Recent 1000 years variability. Aquatic microbiology and biogeochemistry Polar element cycling: A case study from Young Sound

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1 Aquatic microbiology ad biogeochemistry 2006 Polar elemet cyclig: A case study from Youg Soud Roie N Glud, Marie Biological Laboratory Recet 1000 years variability 1

2 Idicators of the Huma Ifluece o the Atmosphere Simulated aual global mea surface temperatures Source : IPCC 2

3 Treds i mea aual surface air temperature i C per decade orth of 40 N for the period (Source Serreze et al. 2000) Short-term variability Short term temperature variatios i Youg Soud (NE Greelad) (1m above groud) 3

4 Icrease ad decrease i the legth of the sea ice seaso (Source: Parkiso et al 2000, 2002) I the period Overall decrease i sea ice distributio: ± 3700 km 2 /year (-2.8 %/decade) Youg Soud a typical Arctic estuary Total area 390 km 2 Volume 40 km 3 Average depth 100m 45-m sill Rysgaard et al Arctic, Atarctic ad Alpie Research 35:

5 Coditios i Youg Soud 180 Ice free period (days) year Sow & ice cover 5

6 Catchmet area 3109 km 2 Youg Soud receives 1063 mill. m 3 of freshwater from catchmet area ad 440 mill m 3 from sea ice Rysgaard et al Arctic, Atarctic ad Alpie Research 35: Hydrography Rysgaard et al Arctic, Atarctic ad Alpie Research 35:

7 Import export of DOC (ad utriets) Rysgaard et al Arctic, Atarctic ad Alpie Research 35: Seasoal ice-cover 24. Okt 1. Mar 1. Jue 7. July Glud et al. (submitted) 8. July 7

8 Sea-ice algae patchiess 20 Depth (cm) Light (%) Sow Sea ice 150 Dowwellig Irradiace (mmol photos m -2 s -1 ) Jue 16 Jue 21 Jue 26 Jue 1 Juli Time 200 Water Primary productio (µg C/l/d) Distace from hole (m) Depth below sea ice (m) Glud et al submit 1998-data primary productio (sea-ice algae) Sea ice algae Rysgaard et al. (2001) Mar Ecol Prog Ser 223:

9 primary productio (sea-ice algae) Biomass 3 mg Chl a m 2 PP 2.7 T C Rysgaard et al. (2001) Mar Ecol Prog Ser 223:15-26 Glud et al. i press Freshwater- dyamics at the sea-ice water iterface: prevetig sea-ice algae domiace? Three photos of the sea-ice water iterface i Youg Soud obatied withi a 2 week period Rysgaard et al. (2001) Mar Ecol Prog Ser 223:

10 Sea- Ice a complex matrix freezig opoit (oc) Saliity Lab-study o gas dyamics i sea-ice Oxyge microprofiles Glud et al. (2002) Aqua Microb Ecol 27:

11 Oxyge freezes out of sea-ice -8 o C Isulatio Developig sea-ice Seawater Glud et al. (2002) Aqua Microb Ecol 27: Most O 2 i sea-ice is eclosed i bubbles Rysgaard & Glud (2004) Limol Oceaogr 49:

12 Net-heterotrophic sea-ice Rysgaard & Glud (2004) Limol Oceaogr 49:86-94 Aoxic processes ca occur i sea-ice Deitrificatio (CH 2 O) 106 (NH 3 ) 16 H 3 PO NO H + 106CO NH NO N H 2 O + H 3 PO 4 Aammox 16NH NO N H 2 O Deitrifyig bacteria amout to 2 x 10 6 cells ml -1 brie Rysgaard & Glud (2004) Limol Oceaogr 49:

13 Coclusio o sea-ice experimets: Sea ice O 2 coditios are highly dyamic compromisig biological iterpretatio (gasses freeze out of sea-ice -> effects?) DOC, NO 3- ad NH 4+ are preset Capacity for deitrificatio & aammox (15-30% of bethic activity ) If sea ice disappears N-removal (ad C budgets) will be affected Sea-ice microalgae of o importace for C-cylig i YS Other gases? ice-cover disapperece iitiates a pelagic bloom 1. Jue 7. July 8. July Rysgaard et al. (1999) Mar Ecol Prog Ser 179:

14 Bethic primary productio Bethic diatoms & corallies 30 m depth Glud et al. (2002a) Mar Ecol Prog Ser 238:15-29 Roberts et al. (2002) J Phycol 38: Light adaptatio of bethic primary productio Glud et al. (2002a) Mar Ecol Prog Ser 238:

15 Bethic primary productio Macrophytes Borum et al. (2002). Mar Biol 141: Relative cotributio to primary productio i Youg Soud (sectio 1+2) Youg Soud > 30m corallies macrophytes microphytes Youg Soud total microphytes corallies phytoplakto macrophytes phytoplakto ice algae ice algae Glud et al. (2002a) Mar Ecol Prog Ser 238:15-29 Rysgaard & Glud. book i preparatio 15

16 Grazig ad primary productio Sea-ice cover Grazig estimates close to 100% of PP Rysgaard et al. (1999) Mar Ecol Prog Ser 179:13-25 Madse et al 2001 Biomass (g C m -2 ) Biomass (g C m -2 ) Copepods (C. hyperboreus, C. glacialis) Protozooplakto 0 A M J J A S O N D J F M Ice cover i Yog Soud Levise et al 2000a Icreasig ope water => 1) Ealier sprig bloom 2) Icreased productio 3) Ascedig copedops 4) Protezoa more importat 5) Less trophic trasfer 6) Pelagic bethic couplig 16

17 Sedimetatio data 40% of POC from lad C/N ratio summer 22 C/N ratio witer 7-9 Sedimetatio Carbo 60 m mmol C/m 2/d Aual sedimetatio = 1593 mmol C/m jul 1-sep 21-okt 10-dec 29-ja 20-mar 9-maj 28-ju 17-aug 6-okt Sea ice, cm Rysgaard et et al. (upublished) Pelagic-bethic couplig (Seasoality) 17

18 Sedimetatio effects o bethic mieralizatio Rysgaard et al (1998) Mar Ecol Prog Ser 175: Thamdrup, Glud ad Hase (submitted) Bethic activity atteuates with depth DIC Oxyge Glud et al (2000) Mar Ecol Prog Ser 206:59-71 Thamdrup, Glud ad Hase (submitted) 18

19 Pathways of the bethic mieralizatio (mmol C/m 2 /yr) Depth (cm) Thamdrup, Glud ad Hase (submitted) Rysgaard et al. (1998) Mar Ecol Prog Ser 175: Bethic microbial mieralizatio versus Burrial Thamdrup, Glud ad Hase (submitted) 19

20 Carbo preservatio i Arctic (Thamdrup et al i press) Cafield 1993, (Glud et al 1998, 2000, (Thamdrup et al i press) Sedimet mieralizatio at sub-zero temp do ot qualitatively or quatitatively differ from temperate or tropical sedimets but due to ormal Q 10 respose the pelagic-bethic couplig appears to be looser 20

21 Profile modellig ad dyamis of carbo turover i a Arctic sedimet C C ( ξϕ + ρ s ( 1 ϕ ) K ') = ( ξϕ ( D Bw + D s ) + ρ s ( 1 ϕ ) D Bs K ') t x x (( ξ ( ϕ u ) x + ρ s (( 1 ϕ ) w ) x K ') C ) + ξϕα ( C 0 C ) R + x Berg et al. (2003) Am J Sci 303: Profile modellig ad carbo turover dyamics i a Arctic sedimet Sedimet depth (cm) Nitrate Ammoium Oxyge Oxyge Nitrate Ammoium Berg et al. (2003) Am J Sci 303:

22 A example of pertubatio effects - icreased orgaic loadig Berg et al. (2003) Am J Sci 303: Bethic faua distributio Sejr et al. (upub) 22

23 Bethic faua distributio Sejr et al. (upub) Sejr & Christese (submitted) Quatitative importace of faua versus microbial mediated O 2 uptake Aarhus Bay (DK) (temperate) Youg Soud Macrofuaa resp (17%). (Macrofuaa resp. 24%) 1D diffusio irrgatio 3D diffusio 1D diffusio + 3D diffusio + irrigatio Glud et al Limol & Oceaogr 48: Rysgaard & Glud Book i progress Sejr et al i progress 23

24 Bivalves at the sea floor Shell legth (mm) N = 117 R 2 = age (yr) Max Chl a i Yog Soud Sejr et al. (2002) Mar Ecol Prog Ser 244: Walrus a summer visitor Bor et al. (2003) Polar Biol 26:

25 I 74 h (412 dives) a walrus cosumes 7000 mussels per day correspodig to 78 kg soft tissue bivalve per day 6.7% of its body weight (Bethic microalgae distributio) Bor et al. (2003) Polar Biol 26: Carbo budget g C/m 2 /yr 0-40 m m The fjor is et-heterorophic Prelimiary data from Rysgaard & Glud book i progress 25

26 Temperature ad precipitatio coditios i relative to Temperature o C Precipitatio mmd -1 Rysgaard et al Arctic, Atarctic ad Alpie Research 35: Predicted chages i ice coditios of Youg Soud Rysgaard et al Arctic, Atarctic ad Alpie Research 35:

27 Light coditios today ad i future? Borum et al Mar Biol 141:11-19 (ca. 60% icrease i light) Expected chages i pelagic primary productio as a fuctio of the ice-free period Rysgaard et al. (1999) Mar Ecol Prog Ser 179:

28 Effects of icreased freshwater iput to Youg Soud? Rysgaard et al Arctic, Atarctic ad Alpie Research 35: Pragmatic approach - use existig climate gradiets. Rysgaard et al Arctic, Atarctic ad Alpie Research 35:

29 Rysgaard & Glud (eds): Artic Carbo cyclig a case study from YS (14 Chapters) Thaks to >35 collaborators participatig i > 20 expeditios durig the last 12 years More iformatio available o the iteret Nyt stort kulstof-kredsløbs projekt omkrig fiskebakere udfor Nuuk Speciale-projekter i Mieraliserig, betisk PP, betisk faua, Betisk microbiologi mv 29