Human Activities in Northeastern Asia and their Impact to the

Biological Productivity in North Pacific Ocean

S. NAGAO, T. SHIRAIWA, T. NAKATSUKA

1Faculty of Environ. Earth Sci., Hokkaido University2Res. Inst. Humanity and Nature

3Inst. Low Temp. Sci., Hokkaido University

2006.5.16-17Beijing, China

Outline of this presentation

1. Background and objectives of the Project“Amur-Okhotsk Project”

2. Migration behavior of Fe in Amur Rivera. Analyses of pre-existing data-sets

b. Preliminary results

3. Summary

Chl-a concentration at surface (June)

Nitrate concentration at surface (Summer)

Northern North Pacific and its marginal seas are known as areas of the highest productivity in the world

<Reason> 1. Goal of deep water circulation2. Winter convection

= nutrients supply from deep water in winter

However, there remain nutrients unutilizedat surface even in summer at the center of its area (=HNLC), because of

Shortage of dissolved Fe

The Sea of Okhotsk is not “HNLC”.Complete utilization of nutrients

→ Higher productivity.

Possibly due to input of Fefrom Northeastern Asia

(via Amur River & Atmosphere)

1. Background of the Project

Fe transport

Atmospheric Fe transport

Estuary

Processes

Primary Production

Production of dissolved iron

Amur River basin Sea of Okhotsk& Northern

North Pacific

Proposal for sustainableLand-uses to maintainThe Marine Ecosystem

Fe Discharge model

Biomass production model

Political, Economic, and

Sociological BackgroundLand-Use Changes

Rapid degradation of land surface

Discharge

Objectives of the Project

Watershed area 1.89x106km2

Length 4440km

Upper and middle AmurForest

Lower AmurWetland & Forest

Marine Group Land-use Group

Amur-Okhotsk Project

FEHRI (Russia)

IWEP (Russia)HYDROMET (Russia)

Nankai Univ. (China)Northeast Forestry Univ. (China)NIGAE (China)IAE (China)

PIG (Russia)

NIGAE (China)

Structure of the Project

GISLand & River

Processes Group

表面流出 沿岸海洋での動態河川移行

Amur RiverSanjiang Plain

Usuri RiverSonghua River

Amur-Liman

Dissolved FeMixing zone

Okhotsk SeaOyashio reagion

High primaryproductionTransportation

Aggregation redissolution

Input from forest areaand groundwater

2. Migration behavior of Fe in Amur River system

Where, When, HowImportant information on geochemistry of Fe

Nikolaevsk

Komsomorisk

Khabarovsk

Blagoveschensk

Okhotsk Sea

Japa

n Se

aS

akha

lin

Song-Hua Jian

China

Russia●

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Fe (mg/l: annual average)

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1.5 mg/l

1.0 mg/l

0.5 mg/l

0.1 mg/l

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Analyses of existing data set in 2002

38 Hydromet stations

Spatial distribution of Fe concentration

Khabarovsk

Komsomorisk-na-Amure

Nikolaevsk-na-Amure

Blagoveschensk

Cherniaevo

Amursk

Khabarovsk 2002

0

5000

1 104

1.5 104

J F M A M J J A S O N DW

ater

Dis

char

ge (m

3 /sec

)Month

(March-Dec. in 2002)

Seasonal variation in Fe concentration

0

0.2

0.4

0.6

0.8

1

1.2

Fe (m

g/l)

Sampling date

Khbarovsk

Blagoveschensk

Cherniaevo

MAM JJ A S O N D0

0.2

0.4

0.6

0.8

1

1.2

Fe (m

g/l)

Sampling date

Amursk

Nikolaevsk

Komsomolsk

MAM JJ A S O N D

Wetland River

Fe3+ → Fe2+ （In anoxic condition,Fe3+ is reduced to Fe2+, dissolved into groundwater and finallydischarged to river.

Fe2+ → Fe3+Movement of groundwater

Supply of humicsubstances such as fulvic acid intoriver

Formation of complex(fulvic acid＋Fe3+)→can be dissolved

Fe2+ is easilyoxidized andsinks down

quickly againin river…

Conditions to dissolve iron (Fe) into river (Amur)In oxic environment, iron is Fe3+. It cannot be dissolved in water.

(1) “Water” – environment such as Wetland

(2) “Forest” – supply of humic substances

Group 3: Fe flux Monitoringin River & Estuary

1. Seasonal & inter-annual variations in Fe flux

2. Distribution of Fe source and sink 3. Fe dynamics in the estuary

Periodic water samplings & analyses at fixed stations

Research cruises using a research vessel for river

Investigation of river moutharea using a small marine vessel

Group 4: Monitoring of Fe Flux from Various Types of Land Surfaces to River

1. Natural forest vs burned forest2. Wetland vs Farmland

→Fundamentals for estimate of total Fe flux from the whole Amur River Basin.

Sampling at terrestrial environment

研究項目２

Hkabarovsk

Bogorodtskoe

Komsomorisk-na-Amure

Amur River observation

Amur and its tributaries observation

Wetland observation

Nikolaevsk-na-Amure

Gur River

Anvi River

Amgun River

Gorin River Sofiisk

Lidoga

Takhta

Niznetambovskoe

Troitskoe

Research Activities in 2005

R/V Ladga

0

0.5

1

1.5

2

2.5S

t.1

St.A St.2

St.3

-1

St.3

-2

St.4

St.5

-1

St.5

-2

St.5

St.6

St.7

-1

St.7

-2

St.8

St.9

St.L

St.G

Fe (m

g/l)

Site

River cruise studies -Lower Amur River-August 2005

(Makhinov, unpublished data)

Upland field

Wetland

Paddy field

Spatial distribution of Fe conc. in Sanjiang Plain

August in 2005

0

0.5

1

1.5

2

2.5

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4

St.A

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6

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7

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12

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14

St.A

16

St.A

21

St.A

22

St.A

29

St.A

30

St.A

31

Fe (m

g/l)

Site

(Zhang, unpublished data)

表面流出 沿岸海洋での動態河川移行

Sanjiang Plain

Usuri RiverSonghua River

Amur-Liman

Mixing zone

0

2

4

6

8

10

12

0 10 20 30 40 50

Fe (m

g/l)

DOC (mg/l)

River

Groundwater

Drainage

Amur River

0

0.5

1

1.5

2

2.5

0 5 10 15

Fe (m

g/l)

DOC (mg/l)

River

Dissolved Fe and DOC concentrationin Amur River system

Positive correlation between Fe and DOC concentrations

August2005

KhabarovskNikolaevsk-na-Amure

(RHIN, unpublished data)

0.64±0.07mg/l0.30±0.03mg/l

Dissolved forms of Fe in river watersImportant information on transportation

bioavailability

Amur River system

Possible Fe-organic complexes(humic-like materials)

Effects of human activities・land-use change(wetland ⇨paddy field)・logging activites・forest fire

RUSSIA

CHINA Amur River

Song hua jiang

Ussuri River

Sea of Okhotsk

East Sakhalin Current

Cruise by Russian Research Vessel(2006 & 2007)

1

2

3

Group 2: Chemical & Biological Oceanography

1. Fe dynamics on the shelf sediment2. Distribution and source of Fe (river

or atmosphere), Fe impact to phytoplankton production

3. Fe flux from Okhotsk to Pacific

Evaluation on Fe impact to phytoplankton production

Sampling at marine environment

Summary

“Amur-Okhotsk Project”

Migration behavior of Fe in the Amur River system

・Source of FeLower Amur River & around Khabarovsk

wetland, groundwater・Maximum of Fe concentration and flux

July-Augustrelation with increase in water level

・Dissolved forms of FeFe-organic complexes and Fe-organic colloids

(organic matter:humic substances)

Acknowledgments・China

Nankai Univ.------------Dr. F. ShiNortheast Institute of Geography and Agricultural Ecology

------------Dr. B. Zhang

・RussiaIWEP----------------------Drs. B. A. Voronov, A. N. MakhinovHYDROMET-------------Dr. A. Gavrilov

・JapanHokkaido Univ.---------Drs. H. Shibata, O. SekiTokyo Agriculture and Technology--Dr. M. YohKyoto Prefectural Univ.----Dr. H. KodamaRIHN----------------------Dr. M. Terashima

Thank you for your attention!

(Photo Amur River: Amur River cruise 2005.8.16-8.24)

Observation points at research cruise in 2005

St.1

St.NSt.9

St.10

St.8

St.2St.A

St.M

St.J’

St.4

St.3

St.5St.6

St.7

St.E

St.B

River bankRiver bank

Wetland

Wetland

Preliminary results in the river cruise

0

50

100

150

200

St.A St.3 St.4 St.5 St.7 St.J' St.10 St.N

Turb

idity

(mg/

l)

Station

5

10

15

St.A St.3 St.4 St.5 St.7 St.J' St.10 St.N

Con

duct

ivity

(mS

/m)

StationSt.1

St.NSt.9

St.10

St.8

St.2St.A

St.M

St.J’

St.4

St.3

St.5St.6

St.7

St.E

St.B

Concept of humic substances ・Colored, polyelectrolytic organic acids

・Nonvolatile and range in molecular weight from 500 to 5000

・Elemental composition 50% C, 4-5% H, 35-40% O, 1-2% N

・Major functional groupscarboxylic acids, phenolic hydroxyl

・Two fractionsHumic acid: precipitates at pH2 or lessFulvic acid: remains in solution at pH2 or less

Molecular weight of humic substances

Humic substances have a wide range ofmolecular weight ranging from a few

hundred to several hundred thousand.

polyelectrolytic organic acids

Sample DOC(mg/l) %HS/DOC %FA/HS Reference

Kuji FA 2.9 12 95 This work

Deer Creek FA 3.6 75 89 McKnight et al.(1992)Snak River FA 1.8 42 86

Omoshironbetsu 3.0 29 --- Nagahora et al.(2002)River FA 5.4 28 ---

Amazon River ItePeua 3.6 37 80 Ertel et al.(1986)Rio Negro 10.8 54 60Obidos 4.5 35 77

The amount of humic substances in river waters

Complexation ability of humic substances

Model structure of humic acid

Fe2+,Fe3+

The ability of humic and fulvic acids to form stable complexes with metal ions can be attributed to their high content of O-containing functional groups, including COOH, phenolic-OH.

Humic acid Fulvic acid

Sahan River water

1 0- 6

1 0- 5

1 0- 4

1 0- 3

1 0- 2

0 10 20 30

Pu-239+240

Am-241

Cm-244

DOC concentration (mg/l)Rad

ioac

tive

conc

entra

tion

(Bq/

l)

Relationship between the concentrations of radioisotpes and DOC

(Matsunaga and Nagao, 2001)

HS 80-90% of DOC

Raw river water

Purification

HS adsorbed on DEAE-cellulose resin

Sahan river water

Humic substances play an important role in geochemical behavior of trace elements in aquatic environments

Role of organic materials(1) -Transport-

0

2

4

6

8

10

0 20 40 60 80 100

Fe (m

g/l)

DOC (mg/l)

r=0.87

Wetland

Wetland

Wetland is a major source of Fe-humate complexes in terrestrial environments

Peat solution

(Tani et al., 2001)

50-80% of DOC is occupied by humic substances

Wetland in Hokkaido

Role of organic materials(2) -Source-

Monitoring of aquatic humic substances Three-dimensional fluorescence spectroscopy

Clarify concentration and characteristics of humic substances by a simple and convenient method

300 350 400 450 500 550 600

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450

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Emission/ nm300 350 400 450 500 550 600

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450

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300

250

Emission/ nm

(a)SuwanneeHA

(b)SuwanneeFA

Exc

itatio

n/ n

m

Exc

itatio

n/ n

m

peak

Example of humic and fulvic acids isolated from river waters

Fluorescence peak position

Fluorescence peak position varies with samples with different environmental conditions

3-D EEM spectra of river waters

Sahan RiverYodo River Kuji River

WetlandsBrown forest soil

淀川河川水 久慈川河川水 サハン川河川水

250 350 450 550

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450

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Urban area

Exc

itatio

n/ n

m

Emission/ nmEmission/ nm Emission/ nm

Exc

itatio

n/ n

m

Exc

itatio

n/ n

m

200

350

500

250 400 550Emission (nm)

Exci

tati

on (

nm

)

10 mg/l 別寒辺牛川FASt.3 (2003.11.27)

250 400 550Emission (nm)

250 400 550Emission (nm)

250 400 550Emission (nm)

250 400 550Emission (nm)

(2005.2.15)

200

350

500

Exci

tati

on (

nm

)

contour = 5 QSU

(2005.4.14)

(2005.8.2)2倍希釈 (2005.12.1)

Isolated FA River water

Three-dimensional excitation emission matrix spectra of Bekanbeushi River waters

St.1

St.2

St.3

St.4

St.6

St.5

トライベツ川

別寒辺牛川

大別川

尾幌川チライカリベツ川

Fe c

onc.

(mg/

l)

Fe c

onc.

(mg/

l)Fe

con

c. (m

g/l)

Fe c

onc.

(mg/

l)

Fe c

onc.

(mg/

l)

Relation between Fe conc. AndRFI of fulvic acids

0

0.2

0.4

0.6

0.8

0 50 100 150RFI at Ex320/Em.430

0

0.2

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0 50 100 150RFI at Ex320/Em.430

2005

0

0.2

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0.8

0 50 100 150RFI at Ex320/Em.430

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0.8

0 50 100 150RFI at Ex320/Em.430

0

0.2

0.4

0.6

0.8

0 50 100 150RFI at Ex320/Em.430

Spring

r=0.97

Spring

r=0.93

r=0.98

r=0.90

r=0.90