BERING SEA POLLOCK RECRUITMENT. ABUNDANCE DISTRIBUTION AND APPROACH TO FISHERY MANAGEMENT UNDER CHANGING ENVIRONMENT Stepanenko M.A. TINRO-CENTER, VLADIVOSTOK
о.св.лаврентия 6 16 1 17 175 18 о.нунивак 1 м о.унимак 175 17 1 16 1 Fig. 1. Bottom trawl survey station locations in the northwestern Bering Sea (TINRO-center) and EI MWT survey (AFSC) tracklines in the eastern and northwestern Bering Sea Б 64 63 92 91 Fig. 2.. EI MWT survey (TINRO-center) tracklines in the northwestern Bering Sea 1 62 11 13 11 14 15 61 16 1 9 94 93 97 98 95 96 5(27) 99 6(28) 8 7(29) 1(23) 9 2(24) 3(25) 4(26) 6 174 175 176 177 178 179 18 181 179 182 178 183 177 184 176 185 175 W 5 2 1
1 1 5 1 4 1985 1 1 1 1 25 199 6 6 1 1 5 1 5 15 1988 1 1 5 1 5 75 1992 6 6 6 1 1 5 1 5 1 1989 Fig. 3. Pollock eggs (I IV IV stages) distribution in the Bering Sea in 1985-1992, 1992, number/sq. mile. The 2 m depth contour line is indicated as dotted line 1985, April 22 May 31 1988, April 11 May 26 1989, April 11 May 22 199, April 7 June 5 1992, April 13 May 27
66 3 1 3 1 3 1 3 64 63 62 61 6 59 58 57 56 2 m 1 m 54 1 17 175 18 W 185 175 19 17 195 1 2 16 25 1 Fig. 4.. Walleye pollock regular distribution (fish/.5 hour tow) in the Bering Sea in summer-autumn period
66 VII (8-) 64 62 6 IV-V (5-1) III (7-) IV (5-7) V-VI (6-1) 58 V-VII (7-) IV ( 4-6) 56 54-1 - 2 IV (5-1) III (6-1) (7-) III-IV (9-) II-III (5-7) II-III (6-1) III-IV(5-7) I-II (7-) 52-3 1 17 175 18 185 175 17 19 195 1 16 2 Fig. 5. Distribution of spawning concentrations and general direction of prespawning migrations of the Bering Sea pollock (1 - eastern and northwestern Bering Sea, 2 - area off Aleutian Islands, 3 - western Bering Sea). Months of most intensive spawning indicated d by Roman numerals and range of predominant ages of spawning pollock by Arabic numerals. Diameter of the circles reflects relative density of spawning concentrations
64 62 8-6 58-3 5-7 7-1 4-5 1-2 1-1 9-3 - 8 7-1 56 1-1 6-1 7-8 8-5 - 7 54-1 - 2 6-1 7-6 - 1 52-3 1 17 175 18 185 175 17 19 195 1 16 2 Fig. 6. Locations of winter concentrations of the Bering Sea pollock (1 - eastern and northwestern Bering Sea, 2 - area off Aleutian Islands, 3 - western Bering Sea). The range of dominant pollock ages is indicated by Arabic numerals. Diameter of circles reflects relative density of winter concentrations
Fig. 7. Pollock distribution in the Bering Sea, summer-autumn period, 1987 А pollock length 21-4 см, Á Б pollock length 41-6 см, В pollock length > 6 см 6 1 ì À Â 6 6 1 ì 1 ì 16 1 17 175 18 175 17 1 16 1 16 1 17 175 18 175 17 1 16 1
Fig. 8. Pollock distribution in the Bering Sea in spring-autumn period, 1988 А pollock length 25-4 см, Б pollock length 41-6 см, В pollock length > 6 см 6 Á Óñëîâíûå îáîçíà åíèÿ, øò./ àñ.òð.: - ; - 1-1; - 1-5; - 5-1; - 1-1; - 1-2. î.ñâ.ëàâðåíòèÿ 1 ì 16 1 17 175 18 175 17 1 16 1 À Óñëîâíûå îáîçíà åíèÿ, øò./ àñ.òð.: - ; - 1-1; - 1-5; - 5-1; - 1-1; - 1-2. î.ñâ.ëàâðåíòèÿ Â Óñëîâíûå îáîçíà åíèÿ, øò./ àñ.òð.: - ; - 1-1; - 1-5; - 5-1; - 1-1. î.ñâ.ëàâðåíòèÿ 6 6 1 ì 1 ì 16 1 17 175 18 175 17 1 16 1 16 1 17 175 18 175 17 1 16 1
Fig. 9. Distribution of pollock in the Bering Sea midwater in summer-autumn, 1999 A) Pollock length < 2 см; Б) ) 21-4 см; В) ) 41-6 см; Г) > 6 см À Â 6 6 1 ì 1 ì Á Ã 6 6 1 ì 1 ì 16 1 17 175 18 175 17 1 16 1 16 1 17 175 18 175 17 1 16 1
176 178 18 182 184 186 188 19 192 194 196 198 2 22 Fig. 1. Pollock distribution in the eastern and northwestern Bering Sea in summer period, 24, 27-21 гг. 3 3 O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO 3 O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO 4 4 4 64 5 6 24 г. 64 5 6 27 г. 64 5 6 28 г. 63 7 63 7 63 7 8 8 8 62 9 62 9 62 9 1 1 1 61 11 61 11 61 11 6 13 6 13 6 13 14 14 14 59 15 59 15 59 15 16 16 16 58 17 58 17 58 17 18 18 18 57 19 3 57 19 3 57 19 3 2 2 2 56 21 1 56 21 1 56 21 1 22 3 22 3 22 3 23 24 1 23 24 1 23 24 1 54 25 54 25 54 25 26 53 53 178 176 174 172 17 168 166 164 162 16 158 26 26 53 176 178 18 178 182 176 184 174 186 172 188 17 19 168 192 166 194 164 196 162 198 16 2 158 22 176 178 18 178 182 176 184 174 186 172 188 17 19 168 192 166 194 164 196 162 198 16 2 158 22 3 O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO 3 O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO 4 4 64 5 6 29 г. 64 5 6 21 г. 63 7 63 7 8 8 62 9 62 9 1 1 61 11 61 11 6 13 6 13 14 14 59 15 59 15 16 16 58 17 58 17 18 18 57 19 3 57 19 3 2 2 56 21 1 56 21 1 22 3 22 3 23 24 1 23 24 1 54 25 54 25 26 53 176 178 18 178 182 176 184 174 186 172 188 17 19 168 192 166 194 164 196 162 198 16 2 158 22 26 53 176 178 18 178 182 176 184 174 186 172 188 17 19 168 192 166 194 164 196 162 198 16 2 158 22
% 1 8 6 4 2 1 2 3 4 5 6 7 8 9 1 11 13 14 15 16 17 Age Russian EEZ US EEZ Fig. 11. 1. Comparative pollock abundance by age in the northwestern (Russian EEZ) and eastern (US EEZ) Bering Sea in summer autumn in 199-s % Fig..Comparative pollock biomass by age in the northwestern (Russian EEZ) and eastern (US EEZ) Bering Sea in summer autumn in 199-s 1 8 6 4 2 1 2 3 4 5 6 7 8 9 1 11 13 14 15 16 17 Age Russian EEZ US EEZ
Fig. 13. Walleye pollock age composition in the eastern and northwestern Bering Sea (a midwater,, b off bottom) in summer-autumn, 21 % 5 4 3 2 N USA = 442, mln. N NavAr = 957,9 mln. a) % 3 25 2 15 1 N USA = 4946,8 mln. N NavAr = 3358,4 mln. b) 1 5 1 2 3 4 5 6 7 8 9 1+ 1 2 3 4 5 6 7 8 9 1+ Age+ US A NavAr Age+ US A NavAr
3 2 1 Fig. 14. The Bering Sea pollock year-classes strength relative to population biomass (a), female spawning biomass (b), Bogoslof spawning biomass (c), young-of of-the the-year fish abundance(d). 69,1 r =,38,4 1978 198 1982 1984 1986 1988 199 1992 1994 1996 1998 2 22 24 Year 15 1 5 Age 1 pollock abundance (1^9) Total pollock biomass, t (1^6) 3 2 1 3 2 1 69,1 r = -,22,4 Age 1 pollock abundance Total pollock biomass 69,1 r = -,76,4 15 1 5 1978 198 1982 1984 1986 1988 199 1992 1994 1996 1998 2 22 24 1978 198 1982 1984 1986 1988 199 1992 1994 1996 1998 2 22 24 Year Age 1 pollock abundance (1^9) Female spawning biomass, t (1^6) 1978 198 1982 1984 1986 1988 199 1992 1994 1996 1998 2 22 24 Age 1 pollock abundance (1^9) Year 15 Bogoslof spawning biomass, t (1^6) 1 5 Age 1 pollock abundance Bogoslof spawning biomass 3 2 1 69,1 r = -,56,4 39 Young-of-the-year fish abundance (1^9) 26 13 Age 1 pollock abundance (1^9) Year Age 1 pollock abundance Female spawning biomass Age 1 pollock abundance Young-of-the-year fish abundance
Fig. 15. Area-weighted bottom (lower lines) and surface (upper lines) temperatures for the Bering Sea during the NMFS summer botom-trawl surveys (1982-211). Fig. 16. Inter-annual variability of temperature and salinity anomalies in layer 5 m (bottom depth 1-2 m) in the nortwestern Bering Sea (Navarin area) in summer-autumn. Black point expected value of anomaly in 2
2 15 Ths. tonns 1 5 197 75 198 85 199 95 2 25 21 215 Year Russian waters eastwards of 174 E Russian w aters w estw ards of 174 E USA waters Fig. 17. Pollock catch in the Bering Sea, 197-21 211 1 15 Fig. 18. Pollock catch and CPUE in the northwestern Bering Sea (Navarin( area), 1978-21 211 Catch, t 8 6 4 2 78 8 82 84 86 88 9 92 94 96 98 2 2 4 6 8 1 14 Year Catch CPUE Number of days 9 6 3 Number of days, 1^3
Fig. 19. Eastern Bering Sea pollock fishery estimates catch-at at-age age data (in number) for 1991-21 21.. The 2 year-class is highlighted (AFSC data).
% 2 М = 26,26 см % 6 15 5 4 1 3 5 2 1 1 15 2 25 3 35 4 45 5 6 7 Длина, см 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 1 + % 2 15 М = 37,73 см % 6 5 4 1 3 5 2 1 Fig. 2. Northwestern Bering Sea (Navarin area) pollock fishery catch-at-age and length data for the autumn period 29-211 % 1 15 2 25 3 35 4 45 5 6 7 Длина, см 2 М = 35,58 см 15 1 5 1 15 2 25 3 35 4 45 5 6 7 Длина, см % 6 5 4 3 2 1 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 1 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 1 + Возраст, лет
Fig. 21. Stock assessment and TAC adoption in Russia Stock Assessment and TAC adoption in Russia Research for Fisheries Stock Assessment (ecosystem surveys, fishery data, modeling) Special Research Plan Team (Spetsovet) (pollock, salmon, herring, crabs, freshwater stocks, etc.) Laboratory Product (tentative TAC estimation) Regional Fishery Management Council (Local Fishery Administration, Fishery Research Institutes, Mass Media and NGOs, such as Fishing Companies) NGOs Regional Research Advisory Panel (Uchenyi Sovet), followed by Central Research Advisory Panel Public Hearings GOs (Local Fishery Administration, Fishery Agency, Ministry of Nature, Ministry of Agriculture, etc.), Fishing Companies, Fishery Research Institutes, Mass Media, NGOs (Conservation Groups, Fishery Associations, and representatives of local communities, local citizens, etc.) Ecological Expert Group Ministry of Nature selects top experts among scientists, working for Academy of Science, Universities, Research Institutes (including Fishery Research Institutes) Approval of TAC assessment by Fishery Agency
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