jiaozhou bay (china-yu)dip 0030.03 mg l-1 (0970.97μm) nsqs cl iiclass ii din/dip ratio 16 redfield...

Expert meeting on Marine Expert meeting on Marine Eutrophication Eutrophication in the in the

E t hi ti A t E t hi ti A t

p gp g ppNorthwest Pacific RegionNorthwest Pacific Region

Eutrophication Assessment on Eutrophication Assessment on JiaozhouJiaozhou Bay in Bay in ChinaChina

ZhimingZhiming YU & YU & ZaixingZaixing WUWU

Institute Institute of of OceanologyOceanologyChinese Chinese Academy of Sciences Academy of Sciences

55 AugAug., 2013·Toyama., 2013·Toyama, Japan, Japan1

1.1. Scope of Assessment and Scope of Assessment and C ll ti f D tC ll ti f D tCollection of DataCollection of Data

2.2. Data processingData processingp gp g

3.3. Setting of assessment criteriaSetting of assessment criteria

4.4. Assessment process and resultsAssessment process and results

55 Assessment summaryAssessment summary5.5. Assessment summaryAssessment summary

6.6. Conclusions and suggestionsConclusions and suggestions

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3

1.1 Selection of assessment 1.1 Selection of assessment areaarea

Jiaozhou Bay is located in Qingdao, which is a semi-enclosed b d dj t t th N th Y ll Sbay and adjacent to the North Yellow Sea.

It is about 390 km2 area and average 7 m depth, an important water body for port, aquaculture and tourism.

North China

Bohai Sea

North China

lBeijing

Shandong Peninsula

Hebei

Jiaozhou Bay

North Yellow Sea

Jiangsu

120 0 12060 Km

4

It is characterized by temperate waters: ice-free for all-year round, a y p y ,temperature range of 2℃ (lowest) in winter to 28℃ (highest) in summer.

Salinity is around 32 psu. A few rivers around the bay and average input 9 3is about 2×109m3/a. Water exchange time is about 50 days.

Especially, Qingdao is developed around Jiaozhou bay and the effect of human activity is very evidenthuman activity is very evident.

ChengyangDagu River

Moshui RiverMain pollutants are DIN and DIP, e.g. 7800t of DIN and 270t of DIP were

Jiaozhou Bay

JiaozhouLicun River

Haipo River

Licun7800t of DIN and 270t of DIP were discharged into Jiaozhou Bay in 2001.

There were some red tide eventsQingdao

l

Haipo RiverThere were some red tide events recorded in the past ten years.

So, Jiaozhou bay is a typical water body of north yellow sea in China for coastal eutrophication

Huangdao

Shandong Peninsula

Bohai Sea

North Yellow Sea

North China l

China for coastal eutrophication assessment.

120 0 12060 Km

North Yellow Sea

5

1.2 Division 1.2 Division of assessment of assessment areaarea

According to water exchange capability in different areas of th b th t di id d i t i ( bthe bay, the assessment areas were divided into inner (sub-area A), mouth (Sub-area B) and outside (Sub-area C).

ChengyangDagu River

Moshui River

Jiaozhou Bay

JiaozhouLicun River

Licun

QingdaoHaipo River

A

BC

Huangdao

Shandong Peninsula

Bohai Sea

North China lB

North Yellow Sea

120 0 12060 Km

North Yellow Sea

6

1.3 1.3 Collection of relevant information Collection of relevant information

Assessment data were mainly collected from following sources:

Jiaozhou Bay Marine Ecosystem Research Station

13 year’s monitoring data, 4 seasonal cruses (Feb, May, Aug and Nov) per year at 12 sampling stations

Bulletin of Marine Environmental Q lit f Qi d

Aug and Nov) per year at 12 sampling stations.

Quality of Qingdao

Bulletin of Marine Environmental Quality of Shandong Province JZB03JZB02

Jiaozhou BayJiaozhou

ChengyangDagu River

Moshui River

Licun

Quality of Shandong Province

Bulletin of Marine Environmental Quality of China

#

# #

# # #

#

#JZB13

JZB09

JZB07

JZB06JZB05JZB04

JZB03JZB02

JZB01

Qingdao

Licun River

Haipo River

y

Bulletin of Marine Disaster of China

#

###

JZB12 JZB10

JZB09

JZB08

Huangdao

Shandong Peninsula

Bohai Sea

North China l

Published monograph and papers North Yellow Sea

120 0 12060 Km

North Yellow Sea

7

1.4 1.4 Selection of assessment parameters Selection of assessment parameters Category Parameters recommended Parameter in this report Reason

Riverine input (TN, TP) Riverine input of DIN, DIP No TN, TP data

Total nitrogen/Total phosphorusI:Degree of

nutrient enrichment

Total nitrogen/Total phosphorus (TN, TP) √

Winter DIN, DIP concentration Annual average DIN, DIP DIN and DIP in winter are underrepresented.Wi t N/P ti (DIN/DIP) A l DIN/DIP ti are underrepresented. Winter N/P ratio (DIN/DIP) Annual average DIN/DIP ratio

II:Direct effects

mean of Chlorophyll a concentration (field data) √

Maximum of Chlorophyll a (field √II:Direct effects of nutrient enrichment

Maximum of Chlorophyll a (field data) √

red tide events (diatom species) √

red tide events (flagellate species) √red tide events (flagellate species) √

III: Indirect effects of nutrient

Bottom Dissolved oxygen (DO) √

Fish kill incidents √

√enrichment Chemical oxygen demand (COD) √

IV: Other possible effects Red-tide events (Noctiluca sp.)

√Mesodinium sp. also was

Frequently observed in the bay, also reflecting possible effects

of nutrient enrichment

considered eutrophication effects

Shellfish poisoning incidents √8

1.5 Final 1.5 Final assessment parameters assessment parameters

Category Assessment parameter Timescale of parameters

Riverine input of DIN 1980s.1999, 2001, 2005, 2008

Category I (degree of nutrient

enrichment)

p , , ,

Riverine input of DIP 2001,2005,2008

Annual mean TN、TP concentration 1997-2009

A l DIN DIP t ti 1997 2009e c e t) Annual mean DIN、DIP concentration 1997-2009

Annual mean DIN/DIP ratio 1997-2009

Annual maximum of Chlorophyll a 1997-2009

Category II (Direct effects) Annual mean of Chlorophyll a 1997-2009

Red tide events (diatom species) 1997-2009

R d tid t (fl ll t i ) 1997 2009Red tide events (flagellate species) 1997-2009

Category III (Indirect effects)Bottom annual mean DO 2001-2006

Annual mean COD 1997-2009

Fish kill incidents 1997-2009

Category IV (other effects)

Red-tide events (Noctiluca sp. and

Mesodinium sp )1997-2009

Category IV (other effects) Mesodinium sp.)

Shell fish poisoning incidents 1997-2009

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All data was processed according to NOWPAP common All data was processed according to NOWPAP common procedure revised in 2013.procedure revised in 2013.

DIN concentration was the summation of ammonia, nitrite and 4+ 2 3nitrate (NH4+, NO2- and NO3-).

The annual values and maximum in the assessment were respectively the average and maximum of four seasonal cruses inrespectively the average and maximum of four seasonal cruses in the year.

Comparison and occurrence were identified based on the data in precent 3 years.

Trend was identified by non-parametric Mann-Kendall test. If the data was not enough (>13), the linear regression was used for trend analysis.

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3.1 Setting of identification criteria of the assessment 3.1 Setting of identification criteria of the assessment datadata

Category Assessment parameter Units Assessment value

Identification tools

Comparison Occurrence Trend

I

Riverine input of DIN and DIP t/year Annual total √TN µg/L or µM Annual mean √ √TP µg/L or µM Annual mean √ √

DIN /L M A l √ √DIN µg/L or µM Annual mean √ √DIP µg/L or µM Annual mean √ √

DIN/DIP ratio - Annual mean √ √

Maximum of Chl a µg/L Annual maximum √ √

II

Maximum of Chl a µg/L Annual maximum √ √

Mean of Chl-a µg/L Annual mean √ √

Red tide events (diatom sp.) Time/3 year Annual occurrence √ √

√ √Red tide events (flagellate sp.) Time/3 year Annual occurrence √ √

IIIDO (Bottom) mg/L Annual mean √ √

COD mg/L Annual mean √ √ Fi h kill i id t Ti /3 A l √ √Fish kill incidents Time/3 year Annual occurrence √ √

IV

Red-tide events(Noctiluca and Mesodinium sp.) Time/3 year Annual occurrence √ √

IVShellfish poisoning incidents Time/3 year Annual total √ √

13

3 23 2 SettingSetting of reference concentrationsof reference concentrations3.2 3.2 Setting Setting of reference concentrationsof reference concentrations

Classification of Chinese standard of national seawater qualityParameters

Classification of Chinese standard of national seawater quality

I II III IV

DIN ( l 1) 0 2 0 3 0 4 0 5DIN (mg l-1) 0.2 0.3 0.4 0.5

DIP (mg l-1) 0.015 0.03 0.045

COD (mg l-1) 2 3 4 5

Cl II t th f t ti f th t i thClass II was set as the reference concentrations of the assessment, since the Jiaozhou Bay is an important water body for aquaculture, tourism.

Thresholds of DO and Chl.a were set according to relative research and international criteria (Yao et al., 2007; Xia et al., 2012; Bricker et al., 2003).

Thresholds of TN, TP are set based on Japan Environmental water quality standard Type III and Fishery Type 2. yp y yp

14

Summation of assessment criteriaSummation of assessment criteria

Category Parameters Reference concentrations References

TN 0.6 mg l-1 (42.9 μM) Japan Fishery Type 2

I

TP 0.05 mg l-1 (1.61μM) Japan Fishery Type 2

DIN 0.3 mg l-1 (21.4 μM) NSQS Class II

DIP 0 03 l-1 (0 97 M) NSQS Cl IIDIP 0.03 mg l-1 (0.97μM) NSQS Class II

DIN/DIP ratio 16 Redfield Value

Maximum of Chlorophyll a 20μg l-1 Bricker et al., 2003

II Mean of Chl-a 5 μg l-1 Yao et al., 2007; Xia et al., 2012

Red tide events(Diatom and flagellate species) 1 event/3 years CEARAC Report 2011

III

DO (bottom) 2 mg l-1 Bricker et al., 2003

COD 3 mg l-1 NSQS Class II

Fish kill incidents 1 event/3 years CEARAC Report 2011

IV

Red-tide events (Noctiluca and Mesodinium sp.) 3 event/3 years CEARAC Report 2011

IVShellfish poisoning incident 1 event/3 years CEARAC Report 2011

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4.1 Assessment of Category Ig yRiverine input of DIN and DIPTN and TPDIN and DIPDIN/DIP

(1) Riverine input of DIN and DIP in Sub-area A

Trend: Increasing based gon linear regression analysis.

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(2) Annual average of TN and TP

TN TP

No trend No trend

Sub-area A Sub-area A

Higher No trendHigher

No trendLower

No trendHigher

Sub-area B Sub-area B

Lower Higher

No trendHigher

No trendHigher

Sub-area C Sub-area C

g

18

(3) Annual average of DIN and DIP

DIN DIP

Sub-area A Sub-area AIncreasingHigher

IncreasingHigher

N t d


IncreasingNo trendLower

gHigher

No trend


IncreasingLower Higher

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(4) DIN/DIP

Sub-area ADecreasingHigher

Sub area A

Sub-area B

DecreasingLLower

Sub-area C

DecreasingLower

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Parameters Ranges of z value p value Overall trend

Summation of trend analysis for category ISummation of trend analysis for category IParameters Ranges of z value p value Overall trend

Riverine input DIN — — Increasing (linear regression)

Riverine input DIP — — Increasing (linear regression)

TN (Sub-area A) -1.5206 to 1.4032 All > 0.05 No trend

TN (Sub-area B) -0.1830 to – 0.4889 All > 0.05 No trend

TN (Sub-area C) -1.1591 to - 0.2440 All > 0.05 No trendN (Sub a ea C) No t e d

TP (Sub-area A) 0.1830 – 1.6472 Most >0.05 No trend

TP (Sub-area B) 0.1222 – 1.2225 All >0.05 No trend

TP (Sub-area C) 0 – 1.2859 All >0.05 No trend

DIN (Sub-area A) 1.647-3.111 All <0.05 Increasing

DIN (Sub-area B) 1.159-1.525 All >0.05 No trend

DIN (Sub-area C) 0.305-0.427 All >0.05 No trend

DIP (Sub-area A) 3.355-3.966 All <0.05 Increasing

DIP (S b B) 3 477 3 667 All 0 05 I iDIP (Sub-area B) 3.477-3.667 All <0.05 Increasing

DIP (Sub-area C) 2.989-3.056 All <0.05 Increasing

DIN/DIP ratio (Sub-area A) -2.623 to -0.798 Most <0.05 Decreasing

DIN/DIP ratio (Sub-area B) -2.989 to -2.379 All <0.05 Decreasing

DIN/DIP ratio (Sub-area C) -3.355 to -2.623 All <0.05 Decreasing21

4.2 Assessment of Category II: Chlorophyll a and Red tide events

(1) Maximum of Chl-a (2) Mean of Chl-a

No trendL

No trend

Sub-area A Sub-area A

Lower Lower

No trendLower No trend


LowerLower

No trendLower

No trendLower


Lower Lower

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(3) Red tide events (Diatom) (4) Red tide events (flagellate)

Decreasing trend in recent 13 years

Sub-area A

yLow (no event in recent 3 years)

Sub-area A

No obvious trend in recent 13 yearsHigh (1 incidence occurred in

Sub-area A

Low (no event in recent 13 years)

Sub-area B

recent 3 years)

Sub-area C

Low (no red tide (flagellate) events occurred in Sub-area B and C)

Sub area C

Increasing trend in recent 13 yearsHigh (more than one

Sub-area B and C

g (event (2 times) in recent 3 years)

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Summation of trend analysis for category IISummation of trend analysis for category II


Summation of trend analysis for category IISummation of trend analysis for category II

Max Chl-a (A) -1.55to 0.6 All >0.05 No trend

Max Chl-a (B) -0.77 to -0.31 All >0.05 No trend

Max Chl-a (C) -0.17 >0.05 No trend

Mean Chl-a (A) -2.12 to -0.48 Most >0.05 No trend

Mean Chl-a (B) -1.98 to -1.44 All >0.05 No trend

Mean Chl-a (C) -1.44 to -0.311 All >0.05 No trend

R d tid t (Di t ) (A) 1 5699 <0 05 D i t dRed tide events (Diatom) (A) -1.5699 <0.05 Decreasing trend

Red tide events (Diatom) (B) — — —

Red tide events (Diatom) (C) 2 0831 <0 05 Increasing trendRed tide events (Diatom) (C) 2.0831 <0.05 Increasing trend

Red tide events (flagellate) (A) 1.2026 >0.05 No trend

Red tide events (flagellate) (B) — — —

Red tide events (flagellate) (C) — — —

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4.3 Assessment of Category III: DO, COD and Fish kill incidents

(1) DO (Bottom) (2) COD

IncreasingHigher

Sub-area A

No trendLower

Sub-area A

g Lower

Sub-area BIncreasingHi h

No trend

Sub-area B

Higher Lower

Sub-area C

IncreasingHigher

No trendLower

Sub-area C

Higher Lower

25

(3) Fish kill incidents

There were no records for Fish kill incidents in all three sub-areas from 1997 to 2009.

( )

Trend: No trendOccurrence: Low

Summation of trend analysis for category IIISummation of trend analysis for category III


Summation of trend analysis for category IIISummation of trend analysis for category III

Bottom DO — — Increasing trend (linear regression)

COD (Sub-area A) 0-1 711 Most >0 05 No trendCOD (Sub area A) 0 1.711 Most >0.05 No trend

COD (Sub-area B) 0.06-0.305 All >0.05 No trend

COD (Sub-area C) 0.549-1.15 All >0.05 No trend

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4.3 Assessment of Category IV: Red-tide events and Shellfish poisoning

(1) Red tide events (Noctiluca sp And

incidents

(1) Red-tide events (Noctiluca sp. And Mesodinium sp.) in the sub-areas

Sub area A

No trendNo occurrence in the last 3 years

Sub-area A

No trendSub-area B

No trendNo occurrence in the last 3 years

No trendSub-area C

three incidence in the last 3 years

27

(2) Shellfish poisoning incidents

There were no records for shellfish poisoning incidents in all three sub areas from 1997 to 2009three sub-areas from 1997 to 2009.

Trend: No trendOccurrence: LowOccurrence: Low

Summation of trend analysis for category IVSummation of trend analysis for category IV


Red-tide (Noctiluca and Mesodinium sp.)(A) -0.8882 >0.05 No trend

Red-tide (Noctiluca and Mesodinium sp.) (B) -0.4009 >0.05 No trend

Red-tide (Noctiluca and Mesodinium sp.) (C) 1.5266 >0.05 No trend( p ) ( )

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5.1 Assessment summary for Sub-area A

Category Assessment parameter Comparison Occurrence Trend Parameteridentification

Categoryidentification

Riverine DIN × × I I

I HI

Riverine DIP × × I ITN H × N HNTP H × N HN

DIN H × I HIDIP H × I HI

DIN/DIP ratio H × D HDN/ at o

II

Max of Chl-a L × N LN

LNMean of Chl-a L × N LN

Red tide events (Diatom) × L D LDRed tide events (Diatom) × L D LDRed tide events (flagellate) × H N HN

IIIDO (bottom) L × D LD

LNCOD L N LNIII LNCOD L × N LNFish kill incidents × L N LN

Red-tide events (Noctilucaand Mesodinium sp.) × L N LN

IV and Mesodinium sp.) LNShell fish poisoning incidents × L N LN

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5.2 Assessment summary for Sub-area B

Category Assessment parameter Comparison Occurrence Trend Parameteridentification

CategoryIdentification

Riverine DIN × ×Ri i DIP

I LN

Riverine DIP × × × ×TN L N LNTP H N HN

DIN L × N LNDIP H × I HI

DIN/DIP ratio L × D LD

II



Red tide events (Diatom) × L N LNRed tide events (Diatom) L N LN

Red tide events (flagellate) × L N LNDO (bottom) L × D LD

III LNCOD L × N LNFish kill incidents × L N LN

Red-tide events (Noctiluca × L N LNIV and Mesodinium sp.) × L N LN

LNShell fish poisoning incidents × L N LN

31

5.3 Assessment summary for Sub-area CParameter CategoryCategory Assessment parameter Comparison Occurrence Trend Parameter

identificationCategory

identificationRiverine DIN loads × × × ×

Riverine DIP loads × × × ×

I HN

Riverine DIP loadsTN H × N HNTP H × N HN

DIN L × N LNDIN L × N LNDIP H × I HI

DIN/DIP ratio L × D LDM f Chl L N LN

II



Red tide events (Diatom) × H I HIRed tide events (flagellate) × L N LN

III

DO (bottom) L × D LD

LNCOD L × N LNIII LNFish kill incidents × L N LN

Red-tide events (Noctilucaand Mesodinium sp ) × H N HN

IV and Mesodinium sp.) HN-LNShell fish poisoning incidents × L N LN

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ConclusionsConclusions

Nutrients showed an increasing trend in Jiaozhou bay. Especially DIP increase was more serious than DIN. Nutrient enrichment could be a major problem of eutrophication in Jiaozhou Bay which should bemajor problem of eutrophication in Jiaozhou Bay, which should be concerned in the future.

So far, we didn’t observe significant direct and indirect effects due toSo far, we didn t observe significant direct and indirect effects due to nutrient enrichment in the bay. The eutrophication symptom was weaker and the degree was lower.

Comparatively, red tide events (Noctiluca.sp and Mesodinium sp.) were more frequent in outside than inner of Jiaozhou bay. It may be relative to shellfish aquaculture in inner of the bay. Shellfish are q yfilter-feeding animals that can suck redtide species out of the waters.

SuggestionSuggestion

Harmonized and universal reference of parameters should be recommended in order to compare eutrophication status in different

SuggestionSuggestion

recommended in order to compare eutrophication status in different areas.

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jiaozhou bay (china-yu)dip 0030.03 mg l-1 (0970.97μm) nsqs cl iiclass ii din/dip ratio 16 redfield...

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