Marine Ecosystem and Environment in the Tokyo Bay

–Past and Current-

Naho HORIMOTODepartment of Ocean Sciences

Faculty of Marie ScienceTokyo University of Marine Science and Technology

Clams digging to tidal flatHANEDA in 1930sA small fisheries village

HANEDA PresentA Famous conger fisheries Large Landfills - The Haneda airport and artificial islands -

Tokyo Bay is a pitiful sea. It has never been subjected for environmental conservation, so far.

Makoto Shimizu 　　　 Professor emeritus at the University of Tokyo

Tidal flat around　1900

136km2 10km2

1986

Tidal flatReclamation　―　1945　―　1975　―　1985Since　1986

Change of the Tokyo BayReclamation - Loss of organisms　and function of water purification in　tidal　flat-　

Japanese hard clam　（Meretrix lusoria）

Sandborer（Sillago 　japonica）

extinct species

Increased Population　around the Bay- Eutrophication -Changes in the population around Tokyo Bay and COD(Chemical Oxygen Demand) and nutrient load

Total nutrient load

Population:Tokyo Metro., Kanagawa, Chiba and Saitama Pref.

COD load

Total phosphate load

(t/d) (x1000)

Sta. F3 (35°30′N，139°49′E)Off Haneda Airport　Effect by the Tamagawa River　

Sta. F6 (35°25′N，139°47′E)Almost Center of Tokyo Bay

Sta. 06 (35°11′N，139°44′E)Bay Entrance (in the Uraga Channel)Front of Tokyo Bay and Coastal Water

Sta. 11 (35°02′N，139°39′E)Adjust area to Sagami BayEffected by Open Water

Surface Salinity on April 2004

(PSU)

Our Routine Observation in the Tokyo Bay

10km

TUMSAT

Seiyo Maru II< Undergraduate Education >・Freshman’s seminar “First SEA-GOING Cruise”・Training in Navigation and Fishing for the sea-training course（sophomore student for obtaining the certificate of the course ）・ Training in Oceanographic Observations (senior student)

< Oceanographic Research around Tokyo Bay and Sagami Bay >

Gross Tone 170t

Length 35.5m

Complement 14 Crews25 Student

丸 鷹 青SEIYO MARU

ADCPInlet Pump

AD convert

PC

・GPS・Water Temperature・Salinity・In vivo Chlorophyll Fluorescence

In the LAB

LAB

Underway Observation(every a minute data )

GPSMeteorological Observation 　→ on the compass deck・Wind speed and direction・Air Pressure・Air temperature

In the Bridge

GPS

Seawater

TS sensor

Fluorometer

ADCP(Acoustic Doppler Current Profiler)

Observation equipments #1

Sea Surface丸 鷹 青

SEIYO MARU

Sea Bottom

ORI Net

IONESS

Sledge NetDredge

CTD with Niskin Water

Sampler

Multiple Core Sampler

SecchiDisk

Van DornWater Sampler

NORPACNet

Larvae Net

Smith&McIntyreSampler

Observation equipments #2

Mooring operation and recoveryReal time measurement of Primary Productivity in Sagami Bay

(SORST - JST)Depth, Temperature, Salinity, In situ PAR,

Chlorophyll fluorescence, Primary Productivity by Fast Reputation Rate of Fluorescence

Underwater winch is designed that Buoy moves up and down with Kevlar rope in accordance with a time-table user programmed.Profiling Data is send to the Lab by email

CTD SYSTEM(Conductivity=salinity, Temperature and Depth)

Slip ring

CTD Cast Winch Control

Steel Wire Armored Cable

Deck Unit PC Operation

Water Sampling

Temperature

Conductivity(Salinity)

Dissolved Oxygen

Light Attenuation Coefficient(Turbidimeter)

Chlorophyll Fluorometer

light quantum(Irradiance)

Pressure(Depth)

Main Body

Cradle for Niskin Bottle

Sampler

CTD Sensors

CTD Vertical Profile in 20th December 2005 at Sagami Bay

Temperature(oC)

Salinity (Practical Salinity Unit)

Dissolved Oxygen (ml/l)

Turbidimeter (%)

In vivo Chlorophyll (ug/l)

light quantum (uE/m3/s)

Pres

sure

(Dep

th, m

)

Temperature

Dissolved Oxygen

Salinity

ChlorophyllTurbidimeter

light quantum

Routine Sampling in the Tokyo Bay (Sta.F3 and F6)

Sampling depths0, 5,10,15,20m

CTD-Niskin sampler

100ml

250ml

Nutrientmeasurementsautomated analysis

by Bran-Luebbe

Chl a analysisfiltered onto GF/F glass-fiber filters

extracted indimethyl formamide

(Suzuki and Ishimaru 1990)

determined by thefluorometoric method

NO2 ：Naphthyl-ethylenediamine MethodNO3 ： Naphthyl-ethylenediamine Method

(Reduction by Copper- Cadmium column)NH4 ：OPP Method (Kanda, 1995)PO4 ：Molybdenum Blue Color Comparison MethodSiO2 ：Molybdenum Blue Color Comparison Method

AACS III

Model 10

Spike with a NaH13CO3

Photosynthetic 13C incorporation

Incubate for 3-4 hours in an on-deck incubator

Only use a surface water

The irradiance simulated at the 100-1% relative light levels by use of various combinations of neutral-density filters

filtered onto precombusted GF/F glass-fiber filters

Measured by Infrared absorption spectrometry （JASCO, EX130S）

calculated primary productivity （Hama et al. 1983）

F6F3

35˚ 40’

139˚ 40’ 140˚ 00’35˚ 10’

35˚ 20’

35˚ 30’

100　50　 25　12.5　6　 3 　1%

250ml

Non-phosphatedetergent

Improvement in sewerage treatment

NH₄‐N

NO₃‐N

PO₄‐P

After In Tokyo Bay –Its Environmental Changes (in Japanese)

Changes in surface nutrient concentrations

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1990 1991 1992 1993 1994 1995 1996 1997 19981989

2530354045505560657075

10

20

30

40

50

DIN

(µM

)Si

(OH

) 4-S

i (µM

)PO

4-P

(µM

)F3F6

Cocks-Start TestTrends of decrease

(a=0.05)

Result from Mastumura et al. (2001)

Changes in surface nutrient concentrations at Sta.F3 and F6

After Kawabe and Kawabe (1997)(Chemical Oxygen Demand)

Variation of surface COD and DIN, and solar radiation

10

20

30

40

253035404550556065707511

11

12

12

13

13

14

1989 19911990 1993 1994 1995 1996 1997 19981992

Result from Mastumura et al. (2001)F3F6

F3F6

Chl

a(µ

g/l)

Sola

r rad

iatio

n (M

J/m

2 )D

IN (µ

M)

Variation of Chl a, solar radiation, and DIN at Sta. F3 and F6

0

2

4

6

8

10

12

14

16

1 2 3 4 5 6 7 8 9 10 11 12

1963年

1972年

1988年

2000以降平均

gC m-2 day-1

-2005 Average

J F M A M J J A S O N D

Ichimura, 1967Yamaguchi & Ichimura, 1976Yamaguchi et al., 1991

Seasonal variation and transition of Primary Production and Chl a at Sta. F3

0

100

200

300

4001963年

1972年

1988年

2000以降平均

mg Chl a m-2

μM

0

10

20

30

40

50

60

70

80

63 72 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04

0

1

2

3

4

5

6表層DIN濃度 (uM)

表層Chl a 濃度(ug L-1)

生産力 (gC m-2 day-1)

～ ～

μg L-1 gC m-2 day-1

surface DIN

surface Chl a Production

Transition of surface DIN and Chl a, water column production at Sta. F3

Red Tide (a decade AV)

Blue Tide (a decade AV)

Red TideBlue Tide

1950-1970s 1980-1990s

Occ

urre

nce

Tim

es

Ceratium

Gonyaulax

Skeletonema

Chaetoceros

Prorocentrum

Heterosigma

Before 1950s

Occurrences of red tide and blue tide

P N

Red Tide and Blue Tidegreatly increased amounts of phosphorus or nitrogen entering an aquatic ecosystem from either sewage systems or agricultural fertilizers

Phytoplankton are microscopic, single-celled plants.Phytoplankton is a primary producer in the ocean.

Bottom anoxia and extinction of benthos

Red tide andEnd of bloom, phytoplankton accumulate on the sea bottom and microbes consume large amount of oxygen to decompose them.

Southern wind cause upwelling

Sulfur was educed due to oxidation of hydrogen sulfide, that color is light blue and tint smells of sulfur

Change in the major copepod species at Sta.F6 (Nomura, 1993)

References

Observed yearMethod of a

sampling (times)NET/

WATER

References

Observed yearMethod of a

sampling (times)NET/

WATER

Suda et al

Kurashige

Tokyo Metro.Fish. Fujitani

Yamazi Marumo&Murano

Marumo&Murano

Anakubo&Murano Nomura

●:Dominated，○：Appeared

Oithona davisae

Acartia omorii

Oithona similis

Microsetella norvegica

Polluted condition have never been changed.Organic load from land decreasedOnly slight decrease in nutrient load Organic matter is produced in the bay causing pollution

Environmental monitoring have intensively conducted, but no counter measure

What should we do now?

Summary　Environment of Tokyo Bay have been deteriorated by 　reclamation and population increase　Extinction of animals in tidal flat　Eutrophication with population increase 　 Red tide, blue tide and bottom anoxia

Low diversity

Dissolved organic carbon

Trophic transfer of carbon

Classic food chainMicrobial loop

PICO MICRONANO0.2µm 2µm 20µm 200µm MACROsize

Diagram of a marine food chain

0.1Chl a

(µg L-1)0.5 1 10Composite image of chlorophyll

concentration in the ocean(source SEAWIFS project)

Annual mean nitrate at the surface (source World Ocean Atlas @ NODC)

<1 10 20 >30(µM)

nutrients

Small

Open Ocean

Large

Coastal + Upwelling area

Chl aHL

How does phytoplankton biomass and species composition vary ?What size dominates within each area?