 147% an 115% respectively (Tale 3). For the 6

15 Egegik River, the pulishe forecast provie lower errors than the straight travel time moel from 20 June through 24 June. Thereafter, oth moels followe a similar tren with the greatest errors associate with higher than expecte passage rates at the tower on 29 June an 9 July (Figure 5). UGASHIK RIVER Test fishing egan 22 June an ene 15 July. A total of 1,779 sockeye salmon were caught proucing a cumulative inex of 21,712 (Tale 4; Appenix A3). The preseason calculate mean FPI of 65, ase on season ening FPIs of recent year inshore runs (1999 an 2002) that containe a high 2 ocean age component, was use for test fish inriver fish aunance estimates for June (Tale 4). Sufficient spawning escapement ata were collecte y 29 June to allow estimation of FPI values ase on travel time. Estimate travel times uring this perio range from 1.0 to 8.0 ase on negotiate FPI ata. On the last ay of project operation, the estimate of travel time was 1.0 an the FPI was 30 (Tale 4; Appenix B3). Meian seasonal travel time was estimate at 2.0 an the meian negotiate FPI was 31. A complete summary of catch y ay, species an fishing time at the Ugashik River test fish project is presente in Appenix C3. Daily inriver fish aunance estimates ase on aily travel time analysis (29 June 15 July) range from 97% less to 90% greater than visual counts from towers (Tale 4; Figure 6). The final aily travel time analysis estimate of 16,289 sockeye salmon on 15 July ha a percent error of 21% greater than the 1.0 lag tower count of 13,422 (16 July). The est performing ERF occurre on 7 July with an estimate 155,675 fish inriver compare to the 2.0 oserve escapement of 156,060, resulting in a percent error of nearly 0% (Tale 4). Accuracy (MAPE) an ias (MPE) for travel time analysis test fish inriver fish aunance estimates compare to lagge tower counts were 42% an 9% respectively (Tale 4). For Ugashik River, the pulishe metho provie lower errors than the straight travel time approach, particularly etween 4 July an 6 July. The greatest errors were associate with lower than expecte passage rates on 10 an 11 July (Figure 7). DISCUSSION The Bristol Bay river test fish preseason mean FPIs performe poorly on all rivers in 2004 an, as in the history of the test fish projects, this has typically een the case. The mean FPI value was high for Kvichak an Ugashik rivers an low for Egegik River (Appenices B1 B3). The ifference was most exaggerate on Ugashik River where the preseason mean FPI was 65 an the final FPI was 30 (Tale 4). The preseason FPI of 81 on the Egegik River came closest to its season ening FPI of 86 (Tale 3). The greatest variaility of FPIs using lag time relationships occurre on the Kvichak River where it range from 150 to 50 (Tale 2). Season ening FPI values an travel times are currently use to calculate preseason mean FPIs an were thought to est represent the seasonal FPI an travel time. However, aily an peak run timing fluctuations in FPI values an travel times suggest that an alternative value e use. Meian values for FPIs were relatively close to the season ening for Kvichak an Egegik an virtually ientical for Ugashik (Tales 2 4). Meian values for travel time were the same as season ening for Kvichak an Egegik rivers ut 1 ay longer for Ugashik. For 2005, the preseason FPI value will e calculate using the meian FPI values ut the traitional season ening metho will still e use as a comparison. 7

16 Several factors may have contriute to the large errors associate with the pulishe ERF estimates on the Kvichak an Egegik rivers: 1) suen increases in catch rate an the possile acking out of salmon from the river in the Kvichak River an 2) large surges of fish into the Egegik River. The greatest errors in our ERF estimates on the Kvichak River were associate with a large increase in catch rate. Both moels inicate that travel time an FPI increase when in actuality travel time an FPI remaine the same or roppe causing the moels to overestimate ERF values. Although the aily inriver fish inex increase ecause of the increase of fish inriver, catch efficiency remaine the same. Normally an increase in FPI is oserve an a ecrease in catch efficiency occurs with large passage rates, ut it appears catch efficiency remaine the same throughout the season. Essentially, the same proportion of fish passe the rift sites regarless of how many fish were actually inriver. A high inriver inex of 6,818 on 2 July never prouce a large escapement at the Kvichak River tower as expecte several ays later. This inex was reuce to 2,000 on 6 July to help stailize the moel for the remainer of the ERF estimates. It is uncertain if the ensity of fish that were sample an prouce the high inex on the evening tie eventually acke out of the river or if the rifts just caught an early push of fish with nothing ehin it. Both cases coul have cause the over inflation of the inex. In aition to the traitional rift times uring the 2005 season on the Kvichak River, Alaska Department of Fish an Game (ADF&G) intens to conuct rifts earlier in the tie stage to etermine if fish movement is continuous or peaks at some point uring the tie. This has the potential to provie a etter representation of the actual numer of fish inriver. On the Egegik River, the two greatest errors in ERF estimates were associate with large surges of fish on 26 June an 6 July. On oth occasions, the pulishe moel provie a reasonale ERF with a 1.0 or 1.5 travel time for the first 2 ays ut grossly unerestimate the ERF on the thir ay. The passage at the tower i not slow as quickly as the moel inicate. Both the travel time an pulishe moels inicate that travel time was only 1.0 or 1.5 when in reality it was 2.0 or 2.5 with larger FPI values. Both moels were not ale to etect the large escapement when the moels were locke into a 1.0 to 1.5 travel time. One possile explanation for the unerestimation may have een the large presence of smaller size 2-ocean fish. The Egegik escapement is typically preominantly larger 3-ocean fish ut in 2004, 93% of the fish were 2-ocean. The Egegik inriver test fish project uses 5 1/8 mesh ecause of the typically larger 3-ocean component in the escapement. During high passage rates, the ecrease catchaility of the smaller 2-ocean fish woul reuce the net efficiency an unerestimate aunance. The moels provie aequate estimates for the first 2 ays ut y the thir, the escapement was unerestimate. The traitional travel time moel has generally uner forecaste the ERF when large surges of fish enter the river. Ray Hilorn from the University of Washington has evelope a moel that explores the stanar travel time approach, a ensity-epenent lag time approach, an a temporal lag time approach. The ensity epenent moel accounts for large surges of fish encountere at the test fish site pushing fish alreay inriver quicker to the tower site. The temporal moel assumes that fish travel spee is irectly relate to time (stage of the run). Unlike the stanar travel time moel, the ensity-epenent an temporal moels o not assume that all fish travel at the same spee. For example, a portion of the fish may take 1 ay to travel to the tower where others may take anywhere from slightly more than 1 ay to up to 3 or 4 ays. These moels were teste in 2004 an will continue to e teste in

17 ACKNOWLEDGMENTS I wish to thank the following Alaska Department of Fish an Game, Division of Commercial Fisheries personnel for collecting ata inclue in this report: Chris Clark (Kvichak River test fishing project), Charles Lochner (Kvichak River test fishing project), Bra Russell (Egegik River test fishing project), Dirk Mileton (Egegik River test fishing project), Frank Komarek (Ugashik River test fishing project), an Tor Christopherson (Ugashik River test fishing project). Lowell Fair assiste with inseason ERF estimates an provie eitorial review. REFERENCES CITED Bue, B. G Kvichak, Egegik, an Ugashik escapement test fishing. Pages [In] H. J. Yuen, eitor Bristol Bay salmon test fishing projects. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 72, Juneau. Bue, B. G Kvichak, Egegik, an Ugashik escapement test fishing. Pages [In] D. M. Eggers an S. M. Frie, eitors Bristol Bay salmon test fishing projects. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 117, Juneau. Bue B. G., an C. P. Meacham Kvichak, Egegik, an Ugashik escapement test fishing. Pages [In] H. J. Yuen, eitor. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 65, Juneau. Bue, B. G., S. M. Frie, an W. A. Bucher Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A88-4, Anchorage. Crawfor, D. L., F. W. West, an L. F. Fair Bristol Bay sockeye salmon inriver test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A02-19, Anchorage. Frie, S. M., an B. G. Bue. 1988a. Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A88-14, Anchorage. Frie, S. M., an B. G. Bue Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2K88-11, Anchorage. Gray, D. C., D. L. Crawfor, an J. D. Miller Bristol Bay sockeye salmon spawning escapement test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A99-02, Anchorage. Gray, D. C Bristol Bay sockeye salmon spawning escapement test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A00-28, Anchorage. McBrie, D. N Igushik River insie test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Bristol Bay Data Report No. 67, Anchorage. Meacham, C. P Kvichak, Egegik, an Ugashik insie test fishing. Pages [In] H. J. Yuen, eitor Bristol Bay sockeye salmon test fishing projects. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 56, Juneau. Schwanke, C., F. West, L. Fair, an N. Gove Evaluation of inriver test fishing, Bristol Bay, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A03-21, Anchorage. 9

18 REFERENCES CITED (Continue) Seiel, M. C Test fishing in Bristol Bay, Alaska Department of Fish an Game, Division of Commercial Fisheries, Informational Leaflet No. 67, Juneau. Stratton, B. L Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2K90-05, Anchorage. Stratton, B. L., an D. L. Crawfor Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Fishery Report No , Anchorage. Stratton, B. L., an D. L. Crawfor Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A96-02, Anchorage. Stratton, B. L., an J. D. Woolington Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Fishery Report No , Anchorage. Stratton, B. L., S. M. Frie, an K. A. Rowell Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2K89-08, Anchorage. West, F. W Bristol Bay sockeye salmon inriver test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A03-06, Anchorage. West, F. W Bristol Bay sockeye salmon inriver test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A04-02, Anchorage. West, F.W., an L. F. Fair Aunance, age, sex, an size statistics for Pacific salmon in Bristol Bay, Alaska Department of Fish an Game, Fishery Data Series No , Anchorage. West, F. W., C. J. Anerson, an D. C. Gray Bristol Bay sockeye salmon spawning escapement test fishing, Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A00-36, Anchorage. Yuen, H. J Kvichak, Egegik, an Ugashik escapement test fishing. Pages [In] S. M. Frie, eitor Bristol Bay Pacific salmon test fishing projects. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 153, Juneau. Yuen, H. J., S. M. Frie, an W. A. Bucher Bristol Bay sockeye salmon escapement test fishing. Pages [In] S. M. Frie, eitor Bristol Bay Pacific salmon test fishing projects. Alaska Department of Fish an Game, Division of Commercial Fisheries, Technical Data Report No. 154, Juneau. Yuen, H. J., S. M. Frie, an W. A. Bucher Bristol Bay sockeye salmon spawning escapement test fishing in Alaska Department of Fish an Game, Division of Commercial Fisheries, Regional Information Report 2A88-13, Juneau. 10

19 TABLES AND FIGURES 11

20 Tale 1. Locations of Bristol Bay sockeye salmon inriver test fishing projects. Test Fishing GPS a Coorinates Project Stations Riverank Latitue Longitue Kvichak River 1 West N 59 o ' W 156 o ' 2 East N 59 o ' W 156 o ' Egegik River 1 South N 58 o ' W 157 o ' 2 North N 58 o ' W 157 o ' Ugashik River 1 East N 57 o ' W 157 o ' 2 West N 57 o ' W 157 o ' Note: GPS = Gloal Positioning System. GPS coorinates are generally consiere to e accurate within 17 meters. 12

21 Tale 2. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Kvichak River, Test Fishing Moel Estimates Daily % Error Fishing Historical Mean FPI Travel Time FPI Negotiate FPI c Pulishe Oservation Tower of Time Catch Daily Cum. Estimate Estimate Estimate Inriver Daily Cum. Negotiate Date (min) (no) Inex Inex FPI a Forecast River Fish Lag FPI a River Fish Lag FPI a River Fish Estimate Esc. Esc. ERF 6/ / ,997 7,997 6/ ,997 7,997 6/ ,513 34, / ,624 48,520 50, ,104 6/ , ,399 27,000 3,570 4, / , ,551 10,000 19,290 23, / , ,468 8,000 23,364 47, / ,492 2, , , ,000 4,992 52, /29 e ,951 5, , , ,000 28,038 80, / ,136 10, ,313, ,212,897 1,200, , , / ,563 12, ,172, ,097,700 1,000, , , /02 f ,818 19, , , , , , / ,654 24, , , , ,070 1,084, /04 g ,065 28, , , , ,514 1,314, /05 g ,657 38, , , , ,216 1,630, /06 f, g ,160 51, ,746, ,211,581 1,200, ,680 1,805, / ,376 59, ,539, , , ,016 2,155, /08 g,h ,561 63, , , , ,722 2,754, / ,071 69, , , , ,888 3,298, / ,762 72, , , , ,456 3,691, /11 i ,037 82, , , , ,966 3,983, /12 j ,370 88, , , , ,874 4,211, / ,025 93, , , , ,930 4,644, / ,185 98, , , , ,326 4,993, / , , , , ,080 5,202, / , , , , , ,144 5,331, /17 41,892 5,373,078 7/18 59,766 5,432,844 6/25-7/16 Mean MPE k 49 Meian MAPE k 84 -continue-

22 Tale 2. Page 2 of 2. a c e f g h i j k The preseason FPI of 85 was ase on the season ening FPI in ha a similar run projection of an inshore return an age composition as that which occurre in The preseason FPI of 85 was use through 24 June. Thereafter, FPIs were ase on lag-time relationships. Base on the est fit as etermine y the lowest sums of squares value. Closest to pulishe value ase on input from manager, aerial surveys, an/or passage rates at tower. Oservation towers not in operation. Misse evening rifts on 29 June ecause of a prolem with the outoar motor. Interpolate these ata y repeating Inex values from morning rifts. The expecte numer of inriver fish calculate y the average inex of 6,818 on 2 July was not oserve several ays later at the tower. The aily inex on 6 July was ajuste to a value of 2,000 to help stailize the moel for the remainer of the inriver estimates. Catch rate high on station 2 uring evening rifts. Skippe last rift an interpolate y repeating station 2 inex. Misse Set No.'s 137 through 140 ecause of a prolem with the lower unit on the outoar motor. Use average inex values (9979, 16457, 9240, 10330) from evening rifts on 6 July an morning rifts from 7 July to estimate the ERF for 8 July. Use the average inex values from morning rifts on 7 July an morning rifts on 8 July to estimate the ERF for 9 July an eyon. Only one set of rifts were scheule ecause of tie change over. Use morning rifts from 12 July to estimate evening rifts. Catch rate high on station 2 uring morning rifts. Skippe last rift an interpolate y repeating station 2 inex. MPE = Mean Percent Error, MAPE = Mean Asolute Percent Error. 14

23 Tale 3. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Egegik River, Test Fishing Moel Estimates Daily % Error Fishing Historical Mean FPI Travel Time FPI Negotiate FPI c Pulishe Oservation Tower of Time Catch Daily Cum. Estimate Estimate Estimate Inriver Daily Cum. Negotiate Date (min) (no) Inex Inex FPI a Forecast River Fish Lag FPI a River Fish Lag FPI a River Fish Estim ate Esc. Esc. ERF 6/ ,663 9,663 6/ ,400 12,400 6/ ,377 25,377 25,000 6/ ,286 43,568 45,000 14,718 14,718 6/ ,223 38,777 40,000 16,728 31,446 6/ ,055 34, ,313 35,000 9,132 40,578 6/ , , ,771 90,000 28,968 69, / , , ,826 75,000 55, , / , , ,226 60,000 15, , / , , ,590 30,000 3, , / , , ,772 4,000 3, , / , , ,054 2,000 1, , / ,015 5, , , ,000 30, , / ,473 7, , , , , , / , , ,204 20, , , /29 e , , ,052 60, , , / , , ,907 40,000 34, , / , , ,319 50,000 17, , / , , ,948 15,000 7, , / , , ,126 15,000 3, , / , , ,164 15,000 9, , / ,111 10, , ,162 90,000 10, , / ,554 12, , , ,000 93, , / ,032 13, , , ,000 88, , / , , ,766 80, ,364 1,045, / , , ,792 50, ,614 1,184, / , , ,908 35,000 32,130 1,216, / , , ,292 30,000 11,730 1,228, /12 f , , ,534 20,000 46,578 1,275, / , , ,411 10,000 5,856 1,280, /14 4,104 1,285,062 6/20-7/13 M ean M PE g 115 M eian M APE g 147 -continue-

24 Tale 3. Page 2 of 2. a c e f g A mean FPI of 81, ase on 6 years (1989, 1990, 1995, 1997, 1999, an 2002) with season ening FPIs of large inshore runs with a high 2 ocean age component, was use through 19 June. Thereafter, FPIs were ase on lag-time relationships. Base on the est fit as etermine y the lowest sums of squares value. Closest to pulishe value ase on input from manager, aerial surveys, an/or passage rates at tower. Oservation towers not in operation. Only one set of rifts were scheule ecause of tie change over. Repeate morning inex values from 29 June to simulate evening rifts. Only one set of rifts were scheule ecause of tie change over. Use morning rifts from 13 July to simulate evening rifts. MPE = Mean Percent Error, MAPE = Mean Asolute Percent Error. 16

25 Tale 4. Sockeye salmon inriver test fishing ata summary an comparison to tower counts, Ugashik River, Test Fishing Moel Estimates Daily % Error Fishing Historical Mean FPI Travel Time FPI Negotiate FPI c Pulishe Oservation Tower of Time Catch Daily Cum. Estimate Estimate Estimate Inriver Daily Cum. Negotiate Date (min) (no) Inex Inex FPI a Forecast River Fish Lag FPI a River Fish Lag FPI a River Fish Estimate Esc. Esc. ERF 6/ ,390 16,390 6/ ,227 22,227 22,000 6/ ,341 30,341 30,000 6/ ,980 32,980 30,000 6/ ,610 34,610 25, ,506 6/27 e ,463 36,135 20, ,328 6/ ,168 14,840 15, ,928 6/ , ,494 10, , / ,224 10, , / ,228 5, , / , , / , , / , , / , ,058 1, , /06 f , , ,245 10, , /07 g ,395 3, , , ,000 2,964 8, / ,135 6, , , ,000 35,970 44, / ,634 11, , , , , , / ,699 13, , , , , , / ,624 16, , , ,000 88, , / ,869 18, , , ,000 93, , /13 h ,603 19, , ,804 70,000 73, , / ,174 21, , ,367 35,000 43, , /15 i , , ,289 15,000 19, , /16 13, ,650 6/29-7/15 Mean MPE j 9 Meian MAPE j 42 -continue-

26 a Tale 4. Page 2 of 2. The mean FPI value of 65 was ase on season ening FPIs of recent year inshore runs (1999 an 2002) that containe a high 2 ocean age component. Thereafter, FPIs were ase on lag-time relationships. Estimate river fish is a sujective estimate of fish that have entere the river ut have not passe the counting tower ase on all availale information. c Closest to pulishe value ase on input from manager, aerial surveys, an/or passage rates at tower. Oservation towers not in operation. e Fish caught on 22 June likely passe the tower efore counting egan on 26 June. Remove 22 June rifts for ERF estimates on 27 an 28 June. f Ignore all prior rifts an use the starting mean FPI of 65 an the aily inex of 173 to estimate the ERF For 6 July. Assume 2 ay travel time. g Ignore all prior rifts an use the starting mean FPI of 65 an the aily inex of 2,395 to estimate the ERF for July 7. Assume 2 ay travel time. h Only one set of rifts were scheule ecause of tie change over. Use morning rifts from July 13 to estimate evening rifts. i Misse last set of rifts on the evening of 15 July ecause of a prolem with the lower unit on the outoar motor. Interpolate these ata y using half of the catch from each evening rift on 14 July to estimate inex values for the misse rifts. j MPE = Mean Percent Error, MAPE = Mean Asolute Percent Error. 18

27 19 Figure 1. Major river systems, commercial salmon fishing istricts, an escapement projects in Bristol Bay.