S.Pillay1;3,Dr.A.J.Smit2,DrD.Robertson-Andersson1;3

1UKZN2UWC

3MACELab

Introduc)on

MainAimTheaimofthisstudywastoinvestigatethelevelandextentofNpollutiontothesouthcoastofKZN

Objec)vesThespecificobjectiveswere:

�  (1)Todetermineifeachestuarychosenforthisstudyiseutrophicandcomparisonsmadewiththecurrentknownhealthstatus

�  (2)Todeterminetheeffectofseasononnitrogenpollutioninrockyshoresduringtheclosedandopenphaseoftheestuary

�  (3)Todetermineifthelevelofnitrogenpollutionchangeswithincreasingdistanceawayfromtheestuary.

HypothesesItwashypothesisedthat:�  (1)ThereisadifferenceinNpollutionamongthethreesites(Hibberdene,MargateandPortEdward).

�  (2)Rockyshorehabitatsaresupplementedbynutrientsfromestuarinesources

Studydesign

Choosingestuaries

Health state of estuary Description

Excellent Estuaries with high water quality, level of habitat integrity are high, high diversity and high provision of goods and services.

Good Estuaries with most of the core estuarine habitat and estuarine support habitats still present, good water quality, diversity of habitats and species and estuarine processes in place.

Fair Estuaries with core estuarine habitat intact, some estuarine support habitats, impacted water quality and some loss of diversity and key estuarine process in place.

Poor Estuaries with impacted core estuarine habitat. Substantially reduced or no estuarine support habitats, polluted water, substantial loss of diversity and/or abundance and key estuarine processes impaired.

Highly degraded Estuaries which have had major impacts on core estuarine habitats through infilling, canalisation and pollution, substantially reduced or no estuarine support habitats and major loss of key estuarine processes.

Table1.Rankingofesturinestatebasedonfunctionngandhealthofthesystem(adaptedfromForbes&Demetriades(2008))

Mhlungwa(Hibberdene)

Kongweni(Margate)

Mtamvuna(PortEdward)

Studysites

Figure 1. Map of sites chosen for study

HibberdeneHibberdene(MhlungwaEstuary)

Margate(KongweniEstuarywithWWTP)

PortEdward(UmtamvunaEstuary)

Hibberdene(MhlungwaEstuary)

Margate(KongweniEstuarywithWWTP)

PortEdward(UmtamvunaEstuary)

Sampling

Mouth:POMDINδ15N(POM)Chla

100m

200m

1000m

2000m

δ15NofMacroalgae

Figure 2. sampling plan for each site

600m

Nutrientanalysis�  FilteredsampleswereanalysedfornitrateandphosphateusingSKALARSAN++nutrientanalyser

POM�  Filtratecollectedonpre-combustedGFFfilterswereusedforPOM

�  Isotopeanalysis

Macroalgae�  JaniaintermediaandHypneaspicifera

www.mpcer.nau.eduTakenby:ShivaneePillay

Sta)s)calanalyses� AnalysisofCovariance(ANCOVA).� ANOVA

ResultsEstuary

Figure2LevelofnutrientpollutionineachoftheestuariesinHibberdene(Mhlungwa),Margate(Kongweni)andPortEdward(Umtamvuna)

RockyShores

Figure5.2LevelofnitrogenpollutiondistributedacrossstationsinHibberdene(Mhlungwa),Margate(Kongweni)andPortEdward(Umtamvuna)

Overalloutcomesandrecommenda)ons�  Nitrogenpollutionisevidentamongthesitesconcerned�  Itissuggestedthatboththeestuaryandrockyshorehabitatbemonitoredtoelucidateotherfactorsnotconsideredhere.

�  TheconditionofsiteschosenforthisstudyclearlyindicateaneedformitigationofnutrientpollutioninestuariesandagreaterneedfordevelopmentofWWTWalongthecoastofKZN.

�  AsurveyoftheKZNcoastlinewillgiveanindicationofthosesimilarlyimpactedandinneedofmitigation

Thankyou

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