Regional Analysis on Decadal Variation in Aspects of Water Quality in Three Contrasting Coastal...

Hindawi Publishing CorporationISRN OceanographyVolume 2013 Article ID 652617 11 pageshttpdxdoiorg1054022013652617

Research ArticleRegional Analysis on Decadal Variation in Aspects ofWater Quality in Three Contrasting Coastal Systems ofIshikawa Coast Japan

J I Agboola12 and A E McDonald1

1 Operating Unit in IshikawaKanazawa Institute of Advanced Studies United Nations University 2-1-1 Hirosaka KanazawaIshikawa 920-0962 Japan

2Department of Fisheries Faculty of Science Centre for Environment and Science Education (CESE) Lagos State UniversityPMB 0001 LASU Ojo Lagos Nigeria

Correspondence should be addressed to J I Agboola jb agboolayahoocom

Received 26 December 2012 Accepted 15 January 2013

Academic Editors C W Brown and C-C Hung

Copyright copy 2013 J I Agboola and A E McDonald This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

This study examines drivers and trends of change in time and space in some coastal water quality parameters and manage-mentcultural practices on the Ishikawa coast Japan between 1984 and 2009 Generally chemical oxygen demand (COD) anddissolved oxygen (DO) concentrations varied significantly (119875 lt 0001) across the three coastal compartments (Kanazawa area(KNA) Noto area (NTA) and Nanao area (NNA)) and pH and DO concentrations varied significantly (119875 lt 0001) over the lastthree decades suggesting that human perturbation within the last three decades varied along the coast and may be more relativethan environmental change impact Other water quality variables showed different spatial and temporal patterns and implicationsacross the coastal compartments Although there is a uniform approach to the development of water quality standards in Japanthese results suggest that setting stricter standards may be required by the prefectural government in collaboration with industrystakeholders groups and coastal community resource users

1 Introduction

Often rapid population growth and economic and infras-tructural development have caused the large-scale exploita-tion of coastal resources and resulted in severe degradationand declination of the quality of the coastal environmentIntensive agriculture and coastal engineering such as artifi-cial inlets promote some undesirable changes in coastal sys-tems [1] It is perceived that these pressures on coastal zoneswill certainly be more intense in the future Water qualityproblems in estuaries and coastal areas are currently insertedat a regional scale [2] and continuous field observation datawill advance our knowledge of possible future human impacton the coastal environment [3] Thus decadal analysis oftrends and drivers of change in nearshore ocean ecosystemsat regional scale will be required to predict impacts of changein the worldrsquos coastal zone

Stretching along the Sea of Japan the Ishikawa coast(Figure 1) benefits from a number of diverse and contrastingcoastal zone ecosystems exhibiting different physiographictopographic and geomorphologic characteristics From thenorthern (Noto) to southern (Kaga) districts a large percent-age of Ishikawarsquos population depends on coastal and marineecosystems and resources for their livelihoods and majorsocioeconomic activities like fisheries tourism shippingand agriculture depend on these resources The Noto areain particular is acclaimed as one of the largest fisheriesdevelopment ports in Japan Over the years however thecoastline has experienced rapid and serious erosion andcoastal habitat loss due to the combined effects of naturaland anthropogenic factors [4] Environmental problems inthe marine and coastal areas along the Sea of Japan havebeen reported to include land-based sources of pollution oilspills and coastal alterations including land reclamation and

2 ISRN Oceanography

excessive groundwater extractions [5ndash8] In this study wefound that in the last three decades there were significantspatial and temporal changes in some water quality parame-ters Therefore it is expected that with the significant spatialdifferences in land use and human impact along the coastcoastal water quality may continue to degrade in the absenceof effective positive policy drive

Along the Ishikawa coast patches of documented fieldwater-quality monitoring data date back to 1974 Here weevaluate the degree of water quality change on the Ishikawacoast from documented in situ water quality measurementsdata (DO COD pH temperature T-N and T-P) providedby the EnvironmentDepartment IshikawaPrefecturalOfficeJapan (Ishikawa Prefecture Annual Report of the WaterQuality from Underground Water and Public Water) ourfield observations and interviews

Lastly the aims of this study were to analyze anddocument trends of change in some coastal water qualityparameters using ground-based data from three contrastingcoastal systems of Ishikawa coast and to deduce some naturaland anthropogenic drivers of change From the point of viewof water quality it hopes to explore vulnerable areas on thecoast and to document implication of changes on the long-term sustainability of Ishikawa coastal ecosystems

2 Study Area Description

The present study area Ishikawa coast is located on the mid-dle north of Japan and lies between 36∘171015840N to 37∘521015840N lat-itude and between 136∘141015840E to 137∘211015840E longitude (Figure 1)The coastline has a general NE-SW orientation [4] and thecoastline has sim581 km alongshore stretch with significantlydifferent physiographies and topographies from northern(Noto) to southern (Kaga) districtThis study area is classifiedinto three coastal compartments based on the significantcontrasting physiographic (physical characteristics) changesalong the coastline and the need to explore the driversand mechanisms of change The first coastal compartmentmdashKanazawa area (hereafter KNA)mdashis an exposed bay notedas a large littoral cell stretching approximately 75 km alongthe Japan Sea Coast [4] on the southern coast (between southKaga and Hakui) and features sandy beaches shorelines andstrong sea waves of the Sea of Japan The second coastalcompartment is the Noto area (hereafter NTA) an exposedbay located on the northern coast (between Shika and Notoend of Suzu) dotted with sheer cliffs and unusual rockformations and also characterized by high and intense seawaves of the Sea of Japan This coastal compartment (NTA)is acclaimed one of the largest fisheries development ports inJapan The Nanao area (hereafter NNA) is the third coastalcompartment (from Noto town down to Nanao) a calmercoast facing Nanao Bay blessed with a fine harbor protectedagainst strong south andwest winds and has a thriving fisherywith an average annual fish catch of approximately 1000metric tons in recent years It is an enclosed bay and featuresboth sandy beaches and rocky shorelines

Generally Ishikawarsquos climate is strongly influenced by theTsushima warm water current and winter wind causing awide variety of seasonal environments It can be described as

being humid wet and hot in summer and rainy and receivinglots of snow in winter

3 Materials and Methods

This study is based on decadal and comparative analysisof existing records and in situ measurements data of somewater quality parameters on the Ishikawa coast obtainedfrom the Water Quality Monitoring Unit EnvironmentDepartment Ishikawa Prefectural Office Japan and fromfield observations and interviews Consistent water qualitydata was available from 33 stations designatedmdashKNA (20)NTA (6) andNNA (7)mdashand sampled (0-1mdepth) along thecoastal zone (lt5 km from shoreline) of Ishikawa between 1974and 2009 Nutrient data were available only at five stationscharacterized by strong human influence riverine dischargeand enclosed coastal ecosystems at KNA (2 stations) andNNA (3 stations) coastal compartments Here we analyzedfor trends and possible drivers of change in some waterquality parameters dissolved oxygen (DO) chemical oxygendemand (COD) an environmental quality standard (EQS)for the conservation of the living environment and typicalwater quality indicators for organic contaminant hydrogenion concentration (pH) total nitrogen (T-N) and totalphosphate (T-P) on a five-year interval between 1984 and2009 at the three coastal compartments (KNA NTA andNNA)

31 Sampling and Analysis Water samples were collectedannually with monthly and station sample size (119899) range10ndash12 and 30ndash33 respectively Temperature pH and DOwere measured in situ using calibrated portable meterswhile water samples were analyzed in the laboratory forCOD (colorimetric) T-N and T-P Nutrient concentrationswere measured according to [10] between 1980s and early90s immediately after sampling and from mid-1990s to2009 nutrient concentrations were measured with Bran andLuebbe Auto Analyser Traacs 800 after storage at minus20∘C

32 Statistical Analysis Variations in surface water qualityparameters (DO COD pH temperature T-N and T-P) werecompared for the three coastal compartments (KNA NTAand NNA) across three decades (between 1984 and 2009)using a two-way analysis of variance (ANOVA) whereasthe Duncan multiple range test was used for separation ofmeans Intercorrelation of variables was investigated usingthe Pearson product-moment correlations coefficient

4 Results

41 Spatial and Temporal Variation in Environmental Vari-ables Mean annual distribution of rainfall and atmospherictemperature between 1930 and 2010 across the three coastalcompartments (KNA NTA and NNA) on Ishikawa coastare presented in Figures 2(a) and 2(b) Mean annual rainfallvalues over the last eight decades showed highly significant(119875lt0001) temporal and spatial variation across the Ishikawaprefecture (KNA NTA and NNA)Themean annual rainfall

ISRN Oceanography 3

NNANTA

KNAIshikawa prefecture 0 20 4010

(km)

N

Figure 1Map of study area showing sampling stations at KNANTA andNNA coastal compartments on Ishikawa coast Ishikawa PrefectureJapan

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 20200

500

1000

1500

2000

2500

3000

3500

Mea

n an

nual

rain

fall

(mm

)

Period (yr)

KNANTANNA

(a)

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

KNA

NNA

0

4

8

12

16

20

Mea

n an

nual

tem

pera

ture

(∘C)

Period (yr)

NTA

(b)

Figure 2Mean annual rainfall (a) and temperature (b) distribution at KNANTA andNNAcoastal compartments on Ishikawa coast between1930 and 2010

values (range 1304ndash3307mm) peaked at KNA (3307mm) in1985 and within the last four decades had minimum value(1304mm) recorded at NNA The mean annual atmospherictemperature increased by sim22ndash35∘C between 1930 and 2010across the Ishikawa prefecture and the annual mean tem-perature maximum (159∘C) was recorded in 2010 at NTATemporal and spatial analysis revealed highly significant (119875lt0001) decadal change in the atmospheric temperature fromnorthern Noto to southern Kaga districts in the Ishikawaprefecture

42 Water Quality Variables and Values ofIn Situ Measurements

421 Temporal Variation inWater Quality Variables Annualmean values of water quality variables computed on a five-year interval from 1984 to 2009 are shown in Table 1 FromANOVA analysis water quality variables (DO and pH)showed highly significant (119875 lt 0001) variation In theexamined years DO and pH values showed some markedvariations (Figures 3(a) and 3(b)) Along the coast mean

4 ISRN Oceanography

0

1

2

3

4

5

6

7

8

9

10

11D

issol

ved

oxyg

en D

O (m

gL)

1984 1989 1994 1999 2004 2009Period (yr)

(a)

75

76

77

78

79

8

81

82

83

84

85

86

Hyd

roge

n io

n co

ncen

trat

ion

(pH

)

1984 1989 1994 1999 2004 2009Period (yr)

(b)

KNANTANNA

002040608

112141618

2222426

1984 1989 1994 1999 2004 2009

Chem

ical

oxy

gen

dem

and

CO

D (m

gL)

Period (yr)

(c)

Figure 3 Temporal variation of dissolved oxygen (DO) (a) hydrogen ion concentration (pH) (b) and chemical oxygen demand (COD) (c)at KNA NTA and NNA coastal compartments between 1984 and 2009 on Ishikawa coast

DO values ranged between 776mgL (1989) and 978mgL(1984) whilemean pH values ranged between 820 (2009) and843 (1984) indicating a significant drop (sim023 units) in pHvalues within the last three decades In contrast the meanconcentration of COD was not statistically different (119875 gt005) over the years as both maximum (190 plusmn 063mgL)and minimum (100 plusmn 050mgL) COD concentrations wererecorded in 1984 (Figure 3(c))

422 Spatial Variation in Water Quality Variables Withinthe last three decades COD mean concentration hasdecreased by sim20 between 1984 (190 plusmn 063mgL) and2009 (154plusmn037mgL) at KNA coastal compartment Similarreduction trend was observed at NNA asmean concentration

decreased by sim12 between 1984 (135plusmn077mgL) and 2009(119 plusmn 032mgL) (Table 1) In contrast NTA which hadlowest COD concentration in 1984 (100 plusmn 050mgL) hadincreased by one-fourth (sim25) as at 2009 (132plusmn031mgL)possibly as a result of human perturbation from tourism andagricultural and fishing activities In the years reported in thisstudy dissolved oxygen concentration spatially varied alongthe Ishikawa coast even thoughmaximum (978plusmn062mgL)and minimum (776 plusmn 028mgL) DO concentration wererecorded at NTA (Figure 3(a))

Furthermore in the last three decades pH values havedropped between 013ndash020 units along the coast (KNANTAandNNA) possibly suggesting environmental change impacton coastal waters quality of Ishikawa At KNA maximum pH

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Table 1 Mean plusmn SD of some water quality parameters at KNA NTA and NNA areas on Ishikawa coast

Area Parameters 1984 1989 1994 1999 2004 2009Temperature (∘C) 1690 plusmn 81a 1777 plusmn 750a 1908 plusmn 900a 1866 plusmn 780a 1895 plusmn 860a 1900 plusmn 610a

T-N (mgL) 098 plusmn 020a 088 plusmn 020a 079 plusmn 010a 069 plusmn 030a 074 plusmn 020a 065 plusmn 030a

KNA T-P (mgL) 009 plusmn 000b 010 plusmn 000b 007 plusmn 000a 005 plusmn 000a 007 plusmn 000a 005 plusmn 000a

DO (mgL) 805 plusmn 036b 787 plusmn 034a 822 plusmn 016b 860 plusmn 022c 922 plusmn 024e 901 plusmn 024d

pH 843 plusmn 009c 833 plusmn 007b 831 plusmn 007b 833 plusmn 006b 830 plusmn 007b 825 plusmn 008a

COD (mgL) 190 plusmn 063b 138 plusmn 044a 168 plusmn 064ab 158 plusmn 038ab 160 plusmn 047ab 154 plusmn 037a

DO (mgL) 978 plusmn 062d 776 plusmn 028a 832 plusmn 025b 886 plusmn 027bc 916 plusmn 023c 874 plusmn 012bc

NTA pH 840 plusmn 012c 830 plusmn 000b 830 plusmn 000b 838 plusmn 005bc 830 plusmn 000b 820 plusmn 007a

COD (mgL) 100 plusmn 050a 110 plusmn 007a 112 plusmn 013a 136 plusmn 013a 128 plusmn 018a 132 plusmn 034a

Temperature (∘C) 2020 plusmn 816a 2222 plusmn 398a 1962 plusmn 735a 2120 plusmn 772a 1911 plusmn 638a 1836 plusmn 700a


NNA T-P (mgL) 002 plusmn 001a 003 plusmn 003a 002 plusmn 001a 003 plusmn 003a 005 plusmn 011a 002 plusmn 001a

DO (mgL) 863 plusmn 063bc 802 plusmn 014a 841 plusmn 016b 881 plusmn 030bc 889 plusmn 024c 870 plusmn 025bc

pH 837 plusmn 013c 834 plusmn 005bc 827 plusmn 005ab 837 plusmn 005c 829 plusmn 004ab 824 plusmn 005a


Values of respective area and year along the same row bearing the same superscripts are not statistically different at 5 probability level using the Duncanmultiple range test For each area and year data (except for T-N and T-P) were pooled from sampling stations (119899 size 30ndash33) and months (119899 size 10ndash12)respectively to obtain the mean plusmn SD Sea water temperature T-N and T-P data were not available for NTA

value dropped gradually from 843 in 1984 to 825 in 2009(Figure 3(b)) Similar trend was observed at NTA and NNAwith pH drop of 020 and 013 units respectively between1984 and 2009

In general while COD andDO concentrations varied sig-nificantly (119875 lt 0001) across the three coastal compartments(KNA NTA and NNA) there was no significant variation(119875 gt 005) in pH along the coast Also while pH andDO concentrations varied significantly (119875 lt 0001) overthe last three decades there was no significant (119875 gt 005)change in COD concentration (Figure 3(c)) suggesting thathuman perturbation over the years may bemore relative thanenvironmental change impact

423 Spatial and Temporal Variation of Nutrient Concen-trations and Temperature The range of nutrients (T-N andT-P) concentration and sea water temperature within thelast three decades at KNA and NNA is presented in Table 1Nutrients concentration and seawater temperature profileacross the examined periods were relatively homogenous inthe two coastal compartments An exception is T-P nutrientconcentration at KNA Mean values recorded over the yearswere not statistically different at 5probability level using theDuncan multiple range test While total nitrogen (T-N) andtotal phosphate (T-P) loading have significantly reduced bysim30ndash45 between 1984 and 2009 at KNA there has not beensignificant reduction at NNA suggesting a coastal systempotentially vulnerable to eutrophication possibly due to oftenrestricted water exchange with the adjacent ocean riverrunoff and shore andor shallow sediment abrasion Alsothe relationship between T-N and T-P and their distributionalong the Redfield ratio line (N P = 16 1) at KNA andNNA isshown in Figures 4(a) and 4(b) Corresponding T-N and T-Pvalues were distributed often above the Redfield ratio line atKNA and around (above and below) the Redfield ratio line at

Table 2 Pearsonrsquos correlation matrix of some water quality param-eters at KNA NTA and NNA on Ishikawa coast

DO pH COD Year AreaDO 1pH minus0086 1COD 0066 0359lowastlowast 1Year 0548lowastlowast minus0502lowastlowast minus0026 1Area 0107 0012 minus0249lowastlowast minus0016 1lowastlowastCorrelation is significant at the 001 level (2-tailed)

NNA These distribution patterns of nutrient concentrationsuggest some potential limitation of T-N nutrient at KNAand T-P nutrient at NNA Nutrient-flux ratio (N P ratio)distribution at KNA and NNA exhibited annual fluctuations(Figure 5) with ratio values exclusively lt16 1 at KNA (NPmin 60 NP max 158) Although N P ratios varied widelyand are largely distributed close to the 16 1 at NNA optimalalgal growth ratio as indicated by the Redfield ratio [9]

424 Intercorrelation of Spatial and Temporal Water QualityVariables The intercorrelation amongwater quality variables(pH COD and DO) in relation to the examined periods andcoastal compartments (Table 2) revealed a significant positivecorrelation (119903 = 0359 119875 = 0001 119899 = 191) betweenpH and COD Across the examined years DO showed apositive and highly significant correlation (119903 = 0548 119875 =0001 119899 = 191) whereas pH showed a negative and highlysignificant correlation (119903 = minus0502 119875 = 0001 119899 = 191)suggesting that while pH value has decreased significantlyover the years DO has been on the increase Of the waterquality variables (pH COD and DO) only COD showed asignificant negative correlation (119903 = minus0249 119875 = 001 119899 =191) with the three coastal compartments Using the Pearson

6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)

Figure 4 Relationship between T-N and T-P at KNA (a) andNNA (b) coastal compartments between 1984 and 2009 on Ishikawa coast Darkthin line is linear regression and dark thick line is the Redfield et al [9] ratio (N P = 16 1)

0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA

Figure 5 N P molar ratio distribution at KNA and NNA coastalcompartments between 1984 and 2009

product moment correlations coefficient (table not shown)we further elucidate on the dynamics of water quality changeat the different coastal compartments At KNA DO showedan increasing and highly significant (119903 = 0810 119875 = 00001119899 = 119) trend over the years and significantly correlated(119903 = 0222 119875 = 005 119899 = 119) with COD whereas atNTA there was no significant correlation with COD and overthe years While DO showed a less significant (119903 = 0374119875 = 005 119899 = 42) increase over the years at NNA there wasno significant correlation with COD Spatially COD showeda positive significant correlation (119903 = 0420 119875 = 005

119899 = 30) only at NTA suggesting an increasing trend over theyears Highly significant correlation of DO and pH variablesover the years suggests their relative importance to decadalvariation on Ishikawa coast towards predicting current stateand future status of coastal water quality that may requirepolicy response Since only COD showed significant corre-lation with the three coastal compartments it suggests thathuman impacts vary along the coastline and warrants furtherinvestigation local attention and adequate policy response

425 Intercorrelation of Nutrient Concentration and Temper-ature at KNA and NNA We evaluate the relations betweenT-N T-P and temperature variables using Pearson prod-uct moment correlations coefficient Temporally there washighly significant correlations (119903 = 0467119875 = 00001 119899 = 93)between T-N and T-P whereas no significant relationshipwas established between temperature and nutrients over theexamined period when data from the two coastal compart-ments (KNA and NNA) were pooled for Ishikawa coast(Table 3) However a negative highly significant correlation(119903 = minus0676 119875 = 00001 119899 = 24) was observed betweentemperature and T-N Also there was significant inversecorrelation of T-N (119903 = minus0490 119875 = 001 119899 = 24)and T-P (119903 = minus0708 119875 = 00001 119899 = 24) with KNAcoastal compartment (table not shown) All these suggest thatnutrientsrsquo loading on Ishikawa coast has decreased over theyears however further monitoring may be required at NNAan enclosed coastal compartment

5 Discussion

Results from this study on regional analysis of decadal vari-ations in water quality along Ishikawa coasts revealed somelevel of significant (00001 ge 119875 le 005) changes across spaceand time in some water quality variables Observed spatialpattern indicates that coastal developments varying levelsof socioeconomic activities and perhaps physical processes

ISRN Oceanography 7

Table 3 Pearsonrsquos correlation matrix of nutrients and temperatureat KNA and NNA on Ishikawa coast

Temperature T-N T-P Year AreaTemperature 1T-N minus0172 1T-P 0055 0467lowastlowast 1Year minus0057 minus0096 minus0024 1Area 0105 minus0832lowastlowast minus0386lowastlowast 0017 1lowastlowastCorrelation is significant at the 001 level (2-tailed)

such as water residence time shore andor shallow sedimentabrasion river runoffs and climate change are factors thatplay an important role in promoting change in the coastalzone Due to the influences of human activities within onlya few decades numerous previously pristine oligotrophicestuarine and coastal waters have undergone a transforma-tion to more mesotrophic and eutrophic conditions [11ndash13]promoting space-time variation in water quality

Over the last eight decades (1930ndash2010) mean annualrainfall and atmospheric temperature revealed a highly sig-nificant (119875 lt 00001) decadal change and dynamic spatialpattern from northern Noto (NTA and NNA) to southernKaga (KNA) districts in Ishikawa prefecture As a result ageneral description of the Ishikawa coastal climate may becomplex and may partly influence the spatial dynamics insome water quality parameters

Chemical oxygen demand (COD) a typical water qualityindicator for organic contaminant and an environmentalquality standard (EQS) for the conservation of the living envi-ronment revealed more of a spatial than temporal variationon the Ishikawa coast For instance COD maximum (190 plusmn063mgL) and minimum (100 plusmn 050mgL) concentrationswere recorded respectively at KNA andNTA in 1984 Similartrend was observed in other years suggesting that spatialvariation pattern was more significant on the Ishikawa coastpossibly due to differences in human perturbation levelsOnly COD water quality variable showed significant correla-tion (at 1 probability level) with the three coastal compart-ments (Table 3) suggesting that anthropogenic impacts varyalong the coastline and may warrant further investigationand adequate policy response Thus variations in organiccontamination pattern is rather spatial than temporal alongthe Ishikawa coast andmay have implication on coastal livingresources

51 Ecological Response to DO pH and Nutrients Generallysurface DO concentrations varied significantly (119875 lt 0001)over the last three decades and across the three coastalcompartments (KNA NTA and NNA) Decrease in DOconcentration as observed between 2004 and 2009 especiallyat KNAandNNAwas hypothesized to be driven primarily bychanges in ocean circulation and less by changes in the rate ofO2demand from downward settling of organic matter since

there was a corresponding decrease in COD concentrationOn the Japan Sea [14] report a large long-term decreasein the oceanic O

2concentration of more than 20120583mol kgminus1

since the mid-1950s [15] analyzed GEOSECS and WOCE

data to calculate basin-wide changes for the North PacificThey find a decrease in dissolved O

2in the upper ocean

and an increase in the deep Decreasing O2concentrations

were also reported by [16 17] in subsurface water in thewestern subarctic Pacific between 1968 and 1998 and by [18]analyzing data of four different cruises in the North Pacificduring the 1980s and 1990s The observation-based analysesidentify ocean circulation changes as the main cause of theobserved decrease in dissolved O

2[14ndash20]

Although near-surface changes in O2concentration are

difficult to interpret as observed changes cannot be explainedby known processes changes in O

2can be caused by changes

in biological activities changes in the physical transport ofO2from intermediate waters or by changes in temperature

and salinity [21] In this study possible influence of temper-ature on O

2solubility was not considered since there is no

significant correlation (119875 gt 005) between temperature andO2 Also we lacked data to suggest the possible influence

of phytoplankton activity on dissolved oxygen Along theIshikawa coast dissolved oxygen (DO) concentrations weresignificantly higher than 50mgL suggested as acceptablefor most aquatic organisms [22] Also according to [23]environmental dissolved oxygen levels must be high enoughto support aerobic metabolism in fishes Thus the DOconcentration obtained from this study suggests that thecoastal ecology of Ishikawa could support growth and repro-duction of living resources as observed in the thriving fisheryindustries along the coastline especially at NTA and NNA

Within the last three decades trend analysis showed thathydrogen ion concentration (pH) value has dropped between013ndash020 units along the coast (KNA NTA and NNA) andsim023 units between 1984 and 2009 leading to an increasein water column acidity and suggesting possible environ-mental change impact on coastal water quality of IshikawaWhile phytoplankton activity may strongly influence pHwe consider that most marine plants (with the exception ofseagrasses) are carbon-saturated [24] and enhanced growthis not expected Increased CO

2concentrations lower ocean

pH which in turn changes ocean carbonate chemistry [25]and it is believed that this resulting decrease in pH willhave negative consequences primarily for oceanic calcifyingorganisms When compared with physically driven changessuch as warming and sea level rise the impacts of chemicalchanges in the ocean are poorly understood While increasesin CO

2are expected to have positive impacts on many

terrestrial plants because of increases in photosynthesis [26]as earlier mentioned the reverse may be for carbon-saturatedmarine plants [24] However the reduction in pH thatwill accompany elevated CO

2concentrations has profound

implications for physiological processes inmarine organismsFor example growth and survivorship of gastropods andurchins were reducedwhen exposed to 6months of increasedCO2that resulted in only a pH unit decrease of only 003

[27] Also the population and community level impacts ofsuch changes remain largely unknown Considering that theexpected pH dropmay be unprecedented over the last severalhundred million years and as evident also along Ishikawacoast more research on ecological implications of pH changeis needed In relation to humanhealth however hydrogen ion

8 ISRN Oceanography

(pH) has a direct impact on the recreational users of wateronly at very low or very high values [28]

Furthermore according to [21] changes in nutrientconcentrations can provide information on changes in thephysical and biological processes that affect the carbon cycleand could potentially be used as indicators for large-scalechanges in marine biology Although there was a significantreduction in nutrients concentration at KNA coastal com-partment than at NNA coastal compartment nutrients fluxesare significantly (T-N 119903 = minus0832 119875 = 00001 119899 = 93 T-P 119903 = minus0386 119875 = 00001 119899 = 93) higher at KNA thanat NNA Since most nitrogen loading into aquatic systemshas often been implicated with anthropogenic influenceand sometimes physical forcing drivers of nutrient fluxesalong the Ishikawa coast especially at KNA may be due toincreasing socioeconomic activities and population growthover the years Nutrient impacts on coastal waterways varyas a function of both the loadings (fluxes) and bioavailabilityof the nutrients and the extent to which hydrodynamicfeatures (eg water volumes residence times and extentof mixing) and turbidity levels modulate the stimulatoryeffects of nutrients on plants and algae [29 30] Here resultsof regression analysis carried out to further establish therelationship of nutrients (T-N and T-P) with physical forcingsuch as temperature at KNA and NNA coastal compartmentsrevealed that temperature significantly correlated with nutri-ents concentration especially T-N (119903 = 0438 119875 = 00003119899 = 24) at KNA (figure not shown) while at NNA therewas no significant correlation with nutrient T-N (119903 = 0006119875 = 0244 119899 = 69) We hypothesize that other factorsthan physical forcing may impact on nutrients concentrationand thus foreground the need to determine the effect ofanthropogenic forcing on water quality along the Ishikawacoast

52 Possible Drivers of Change in Coastal Water QualityIncreasing human pressure on the continental margins withexpanding urbanization and the conflicting demands oftourism aquaculture water diversions wind parks and otherdevelopments such as ports have been well documented asdrivers of change in coastal ecosystems [3 4 31 32] Ishikawacoast has experienced significant erosion in recent 100 yearsdue to the combined effect of natural and artificial causesthe shoreline retreats about 200m from 1892 to 1970 [33]As countermeasures against erosion problems constructionof detached or submerged breakwaters started in 1970 withincreased intensity from the mid-1970s to the late 1980 Bythe mid-1990s almost the entire stretch was protected by thisstructure [4]

Along KNA coastal compartment major coastal threat isbeach erosion Erosion is advancing and the sandy beach israpidly disappearing thus becoming a large social problemin Ishikawa In this study most of the nutrient concentrationsshow high levels in southern coastal plain at KNA for thefollowing reasons First the SW and SS shoreline cities likeKanazawa Hakusan and Komatsu are densely populatedwith sizeable industrial centers relative to NTA and NNAcoastal compartments second as mentioned earlier thecoast has experienced rapid and serious erosion due to

the combined effects of natural and anthropogenic factors[34] third the annual net alongshore sediment transportis from NE to the SW near the KNA shoreline [33] andthe development of Kanazawa Port Around NTA coastalcompartment refuse abandonment on the coast by touristhas been identified as one of the drivers of change in thecoastal water quality In the wave of enormous quantity ofrefuse on the coast especially along Shioya to Sogogi coastat NTA community involvement in coastal cleanup waslaunched and has since been sustained

In addition coastal ecosystems like the NNA coastalcompartment may be particularly vulnerable to eutroph-ication due to often restricted water exchange with theadjacent ocean and river runoffs leading to an accumulationof nutrients from the surrounding watershed [1] Marineenvironments subjected to eutrophication are usually thosewith limited mixing capacity The process of eutrophicationis usually rather slow and location specific and becauseeutrophication generally stems from nonpoint sources theprocess may be difficult to legislate and control Eutroph-ication of coastal waters can have a number of adverseimpacts on ecosystems including algal growth hypoxia andsubstantial loss of marine life and habitat [31]

Thus the main vulnerable areas of the coast from thewater quality point of view seem to be the KNA coastalcompartments where high COD concentrations and nutri-ents (T-N and T-P) concentrations are observed AlthoughCOD concentration has been the lowest at NTA relative toKNA and NNA increasing trend observed at NTA in recentyears (Figure 5 and Table 1) suggests some form of organiccontamination possibly as a result of anthropogenic influencewhich may warrant further investigation and local attention

In general surface coastal water quality has improvedwith respect to some pollutants and nutrient loading inJapan as well as Ishikawarsquos ocean coastline However nutrientloading especially in semienclosed bay like the NNA is apotential site for eutrophication

53 Coastal Pollution Problems (Past and Present Status) andPolicy Response Despite the apparent declines in coastalenvironmental quality in Ishikawa in Japan overall thenumber of confirmed sea pollution cases declined by 82from 2460 (of which 2060 are oil-related) in 1973 to 425in 2004 [35] and as reported by the Japan Coast Guard(Figure 6) Although specific data for Ishikawa prefecture isnot reported here it is assumed that this reported trend cutsacross Japan

This decreasing trend of sea pollution has been achievedthrough various programmes since the Marine PollutionPrevention Lawwas enacted in 1970Thedischarge of noxiousliquid substances by ocean-bound vessels has been regulatedby a national law which corresponds to the Protocol of 1978relating to the international convention for the preventionof pollution from ships (the Marpol 7378 protocol) Also awater pollution control law has been enhanced and includesa system to notify specified facilities wastewater regulationcommon to the whole country continuous monitoring ofwater quality a Total Pollutant LoadControl System (TPLCS)for closed sea areas and measures for domestic effluent

ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years

TotalOilOthers (including red tides)

Figure 6 Confirmed cases of sea pollution in Japan (data sourceJapan Coast Guard Ministry of Environment)

More recently in 2008 Japanrsquos Ministry of Environ-ment (MOE) launched the Japan Sea Satoumi Policy Initia-tive working with local municipalities and prefectural andregional government officials Ishikawarsquos Nanao Bay (NNAcoastal compartment in this study) has been selected asone of the four official sites chosen for the Satoumi PilotProject Then in early 2011 MOE formulated the SatoumiGuidelines to aid in the implementation of a national strategyfor ldquocreation of vibrant local communities that make use ofnatural resourcesrdquo One of the main components of this strat-egy includes the ldquodevelopment of abundant Satoumi areasrdquoand other related targets such as conservation restorationand creation of seagrass beds and tidal flats water pollutionmeasures and sustainable resource management

Satoumi has been defined as coastal areas with highproductivity and biodiversity enhanced through humanmanagement It has long sustained not only productive anddistribution activities but also a rich cultureal and intercul-tural exchange and are characterized by rich productivityand biodiversity The integrated management of terrestrialand coastal areas characteristic of Satoumi has contributedimmensely tomaintainingmaterial cycle functions and thusrich and diverse ecosystems and their services

In Japan environmental quality standards (EQS) relatingto living environment including standards for biochemicaloxygen demand (BOD) chemical oxygen demand (COD)and dissolved oxygen (DO) have been established for coastalwater pollution From this study Figures 7(a) 7(b) and 7(c)show the variations of COD DO and pH values from JapanrsquosEQS at KNA NTA and NNA coastal compartments Whilewe consider the dissolved oxygen (DO) a plus being rela-tively higher than Japanrsquos minimum set standards the CODconcentration slightly close to the maximum set standardmay require further attention and monitoring Hydrogen

ion concentration (pH) was slightly higher than maximumset standards and may also require further monitoring toadvance our understanding on possible implication It ishoped that findings from this study will help to promotelocal regional and national policy towards conservationand sustainable management of coastal water quality andresources by solving the problem of alienation of humansfrom the seamdasha challenge to Satoumi

Finally water quality policy which reflects dynamicsocial values and scientific understanding should evolveflexibly to reflect the local context too Thus based on thedynamic spatial characteristics of Ishikawa coastline decisionmakers should ensure that Ishikawarsquos coastal planningzoningaccommodates livelihood and economic changes that accom-pany changing biodiversity and fishing regimes sea-level riseand erosion Although there is a uniform approach to thedevelopment of water quality standards in Japan stricterstandards may be required by prefectural governments incollaboration with industry stakeholders groups and coastalcommunity resource users For such strategies to be mosteffective in maintaining coastal water quality continuousmonitoring of coastal developments and activities shouldtake place

6 Conclusion

Monitoring programs of aquatic systems play a significantrole in water quality control since it is necessary to knowthe contamination degree so as not to fail in the attempt toregulate its impact [32] Documenting long-term changes ofregional coastal ecosystems like the Ishikawa coastal zonesmay be an effective management strategy for sustainableaquatic resource management under current and potentialfuture global environmental change effects Results obtainedfrom this water quality analysis revealed and further but-tressed variability and unsteadiness as intrinsic propertiesof coastal ecosystems where the action of natural forcingfactors is difficult to isolate from anthropogenic ones Whilethis study did not provide a water quality assessment or anoverall process of evaluation of the physical chemical andbiological nature of water in relation to natural quality andhuman effects it has helped to define current conditionsestablished trends on Ishikawa coasts and provided infor-mation on vulnerable area along the coast from view pointof water quality to enable further investigation and possibleprefectural or local government response Effective water-quality monitoring requires actual collection of informationat set locations and at regular intervals in order to providethe data which may be used to define current conditionsand establish trends An attempt therefore to maintainthe coastal water quality through continuous monitoring ofcoastal developments and activities will be a more targetedand effective adaptation strategy

Further studies to this will detail on the socioeco-nomic drivers of current findings and environmental changeimpacts on Ishikawarsquos coastal living resourcesmajorly at KNAand NNA and policy response required for future decisionmaking

10 ISRN Oceanography

02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)

Figure 7 Radar diagram of Japanrsquos environmental quality standards (JapanEQS) in relation to maximum DO (a) pH (b) and COD (c) atKNA NTA and NNA coastal compartments on Ishikawa coast between 1984 and 2009

Acknowledgments

In situ water quality data used in this studywasmade possibleby the long-termwater-qualitymonitoring programme of theEnvironment Unit Ishikawa Prefectural Office Japan Theauthors appreciate the assistance of Ms Akemi Kubota anintern with the UNU IAS OUIK for extracting the data andstaff membersmdashLaura Cocora and Atsuko Hasegawamdashforthe translation of some historical information

References

[1] F U Gonzalez J A Herrera-Silveira and M L Aguirre-Macedo ldquoWater quality variability and eutrophic trends inkarstic tropical coastal lagoons of the Yucatan PeninsulardquoEstuarine Coastal and Shelf Science vol 76 no 2 pp 418ndash4302008

[2] J F Lopes J M Dias A C Cardoso and C I V Silva ldquoThewater quality of the Ria de Aveiro lagoon Portugal from theobservations to the implementation of a numerical modelrdquoMarine Environmental Research vol 60 no 5 pp 594ndash6282005

[3] J I Agboola M Uchimiya I Kudo K Kido and M OsawaldquoDynamics of pelagic variables in two contrasting coastalsystems in the western Hokkaido coast off Otaru port JapanrdquoEstuarine Coastal and Shelf Science vol 86 no 3 pp 477ndash4842010

[4] M Yuhi S Umeda and K Hayakawa ldquoRegional analysis onthe decadal variation of sediment volume in an integratedwatershed composed of the Tedori river and the IshikawaCoastJapanrdquo Journal of Coastal Research Special Issue vol 56 pp1701ndash1705 2009

[5] K Tazaki ldquoHeavy oil spilled from Russian tanker ldquoNakhodkardquoin 1997 towards eco-responsibility earth senserdquo in 21st Cen-tury COE Kanazawa University Kanazawa University PressKanazawa Japan 2003

[6] S K Chaerun K Tazaki R Asada and K Kogure ldquoBioreme-diation of coastal areas 5 years after the Nakhodka oil spill inthe Sea of Japan Isolation and characterization of hydrocarbon-degrading bacteriardquo Environment International vol 30 no 7pp 911ndash922 2004

[7] T Nakamura ldquoIdentification and prioritisation of marineenvironmental problems in the Sea of Japan and strategicplanning for addressing themrdquo in Proceedings of the 1stMeeting of Experts and National Focal Points (NFPs) on the

ISRN Oceanography 11

Development of the Northwest Pacific Action Plan (NOWPAP)pp 28ndash31 Centre for International Projects and the PacificOceanological Institute Vladivostok Russia 2004 httpwwwunepchregionalseaspubsprofilesnowpapdoc

[8] K Hayakawa M Nomura T Nakagawa et al ldquoDamage to andrecovery of coastlines pollutedwithC-heavy oil spilled from theNakhodkardquoWater Research vol 40 no 5 pp 981ndash989 2006

[9] A C Redfield B H Ketchum and F A Richards ldquoTheinfluence of organism on the composition of seawaterrdquo In theSea vol 2 pp 26ndash77 1963

[10] T R Parsons Y Maita and C M Lalli A Manual of Chemicaland Biological Methods for Seawater Analysis Pergamon PressNew York NY USA 1984

[11] SWNixon ldquoCoastal eutrophication a definition social causesand future concernsrdquo Ophelia vol 41 pp 199ndash220 1995

[12] H W Paerl ldquoCoastal eutrophication and harmful algal bloomsImportance of atmospheric deposition and groundwater asrsquonewrsquo nitrogen and other nutrient sourcesrdquo Limnology andOceanography vol 42 no 5 pp 1154ndash1165 1998

[13] C J Gobler and G E Boneillo ldquoImpacts of anthropogenicallyinfluenced groundwater seepage on water chemistry and phy-toplankton dynamics within a coastal marine systemrdquo MarineEcology Progress Series vol 255 pp 101ndash114 2003

[14] K R Kim K Kim D J Kang et al ldquoThe East Sea (Japan Sea) inchange a story of dissolved oxygenrdquoMarine Technology SocietyJournal vol 33 no 1 pp 15ndash22 1999

[15] K Keller R D Slater M Bender and R M Key ldquoPossiblebiological or physical explanations for decadal scale trends inNorth Pacific nutrient concentrations and oxygen utilizationrdquoDeep-Sea Research Part 2 vol 49 no 1ndash3 pp 345ndash362 2002

[16] T Ono T Midorikawa Y W Watanabe K Tadokoro and TSaino ldquoTemporal increases of phosphate and apparent oxygenutilization in the subsurface water of western subarctic Pacificfrom 1968 to 1998rdquo Geophysical Research Letters vol 28 no 17pp 3285ndash3288 2001

[17] YWWatanabe TOnoA Shimamoto T SugimotoMWakitaand SWatanabe ldquoProbability of reduction in the formation rateof the subsurfacewater in theNorth Pacific during the 1980s and1990srdquo Geophysical Research Letters vol 28 no 17 pp 3289ndash3292 2001

[18] S Emerson S Mecking and J Abell ldquoThe biological pumpin subtropical North Pacific Ocean nutrient sources Redfieldratios and recent changesrdquo Global Biogeochemical Cycles vol15 no 3 pp 535ndash554 2001

[19] G Shaffer O Leth O Ulloa et al ldquoWarming and circula-tion change in the eastern South Pacific Oceanrdquo GeophysicalResearch Letters vol 27 no 9 pp 1247ndash1250 2000

[20] N L Bindoff and T J McDougall ldquoDecadal changes along anIndian Ocean section at 32∘S and their interpretationrdquo Journalof Physical Oceanography vol 30 no 6 pp 1207ndash1222 2000

[21] N L Bindoff J Willebrand V Artale et al ldquoObservationsoceanic climate change and sea levelrdquo in Climate Change 2007The Physical Science Basis S Solomon D Qin M Manninget al Eds Contribution of Working Group 1 to the 4thAssessment Report of the Intergovernmental Panel on ClimateChange Cambridge University Press Cambridge UK 2007

[22] R R Stickney Encyclopedia of Aquaculture JohnWiley amp SonsNew York NY USA 2000

[23] P B Moyle and J J Cech Fishes An Introduction to IchthyologyPrentice Hall Englewood Cliffs NJ USA 5th edition 2004

[24] J P Gattuso and R W Buddemeier ldquoCalcification and CO2

rdquoNature vol 407 no 6802 pp 311ndash313 2000

[25] C D G Harley A R Hughes K M Hultgren et al ldquoTheimpacts of climate change in coastal marine systemsrdquo EcologyLetters vol 9 no 2 pp 228ndash241 2006

[26] E A Ainsworth and S P Long ldquoWhat have we learned from15 years of free-air CO

2

enrichment (FACE) A meta-analyticreview of the responses of photosynthesis canopy propertiesand plant production to rising CO

2

rdquo New Phytologist vol 165no 2 pp 351ndash372 2005

[27] Y Shirayama andHThornton ldquoEffect of increased atmosphericCO2

on shallow water marine benthosrdquo Journal of GeophysicalResearch C vol 110 no 9 Article ID C09S08 pp 1ndash7 2005

[28] World Health Organization Coastal and Fresh Waters vol 1of Guidelines for safe Recreational Water Environments WHO2003

[29] G P Harris ldquoBiogeochemistry of nitrogen and phosphorusin Australian catchments rivers and estuaries effects of landuse and flow regulation and comparisons with global patternsrdquoMarine and Freshwater Research vol 52 no 1 pp 139ndash149 2001

[30] ANZECCARMCANZ ldquoAustralian and New Zealand Guide-lines for Fresh and Marine Water Qualityrdquo 2000 httpwwweagovauwaterqualitynwqmsquality

[31] V N De Jonge M Elliott and E Orive ldquoCauses historicaldevelopment effects and future challenges of a common envi-ronmental problem eutrophicationrdquo Hydrobiologia vol 475-476 no 1 pp 1ndash19 2002

[32] C A Almeida S Quintar P Gonzalez and M A MallealdquoInfluence of urbanization and tourist activities on the waterquality of the Potrero de los Funes River (San Luis-Argentina)rdquoEnvironmental Monitoring and Assessment vol 133 no 1ndash3 pp459ndash465 2007

[33] S Tanaka S Satoh S Kawagishi T Ishikawa Y Yamamotoand G Asano ldquoSand transport mechanism in Ishikawa coastrdquoProceedings of Coastal Engineering vol 44 pp 661ndash665 1997(Japanese)

[34] M Yuhi ldquoImpact of anthropogenic modifications of a riverbasin on neighboring coasts a case studyrdquo Journal of WaterwayPort Coastal and Ocean Engineering vol 134 no 6 pp 336ndash344 2008

[35] UNEP ldquoNational reports on marine pollution preparednessand response in the Northwest Pacific Regionrdquo NOWPAPPublication no 4 UNEPRegional SeasIMO 1998

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

Geological ResearchJournal of

Volume 2013

ISRN Paleontology


Geochemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Geophysics


Journal ofPetroleum Engineering


Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

OceanographyInternational Journal of


ISRN Oceanography


EarthquakesJournal of


Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal of

Geophysics

ISRN Atmospheric Sciences



MineralogyInternational Journal of

ISRN Meteorology


Meteorology


Advances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Mining


Journal of

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Geology


Atmospheric SciencesInternational Journal of


2 ISRN Oceanography

excessive groundwater extractions [5ndash8] In this study wefound that in the last three decades there were significantspatial and temporal changes in some water quality parame-ters Therefore it is expected that with the significant spatialdifferences in land use and human impact along the coastcoastal water quality may continue to degrade in the absenceof effective positive policy drive

Along the Ishikawa coast patches of documented fieldwater-quality monitoring data date back to 1974 Here weevaluate the degree of water quality change on the Ishikawacoast from documented in situ water quality measurementsdata (DO COD pH temperature T-N and T-P) providedby the EnvironmentDepartment IshikawaPrefecturalOfficeJapan (Ishikawa Prefecture Annual Report of the WaterQuality from Underground Water and Public Water) ourfield observations and interviews

Lastly the aims of this study were to analyze anddocument trends of change in some coastal water qualityparameters using ground-based data from three contrastingcoastal systems of Ishikawa coast and to deduce some naturaland anthropogenic drivers of change From the point of viewof water quality it hopes to explore vulnerable areas on thecoast and to document implication of changes on the long-term sustainability of Ishikawa coastal ecosystems

2 Study Area Description

The present study area Ishikawa coast is located on the mid-dle north of Japan and lies between 36∘171015840N to 37∘521015840N lat-itude and between 136∘141015840E to 137∘211015840E longitude (Figure 1)The coastline has a general NE-SW orientation [4] and thecoastline has sim581 km alongshore stretch with significantlydifferent physiographies and topographies from northern(Noto) to southern (Kaga) districtThis study area is classifiedinto three coastal compartments based on the significantcontrasting physiographic (physical characteristics) changesalong the coastline and the need to explore the driversand mechanisms of change The first coastal compartmentmdashKanazawa area (hereafter KNA)mdashis an exposed bay notedas a large littoral cell stretching approximately 75 km alongthe Japan Sea Coast [4] on the southern coast (between southKaga and Hakui) and features sandy beaches shorelines andstrong sea waves of the Sea of Japan The second coastalcompartment is the Noto area (hereafter NTA) an exposedbay located on the northern coast (between Shika and Notoend of Suzu) dotted with sheer cliffs and unusual rockformations and also characterized by high and intense seawaves of the Sea of Japan This coastal compartment (NTA)is acclaimed one of the largest fisheries development ports inJapan The Nanao area (hereafter NNA) is the third coastalcompartment (from Noto town down to Nanao) a calmercoast facing Nanao Bay blessed with a fine harbor protectedagainst strong south andwest winds and has a thriving fisherywith an average annual fish catch of approximately 1000metric tons in recent years It is an enclosed bay and featuresboth sandy beaches and rocky shorelines

Generally Ishikawarsquos climate is strongly influenced by theTsushima warm water current and winter wind causing awide variety of seasonal environments It can be described as

being humid wet and hot in summer and rainy and receivinglots of snow in winter

3 Materials and Methods

This study is based on decadal and comparative analysisof existing records and in situ measurements data of somewater quality parameters on the Ishikawa coast obtainedfrom the Water Quality Monitoring Unit EnvironmentDepartment Ishikawa Prefectural Office Japan and fromfield observations and interviews Consistent water qualitydata was available from 33 stations designatedmdashKNA (20)NTA (6) andNNA (7)mdashand sampled (0-1mdepth) along thecoastal zone (lt5 km from shoreline) of Ishikawa between 1974and 2009 Nutrient data were available only at five stationscharacterized by strong human influence riverine dischargeand enclosed coastal ecosystems at KNA (2 stations) andNNA (3 stations) coastal compartments Here we analyzedfor trends and possible drivers of change in some waterquality parameters dissolved oxygen (DO) chemical oxygendemand (COD) an environmental quality standard (EQS)for the conservation of the living environment and typicalwater quality indicators for organic contaminant hydrogenion concentration (pH) total nitrogen (T-N) and totalphosphate (T-P) on a five-year interval between 1984 and2009 at the three coastal compartments (KNA NTA andNNA)

31 Sampling and Analysis Water samples were collectedannually with monthly and station sample size (119899) range10ndash12 and 30ndash33 respectively Temperature pH and DOwere measured in situ using calibrated portable meterswhile water samples were analyzed in the laboratory forCOD (colorimetric) T-N and T-P Nutrient concentrationswere measured according to [10] between 1980s and early90s immediately after sampling and from mid-1990s to2009 nutrient concentrations were measured with Bran andLuebbe Auto Analyser Traacs 800 after storage at minus20∘C

32 Statistical Analysis Variations in surface water qualityparameters (DO COD pH temperature T-N and T-P) werecompared for the three coastal compartments (KNA NTAand NNA) across three decades (between 1984 and 2009)using a two-way analysis of variance (ANOVA) whereasthe Duncan multiple range test was used for separation ofmeans Intercorrelation of variables was investigated usingthe Pearson product-moment correlations coefficient

4 Results

41 Spatial and Temporal Variation in Environmental Vari-ables Mean annual distribution of rainfall and atmospherictemperature between 1930 and 2010 across the three coastalcompartments (KNA NTA and NNA) on Ishikawa coastare presented in Figures 2(a) and 2(b) Mean annual rainfallvalues over the last eight decades showed highly significant(119875lt0001) temporal and spatial variation across the Ishikawaprefecture (KNA NTA and NNA)Themean annual rainfall

ISRN Oceanography 3

NNANTA


(km)

N


1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 20200

500

1000

1500

2000

2500

3000

3500

Mea

n an

nual

rain

fall

(mm

)

Period (yr)

KNANTANNA

(a)

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

KNA

NNA

0

4

8

12

16

20

Mea

n an

nual

tem

pera

ture

(∘C)

Period (yr)

NTA

(b)





4 ISRN Oceanography

0

1

2

3

4

5

6

7

8

9

10

11D

issol

ved

oxyg

en D

O (m

gL)

1984 1989 1994 1999 2004 2009Period (yr)

(a)

75

76

77

78

79

8

81

82

83

84

85

86

Hyd

roge

n io

n co

ncen

trat

ion

(pH

)

1984 1989 1994 1999 2004 2009Period (yr)

(b)

KNANTANNA

002040608

112141618

2222426

1984 1989 1994 1999 2004 2009

Chem

ical

oxy

gen

dem

and

CO

D (m

gL)

Period (yr)

(c)






ISRN Oceanography 5

























6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)


0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA





5 Discussion


ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




ISRN Oceanography 3

NNANTA


(km)

N


1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 20200

500

1000

1500

2000

2500

3000

3500

Mea

n an

nual

rain

fall

(mm

)

Period (yr)

KNANTANNA

(a)

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

KNA

NNA

0

4

8

12

16

20

Mea

n an

nual

tem

pera

ture

(∘C)

Period (yr)

NTA

(b)





4 ISRN Oceanography

0

1

2

3

4

5

6

7

8

9

10

11D

issol

ved

oxyg

en D

O (m

gL)

1984 1989 1994 1999 2004 2009Period (yr)

(a)

75

76

77

78

79

8

81

82

83

84

85

86

Hyd

roge

n io

n co

ncen

trat

ion

(pH

)

1984 1989 1994 1999 2004 2009Period (yr)

(b)

KNANTANNA

002040608

112141618

2222426

1984 1989 1994 1999 2004 2009

Chem

ical

oxy

gen

dem

and

CO

D (m

gL)

Period (yr)

(c)






ISRN Oceanography 5

























6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)


0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA





5 Discussion


ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




4 ISRN Oceanography

0

1

2

3

4

5

6

7

8

9

10

11D

issol

ved

oxyg

en D

O (m

gL)

1984 1989 1994 1999 2004 2009Period (yr)

(a)

75

76

77

78

79

8

81

82

83

84

85

86

Hyd

roge

n io

n co

ncen

trat

ion

(pH

)

1984 1989 1994 1999 2004 2009Period (yr)

(b)

KNANTANNA

002040608

112141618

2222426

1984 1989 1994 1999 2004 2009

Chem

ical

oxy

gen

dem

and

CO

D (m

gL)

Period (yr)

(c)






ISRN Oceanography 5

























6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)


0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA





5 Discussion


ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




ISRN Oceanography 5

























6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)


0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA





5 Discussion


ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




6 ISRN Oceanography

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608Total nitrogen

NP

119910 = 00468119909 + 00335

1198772 = 0249

(a)

Total nitrogen

NP

119910 = 01078119909 + 00023

1198772 = 00829

0004008012016

02024028032036

04044048

Tota

l pho

spha

te

0 02 04 06 121 14 1608

(b)


0

5

10

15

20

25

30

35

40

1984 1989 1994 1999 2004 2009

Ann

ual N

P ra

tio

Period (yr)

NNAKNA





5 Discussion


ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




ISRN Oceanography 7











2in the upper ocean



2[14ndash20]

















8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




8 ISRN Oceanography











ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




ISRN Oceanography 9

0

500

1000

1500

2000

2500

3000

1965 1970 1975 1980 1985 1990 1995 2000 2005

Num

ber o

f con

firm

ed ca

ses

Years








6 Conclusion




02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology





02468

10

KNA

NTA

NNA

JapanEQS

(a)

8

81

8283

84

85KNA

NTA

NNA

JapanEQS

(b)

0

05

1

15

2KNA

NTA

NNA

JapanEQS

(c)


Acknowledgments


References






























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology


























2


2














Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology






Volume 2013


Volume 2013

ISRN Paleontology


Geochemistry


Journal of

ISRN Geophysics







ISRN Oceanography






Geophysics





ISRN Meteorology


Meteorology


Advances in



Mining


Journal of


ISRN Geology




Regional Analysis on Decadal Variation in Aspects of Water Quality in Three Contrasting Coastal...

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