The Botanical Importance Rating of the Estuaries in Former Ciskei / Transkei B.M
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I:' iiiJr ijjjifJ1J';;iiI t2lnicaIIi)! ,UJ! 13MC(J11(Jy, JI3AGandr.(J ai- !WaterResearch CommissionIT 160/01 THE BOTANICAL IMPORTANCEFORMER CISKEI RATING / TRANSKEI OF THE ESTUARIES IN B.M. COLLOTY, J.B. ADAMS AND OC. BATE FINAL REPORT TO THE WATER RESEARCHBY THE COMMISSION UNIVERSITYDEPARTMENT OF PORT OF BOTANY ELIZABETH WRC REPORT NO. TT 160/01 Obtainable from: Water0001PretoriaPO Box Research 824 Commission The publicationrating of Estuaries of this report in former emanates Ciskei from and aTranskei project (WRCentitled: Project The Botanical No K5/81 Importance 2) This report has been reviewed by the WaterDISCLAIMER Research Commission (WRC) and approved for publication.the WRC, norApproval does mentiondoes not of signify traderecommendation thatnames the or contents commercial for necessarily use. products reflect constitute the views ensoresement and policies or of PrintedISBN in1 the86845 Republic 790 of 7South Africa aboveThe average Jujura Estuary, depth of one 2.8 ofm, several remained unique open estuaries for extensive observed periods in thisand study.was colonized This small by estuaryZostera had capensis. an EXECUTIVE SUMMARY ThereBACKGROUND are an increasing AND number MOTIVATION of people FOR utilising THE RESEARCHthe South African coastline. This is creating a need to assessmentsmanagementevaluate estuary havemust and becometake coastal place. necessary resources Management toand summarise to tools identify such and sensitive as express importance areas scientific where rating information. carefulsystems planning and The state botanicaland or condition theProjectimportance area (Adams covered rating et by system al. estuarine 1996). is one That plants, such project theirmethod rated condition, and the was botanical the developed number importance of in plant a previous ofcommunity 33 Cape Water typesestuaries Research and accordingthe Commission to theassociationincluded botanical in thebetween importance survey. the This plantsrating project furtherand fundedthe and estuary. wasby the applied The Water report to Research the suggested former Commission Ciskei that theand remainder Transkeifor three years,regionsof the coastlinedeveloped of the be EasternTERMINOLOGY Cape Province. communitystudyBotanical botanical importance type importance rarity. refers Functional is to the the sumimportance contribution of functional is of the the importance, area plants covered to the species byconservation the richness, different status communityplant ofcommunity an estuary.richness types In and this Themultipliedintertidal term salt plantby anmarsh community average fail to productivìty adheretype is usedto the value instead definition for the of plantofdifferent a true communities community,community because types.i.e. a clearly botanical defined groups assemblagesuch as of plantsSTUDY and/or APPROACH animals distinguishable from other such assemblages. availableBotanicalOnce-off forsurveys eachmeasurement estuarywere conducted includes: of salinity, in 92temperature, estuaries found depth, in secchi the former depth, Transkei water column and Ciskei chlorophyll-a region. Data and AreanitrateNumber covered concentrations. of different by the plant different community plant community types and types. species composition. iv These data were then used to determine: estuariesrarityBotanical and andfunctional importance for 87 importance.other of Southan estuary TheAfrican botanicalthat estuaries. includes importance speciesThe distribution scoresand community were of plants calculated richness, in the forCiskei plant all Ciskei I communityTranskei I Transkei estuaries type changein relationThe habitat in toarea physical integrity covered factors or by health the was different of described. an estuary plant community can be determined types is measured using the fromfunctional past andimportance present scores.aerial The thepresentphotographs. habitat functional integrity The functionalimportance score is calculated importance scores. Theas is the applicationthen deviation calculated of from habitat using natural, integritythe earliesti.e. loowas lessand tested themost ondifference recent 16 Northern area in past values and and SouthPROJECTPondoland African estuariesOBJECTIVES estuaries. and the (as Swartkops specified Estuary.in the original Overall contract) habitat integrìty scores were calculated for 129 resultThe extent of the to project which findingsthe project are objectivesprovided in were boxes. met is outlined below. Recommendations or actions as a Ninety-two1. estuariesformerTo extend Ciskei in thethe and botanicalCiskei Transkei I Transkei importance region. regions rating were system surveyed of Cape and estuaries the botanical to include importance estuaries calculated. of the includingThe1996). revised In Lakeaddition importance St Lucia. to this, ratingThe Ms surveyT was Riddin also of (M.Sc.,Lake applied St UPE)Lucia to the completedwas 33 estuariesdone insurveys collaboration studied of 6by northern Ms with Coetzee Mr. KwaZulu-Natal R Taylor (Adams (KwaZulu- et estuariesal. areainNatal the and NatureDurban the revisedConservation Metropolitan importance Services).area. ratingMr. D Ms wasWalker S Pillayalso (Ph.D. applied (CSIR, student, to Durban) those UPE) estuaries. has surveyed provided All estuariesthe information information in the on wasEastthe estuaries collatedLondon in theainformation database project was constructedon allsuccessfully South inAfrican Microsoft met estuariesand Access. also extendedwith This sufficient database by including information is a finalestuaries toproduct rate outside 179 from estuaries. ofthis the project study This andarea. objectiveincludes of forThatRecommendatíon: Estuarine the botanical Research importance and Management) database is madewebsites. available on the WRC and CERM (Consortium V 2. system.To incorporate a fifth plant community type, i.e. mangroves into the botanical importance rating intertidalrevisedThis objective importance benthic was microalgae, metrating and system. extended macroalgae, Nine because estuarine submerged mangroves, plant macrophytes, community microalgae types intertidal and are swamp now salt included;marsh, forest supratidalwere phytoplankton, included salt in the communityformulamarsh, reeds(Coetzee type and richness etsedges, al. 1996, and mangroves 1997)plant community are and the swampinclusion type forest.rarity. of functional Other refinements importance, to species the original richness, importance plant rating estuariesThe revised within formula both can the nowstudy be region applied and to otherany South estuaries African that estuary had information and, in this available. study, was The used revised to rate the Waterestuarybotanical Act importance importance (Act 36 of and1998). rating health. has Thesealso been methods used inhave the beenResource developed Directed to allowMeasures implementation for estuaries of to the determine National IDeveIcpmin theand ontBatanloal national protocol c,f SeotiQnbotanical rating lmpartanoefor future 4 of importance estuaries use ratine BotanicalCiakeiSectionestuaries and importance Tra 6 nakei of The influenceCiskeionHabitat plant andof the Transkei Integritydistribution phyaica estuaries I inenvironment The use of a habitat Developmentintegrity index Sectionof Habitat 7.1 IntegrityEastern Index Pondoland estuaries developmentto determine (Sectionon the theSwartkops 7.2) affect of estuary National(Section habitat 7.3) integrity Distribution(Sectionof estuaries 7.4) and state of developedFlow chart in depicting this study. the components of the botanical importancemangroves alongSection rating the 8Transkei and habitat coast integrity index vi To provide baseline data on plant structure and distribution in relation to freshwater input in a qualityData from at the theregion time field of wheresurveys sampling, little have datapast been existedand summarised present previously. area in covered the botanical by the importance different plant database. community This types,includes water moreOrdinationcomments saline onwas to the freshwater used impacts to relate plantand theactivities community distribution in the types ofvicinity the moving plants of the from to estuary physical south and to variables. north photographs in the There study of was the region. estuaries.a transition This was from a theresult morphology of the Totransition translate of the inestuaries. scientificbiogeographic information regions on coupled the freshwater to an increase requirements in mean of annualmangroves rainfall into together management with theSalinity literature. and toolsinundation For toexample, be usedtolerance it in is decision known ranges that support for mangroves the differentsystems. can South survive African permanently mangrove inundated species was for obtainedonly 4 - 5 from sectionitmonths indicates ofbefore the the report. permissibledie-back. This period type of of mouth information closure. is used This ininformation estuarine isfreshwater summarised requirement in the literature studies review because distributionthanThe studyreduced identified of freshwatermangroves. that theinput. current Section threat 7 focuses to mangroves on this in aspect the study and areacompares was uncontrolled the past and harvesting present rather SUMMARYThe botanical OF importanceFINDINGS of South African estuaries determineSixtybecause five theypercent their had botanical of high the functionalestuaries importance. foundimportance The in StSouth Lucia, scores, Africa Mngazana, community