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Zooplankton of the Arctic Ocean: Patterns of Diversity and Productivity

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Zooplankton of the Arctic Ocean: Patterns of Diversity and Productivity Zooplankton of the Arctic Ocean: patterns of diversity and productivity Ksenia Kosobokova P.P. Shirshov Institute of Oceanology Russian Academy of Sciences, Moscow, Russia in collaboration with H-J. Hirche and R.R. Hopcroft The Arctic Mediterranean Sea Bering Strait = Arctic Ocean Arctic Shelf Water exchange with the North Pacific via Canada shallow (70m Canadian Basin deep) Bering Basin Strait Water exchange with the North Atlantic via deep (2000m) Fram Strait Fram Strait Strait Bering D e p t h, m Section through the Arctic Ocean Potential temperature (ºC) Chukchi shelf Canada Basin 0 ? Makarov ? 1000 ? Basin ? ? ? ? 2000 ? ) ? Amundsen ? ? ( ? Basin ? а ? н ? и 3000 б у л КанадскийNansenБассейн Г Макарова 4000 БассейнBasin Бассейн Бассейн Нансена Амундсена 5000 Температурный потенциал (°C) Strait Fram Water masses and circulation 0 Polar surface water: 0-200 m ф depth, negative temperature, ь 1000 л low salinity 30-34 psu е ш й и к ) 2000 с т м ( о к а у н Ч и 3000 б у л Канадский Бассейн Г Canada Makarov Depth (m) Depth 4000 БассейнBasin МакароваBasin БассейнNansen AmundsenБассейн НансенаBasin Амундсена 5000 PotentialТемпературный temperature потенциал ( °C) (ºC) Basin Atlantic water: 200-900 m depth, positive temperature, salinity 34-34.9 Arctic Bottom water: below 1000 m, negative temperature, higher salinity 34.93-34.99 First zooplankton collections were obtained during the “Fram” drift in 1893-1896 G.O. Sars, 1900. The Norwegian North Pole Expedition 1893- 1896. Scientific results. F. Nansen (ed.). V.1, No. 5. 141 pp. The first list of AO crustacean zooplankton with description of new species Russian drifting ice station ”North Pole” (NP1) 1937-1938 9 months of drift, zooplankton collected at 14 locations down to 1500m using a hand winch ColoredMost linesdrifting - routes ice stations of the started drifting their stations drift in NP the-2 – NP-Canadian37, 1950 Basin-1978,, where green the linestrongest - the and ice thickestisland T ice-3 platforms were chosen to build the ice camps, and they drifted mostly within this basin Canadian Basin Period of sporadic semi-quantitative sampling, For a long Different sampling methods and gears,time almost no data Different sampling layers (predominantlyexisted surface from layers 0-100, 0-500 m),the Eurasian Basin Difficult to drawEurasian any inter-regional and quantitativeBasin comparison… New Age since 1980-es: «Breaking the ice…» “Academician Fedorov”, Russia Icebreaker “Polarstern”, Germany USCGC “Healy”, USA Modern gears and standard sampling methods Multinet: Bongo net: ROV: Quantitative vertical sampling Oblique or In situ (5 to 9 layers) vertical sampling observations and collection of fragile organisms Scuba divers „Polarstern“ zooplankton sampling programs in the central Arctic, 1993-2015 Stations in 1993-1998, 2007, 2011 were located along sections crossing the core of the Atlantic Boundary current Siberia Siberia Greenland Greenland Zooplankton station locations, 1993- 2015 Stratified sampling of the water column with MN at 202 locations; 153 sts. at bottom depth >1000 m Expeditions: 1) RV “Polarstern”: ARK IX/4, 1993 ARK XI/1, 1995 ARK XII, 1996 ARK XIII, 1997 ARK XIV, 1998 ARK XXII/2, 2007 ARK XXVI/3, 2011 PS94, 2015 2) USCGC “Healy”, 2005 3) “North Pole” stations: NP-22: 1975-76 NP-23: 1976-77 Research objectives: • Study of the zooplankton diversity throughout the entire depth range to produce detailed inventory and to document any ongoing changes in the species composition; • Biomass and abundance assessment: how much and where? • Study of regional biomass variability: what factors shape it? • Polar zooplankton ecology: - study of life strategies and reproductive biology of epi- and mesopelagic zooplankton to better understand their life traits; - study of lipid contebt and starvation potential of lipid accumulating key copepod species; - organic carbon content analysis, C/N ratio, stable isotopes ratio, dry mass, and lipid composition in dominant plankton taxa Species composition and diversity Sub-project of the CoML ‘Arctic Ocean Diversity’ (ArcOD) program, 2007-2010 • Detailed inventory of the zooplankton fauna of the deep Arctic Ocean • Comparison of the zooplankton composition in the four major deep basins of the Arctic Ocean separated by underwater ridges (Nansen, Amundsen, Makarov, Canada basins) • Analysis of patterns of zooplankton diversity vs. water depth Kosobokova et al., 1998; Kosobokova & Hirche, 2000; Markhaseva & Kosobokova, 1998, 2001; Stepanjants & Kosobokova, 2006; Kosobokova & Hopcroft, 2010, Kosobokova et al., 2011; Andronov & Kosobokova, 2011; Zasko & Kosobokova 2014 Zooplankton diversity and taxonomical composition No. of Taxon A total of 175 species metazoan species • Arthropoda (Crustacea): 122 Copepoda 91 Ostracoda 5 Hyperiidea 6 Other taxa, Gammarideа 11 12% Mysidacea 4 Euphausiacea 4 Cnidaria 23 Decapoda 1 • Cnidaria: 25 15% 25 Scyphozoa (Scyphomedusae) 3 Hydrozoa (Hydromedusae) 15 Siphonophora 7 30 91 • Ctenophora 7 • Gastropoda (Pteropoda) 2 Other • Annelida (Polychaeta) 5 Crustacea • Nemertea 1 18% Copepoda, • Chordata (Larvacea) 4 54% • Chaetognatha 4 Kosobokova et al. 2011, Kosobokova 2012 Biogeography of AO zooplankton: 85% resident species (locally reproducing), and 15% expatriates (not reproducing) - High rank of endemism due to isolation of the Arctic Ocean deep basin; - Large portion of species shared with North Atlantic due to permanent advection of fauna with Atlantic water and similar conditions at depths; - Small portion of species shared with the Pacific Benthopelagic due to isolation by the shallow Bering Strait and wide shallow Chukchi Sea shelf Kosobokova 2012 Oceanic expatriates: Advection and distribution of Atlantic vs. Pacific species Legend 0 - 862 Neocalanus crystatus >862 - 3002 Pacific copepods Ncristatus Atlantic copepod Metridia pacifica >3002 - 5848 (ind m-2) Mpacifica Calanus finmarchicus Eucalanus bungei >5848 - 12348 Ebungii (ind m-2) >12348 - 41680 Vertical Vertical ranges Eurasian Basin Canadian Basin Abundance, ind m-3 s u l s s i a s s u n i h s c >1000.00 u r i n p u c s o r i g e i r e c s t l s o s e c i o a c u a c v v o 100 .01 - 1000.00 u n i n r i r r m n e i e o r c a g i r o c r g r t o a s p m n f increases with depth withincreases b a o y l n i n i s s s s a n l o i 10.01 - 100.00 b i i p g i s s a a s l s s maximum in Atlantic in Atlantic maximum g l u a i r l v u i u l s l u u u a a s s p m e n t e i c t n e u e n d n r o p o u u b e a a c t e r l m a b a 1.01 - 10.00 b n y l l i t n n o i a l l o o l r a a g h a s i a a s s a a s l h b n i l l h h e c c n Species number,s No.s c u a t u a d t a r a a i i a i i o o o 0.10 - 1.00 c u u u n c c o n r c r e e d Species diversity o e h h t r n n a o o i o e m o a a r t e a l p e p r a a r n n h c c t c e i l l r i i o a a t m i o < 0.10 e i n n a h a a a M c p c p c e and reaches its reaches and M P S S S H S S M 0 10 20 30O 40 50C 60C 70O 80 O G C T 0-25 Arctic0 25-50 Water 50-100 of m 200 , 100-200 h t 400Atlantic 200-300 p 300-500 e Water 600 500-750 D Arctic 750-1000 800 layer Bottom 1000-2000 species 1000Water 2000-3000 1200 -3 Abundance, ind m s s s s n s i u 1400 u e i l t i s e s i r r i c r r >1000.00 s e b s u a r s a e i t a o l s s g u a s s t a s r u p t a a i b o l u i o d u s n a s c a c r r t i k i a g r s p o i i l 1600 m n l t o b e s r e a 100 .01 - 1000.00 l a s a a i n p s r d l i o r r l s r o m a a l i p p a a g r f s p o o o a r i p c s a n o o s a r u i o r i y l s t c s l n t d c n b a p r i c d a s h e p s i s h m i l y a l o s t a 10.01 - 100.00 u . u v a l o l u s s u l e o a a s s s l b s l Depth,m c e u 1800 e p p u m r t t b d g o n u u o s n r u a u e u s u a g a e e n r o l s s b r a p p a b n n s n n n g n i i i a i a l a s a a g 1.01 - 10.00 t a l a a s l s a i a a u a a s u a h h h a a a u l l l l l l l l p i h s a i i i p p l k c i l u a c c i c e a a t t t r i a r a a a 2000 t c c o i o e t t o o o u b u c c n c c c o u u u g p o e e o d 0.10 - 1.00 p n y d e d e h r o o a o o o c c c i o a i u d d h b t r i i i o e r a a p u u i i c n n n l t g d a c e i b m m c c c t t a r r i i i s e e a i i a e i a e e u n n u h u s a s a u u u h 2200 < 0.10 p p p c A A A M M D E H S H L P S P P S P L L S L G C U T O 2400 0-25 2600Arctic 25-50 Water 50-100 m 2800 , 100-200Canada Basin, copepods h 3000t Atlantic 200-300Eurasian Basin, copepods p 300-500 e Water 500-750CB, all taxa D Arctic 750-1000EB, all taxa Bottom 1000-2000 Water 2000-3000 Deep-water residents: Lomonosov Ridge is not a barrier for the deep-water fauna Almost all deep-water species occur on both sides of the Lomonosov Ridge = There is an effective exchange of plankton fauna over the underwater ridges Quantitative composition: copepods dominate biomass 82ºN 86ºN Eurasian Basin 72-76ºN 86ºN Canadian Basin % of overall biomass Depth, m Eurasian Basin Canadian Basin Region Mean ± SD Mean ± SD Share of Continental slope 88.0 ± 11.4 74.4 ± 2.2 copepods Basins south of ± ± 82ºN 80.9 5.0 75.1 4.6 Basins north of ± ± 85ºN 91.4 2.8 93.4 5.4 Key copepod species Biomass (%) Body Eurasian Species length, Basin Eurasian Basin Canadian mm <82°N >85°N Basin Calanus glacialis 5.0 19.6 14.8 9.9 C.
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