The Sea of Okhotsk: some conceptions applying to climate-oceanography events and fish resources

Transcription

1 The Sea of Okhotsk: some conceptions applying to climate-oceanography events and fish resources Sen Tok Kim Sakhalin Scientific Research Institute of Fisheries & Oceanography (SakhNIRO)

2 Circulation system in the North Pacific, 1 Alaskan Gyre, Western Subarctic Gyre, 3 Bering Subarctic Gyre, 4 Okhotsk Subarctic Gyre. Currents: 5 Alaskan, 6 East Kamchatka, 7 West Kamchatka, 8 Soya, 9 Oyashio, 1 Kuroshio, 11 Subarctic, 1 North Pacific (Ohtani, 1991)

3 The Sea of Okhotsk cyclonic Gyre in the warm period (July-September) (Chernyavskyi et al., 1993) Oyashio East Kamchatka Currents 1-West Kamchatka -Northern 3-Median 4-Penzhinskoye 5-Yamskoye 6-North Okhotsk 7-North Okhotsk Counter 8-Amur 9-East Sakhalin 1-East Sakhalin Counter 11-North-Eastern 1-Soya Soya 3

4 ice cover, sea area 1 5 Average ice cover in March (JMA, 1991): 1 - >9 of probability, - 7-9, 3 3-7, 4 1-3, 5 - <1 The Sea of Okhotsk: ice cover (), surface air and bottom water temperature T 15 m, C Febrary March March T15 m Линейная (Febrary March) A ir T e m p e ra tu re ( C ) Ice cover averaged in February-March and bottom water temperature averaged for depth 15- m in July (Zhigalov, Luchin, 1; Figurkin, 6) Air temperature anomaly in October-March over northeastern Eurasia (red) and annual sea ice extent anomaly in the Sea of Okhotsk (February)(blue)(Ohshima et al., 6). 4 Sea ice extent (x1 km)

5 Water transport of the Western Kamchatka Current (Northern Branch) within the - m layer in April (Figurkin et al., 8) ice cover, sea area T 15 m, C Febrary March March T15 m Линейная (Febrary March) Warm year transport Cold year transport 5

6 Annual mean discharge of Amur River (red lines) and sea ice area over the Okhotsk Sea (blue lines). The lines are smoothed (3-year average) (Tachibana, Ogi, 9 (1)) Long-term discharge from Amur River (Novorotskii, 7 ()), below Seasonal variation of Amur River discharge discharge, m3/s month 1 6

7 Waters temperature anomalies at South Kuril Islands area in , June-October (Shatilina, 1996) (1), in 198-7, March (Zhigalov, 1)() Surface T HMS Yuzhno Kurilsk HMS Kurilsk Annual mean discharge of Amur River (red lines) and sea ice area over the Okhotsk Sea (blue lines). The lines are smoothed (3- year average) (Tachibana, Ogi, 9). Bottom T

8 Annual mean discharge of Amur River (red lines) and sea ice area over the Okhotsk Sea (blue lines). The lines are smoothed (3-year average) (Tachibana, Ogi, 9). 1,8,6,4,,,4,6,8 1 Temperature, C Temperature anomaly in Bussol Strait area in (Muktepavel, Shatilina, 7). Oceanic coast of Ithurup Island Bussol Strait

9 1,6 Sea surface temperature in the Okhotsk Sea in spring (left) and summer (right)(glebova et al., 9). 9 surface tamperature, C,8 Western Kamchatka surface temperature, C 8,5 8 Western Western Kamchatka Kamchatka 7, ,5 9, surface temperature, C Northern area,5 surface temperature, C 8,5 Northern area 7, surface temperature, C 1 Southern area surface temperature, C 9 Southern area Warming in 198-early199, cooling in -, warming after 3 9

10 The Pacific Decadal Oscillation (PDO) The Pacific Decadal Oscillation (PDO) warm phase cool phase Forecast to the future decade cooling, may be by soft type

11 The atmospheric centers of action Long term trends in the change in repeatability of atmospheric processes over the Okhotsk Sea and ice cover in the cold season (October March) from 1974 to 7 (Glebova et al., 9). Forecast to the future decade cooling, but by soft type 11

12 Present status and forecasting In the 1s, the overall warming of the Okhotsk Sea waters, at least the northern area, is suggested by many processes such as reduced ice cover, increase in average values of SST over the sea, increase in Amur River runoff, and some other less noticeable processes. In the s, apparently, some cooling should be expected (Khen et al., 8, Ustinova et al., 4, Glebova, 7). 1

13 Fisheries impact: long-term trends of annual catches of Sakhalin-Hokkaido herring (1) and Terpeniye Bay s yellowfin sole () thousand ton Fishery prohibition resource catch 13 Annual catch, thousand tons

14 Annual catches of walleye pollock in the Sea of Okhotsk: 1-Total Sea (with Hokkaido area), -Northern Okhotsk Sea, 3-Western Kamchatka, 4-Eastern Sakhalin (below South Kuril and adjacent waters), Walleye pollack (Sea of Okhotsk) 1 1,5 Catch, mln.tonn 1,,

15 Some quantitative aspects of the Sea of Okhotsk for 198-th by total fishes biomass=35 mln. ton, year's production=17.5 mln. ton (Shuntov et al., 1997) Biomass and production of the main groups organisms in the Sea of Okhotsk in 198th The hydrobiont's group Вх1 6, ton Рх1 6, ton Phytoplankton Bacterial plankton - 5 Protozoa - 1 Non-predator zooplankton Predator zooplankton Non-predator zoobenthos 8,6 318 Predator zoobenthos 1,4,1 Pelagic fish 31,5 15,7 Demersal fish 3,5 1,7 Bottom invertebrate 1,5,5 Squids 7 Marine birds,1,4 Mammal,5,1 15

16 Fish species biomass ratio in pelagic communities of the northern Sea of Okhotsk in the last 198s, early 199s, last 199s (Shuntov et al., 1997), 1 walleye pollock, herring, 3 - others Last 198s 1,1 93, 4,9 9,7 14,3 9,3 85,5,1 99, 9, 18, 7,4 9, 4, 1, 9 81, 3,3 78, 1, 94, 5 3,3 Early 199s 9,4 84, 3 8,3 5,9 43,3 1,3 53,9 11, 5,8 44,8 81,6 7,4 3, 7 8,8 46, 3 53, 7 15,5 Last 199s 4, 6,8 89, 1,3 4,1 85,6 3,6 1,5 77,7 78,5 18,7 13, 7 1,6 3,9 67,5 66, 3 19, 9 35, 3 54, 3,4 1,1 98, 5 1, 4 Biomass x1 tons 16

17 Composition and biomass of epipelagic fish communities in the Sea of Okhotsk (Dulepova, Merzlyakov, 7) biomass, thousand ton biomass, thousand tons Walleye pollack Pacific herring Pacific Capelin Other fish Salmons Northern smoothtongue Japaneese anchovy Other fish Northern Okhotsk Sea Southern Okhotsk Sea Annual catches of Japanese sardine in (Belayev, 3) Catches, ton Japanese sardine Japanese fishery area The Sea of Okhotsk South Kuril Islands Pacific Ocean 17

18 Annual abundance and biomass of walleye pollack spawning stock in the northern Okhotsk Sea (Ovsyannikov, 9) Abundance, bln. Ind , , 1987, 1988, Biomass, mln. tons Abundance, bln. ind. Biomass, mln. tons Prevailed generation 1988 Abundant generation 18

19 Annual catches of Pacific herring in the far-eastern seas (Naumenko, 7) Okhotsk stock Korf-Karaginsk stock Eastern Bering Sea stock Gizhiginsk-Kamchatka stock Sakhalin-Hokkaido stock Others Okhotsk stock Annual dynamics of resources of Okhotsk herring in (5-years smoothing) 19

20 Regular bottom trawl surveys areas in the Sea of Okhotsk 6 55 Amur water Kamchatka Peninsula 5 Sakhalin Island Sea of Okhotsk East Kamchatka Current 45 Soya Current Hokkaido Island Oyashio Current Pacific

21 Annual biomass of cottid-fishes (1), gadid-fishes (), flat-fishes (3), and all demersal fish (4) on west Kamchatka shelf, thousand ton (Ilyinskiy et al., 1) Cottid-fish Gadid-fish Flat-fish All fish All fish Flat-fish Gadid-fish Cottid-fish 1

22 Some long-term trends of demersal fish biomass at Sakhalin and Kuril Islands о. Сахалин average biomass per 1 sq. miles, ton South Kuril R² =,

23 Average relative biomass of dominant species of fishes at South Kuril, ton/sq. mile Eleginus gracilis Gadus macrocephalus Theragra chalcogramma P. monopterigius H.lagocephalus Pleurogrammus azonus Gymnocanthus detrisus Enophrys diceraus All cottid fish Myoxocephalus polyacanthocephalus Myoxocephalus jaok Pseudopleuronectes schrenki Cleisthenes herzensteini Glyptocephalus stelleri Lepidopsetta bilineata Myzopsetta herzensteini All flat fish 3

24 Dynamics of ice conditions, some atmospheric processes, and thermal regime of waters, intensity and direction of the main currents in the sea of Okhotsk in recent decades is in manifestly synchronous nature, allowing exploring the climate and oceanographic factors as a single integrated process, which has a decisive influence on the development of biological communities. Sakhalin Research Institute of Fisheries & Oceanography (SakhNIRO)