I :' r ijjj iiiJ ifJ1J';;iiI t2lnicaII i)! ,UJ! 13M JI3AGand r.C(J11(Jy,(J ai - !Water Research Commission IT 160/01 THE BOTANICAL IMPORTANCE RATING OF THE ESTUARIES IN FORMER CISKEI / TRANSKEI B.M. COLLOTY, J.B. ADAMS AND OC. BATE FINAL REPORT TO THE WATER RESEARCH COMMISSION BY THE UNIVERSITY OF PORT ELIZABETH DEPARTMENT OF BOTANY WRC REPORT NO. TT 160/01 Obtainable from: Water0001PretoriaPO Box Research 824 Commission The publication of this report emanates from a project entitled:rating Theof Estuaries Botanical in Importanceformer Ciskei and Transkei (WRC Project No K5/81 2) This report has been reviewed by the Water Research Commission (WRC) and approved for DISCLAIMER publication. Approvalthe WRC, does nor not does signify mention that the of contentstrade names necessarily or commercial reflect theproducts views constitute and policies ensoresement of or recommendation for use.

PrintedISBN in1 the86845 Republic 790 of 7South Africa above average depth of 2.8 m, remainedThe Jujura open Estuary, for extensive one of several periods unique and was estuaries colonized observed by Zostera in this capensis. study. This small estuary had an EXECUTIVE SUMMARY There are an increasing numberBACKGROUND of people utilising AND the MOTIVATION South African FORcoastline. THE RESEARCHThis 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 covered (Adams rating by et system estuarineal. 1996). is oneplants, That such project their method condition, rated and the was thebotanical numberdeveloped importance of plant in a previouscommunity of 33 Cape Water types estuaries Research and the according Commission to theassociationincluded botanical in between importancethe survey. the plantsratingThis project furtherand the funded and estuary. was by applied theThe Water report to the Research suggested former CiskeiCommission that theand remainder Transkei for three of years, the coastline developed be regions of the Eastern Cape Province. TERMINOLOGY 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 multipliedTheintertidal term plantby salt an communitymarsh average fail productivìty to type adhere is used to value the instead definition for the of plantdifferent of a communities true community community, because types. i.e. a botanical clearly defined groups assemblage of such as plants and/or animals distinguishableSTUDY fromAPPROACH other such assemblages. availableBotanical forsurveys each estuarywere conducted includes: in 92Once-off estuaries measurement found in the of former salinity, Transkei temperature, and Ciskei depth, region. secchi Data depth, water column chlorophyll-a and AreanitrateNumber covered concentrations. of different by the different plant community plant community types and types. species composition. iv These data were then used to determine: estuariesrarity and andfunctional for 87 importance.other SouthBotanical TheAfrican importance botanical estuaries. importance of anThe estuary distribution scores that wereincludes of plants calculated species in the forCiskei and all community Ciskei I Transkei I Transkei richness,estuaries plant community type inchange relation in toarea physical covered factors byThe the washabitat different described. integrity plant communityor health of types an estuary is measured can be fromdetermined past and using present the functionalaerial importance scores. The thepresentphotographs. habitat functional integrity The score functionalimportance is calculated importance scores. as The the is applicationthen deviation calculated from of habitat natural,using integritythe i.e. earliest loo was less and tested the most difference on recent 16 Northern inarea past values and and SouthPondolandPROJECT African estuariesOBJECTIVESestuaries. 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-two estuaries in the Ciskei I Transkei regions were surveyed and the botanical1. importance calculated. formerTo extend Ciskei the andbotanical Transkei importance region. rating system of Cape estuaries to include estuaries of the includingThe1996). revised InLake additionimportance St Lucia. to this, ratingThe Ms survey was T Riddin also of Lake applied (M.Sc., St Lucia to UPE) the was 33completed estuariesdone in surveyscollaboration studied of by 6 Ms northernwith Coetzee Mr. RKwaZulu-Natal Taylor (Adams (KwaZulu- et al. estuaries areainNatal theand NatureDurban the revised Conservation Metropolitan importance Services).area. rating Mr. Dwas Ms Walker Salso Pillay applied(Ph.D. (CSIR, student,to thoseDurban) UPE)estuaries. has surveyed provided All the estuaries information information in the on was Eastthe estuaries London collated in thea databaseinformation project was constructed on successfully all South in MicrosoftAfrican met and estuaries Access. also extended with This sufficient database by including information is a finalestuaries product to rate outside from179 estuaries.ofthis the project study This andarea. objective of includes 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(Act importance 36 of 1998). and rating health. has Thesealso been methods used inhave the beenResource developed Directed to allowMeasures implementation for estuaries of to the determine National IDeveIcpm ont c,f botanical importance ratine in the national rating of estuariesand protocol for futureBatanloal use lmpartanoe SeotiQn 4 Botanical importanceCiakei and ofTra nakei Sectionestuaries 6 The influence of the phyaica I environment Ciskei and Transkei estuaries on plant distribution inHabitat Integrity The use of a habitat integrity index to determine the affect of Development of Habitat Integrity Index Section 7.1 Eastern Pondoland estuaries (Section 7.3) development on the Swartkops estuary (Section 7.2) National habitat integrity of estuaries mangroves along the Transkei coast Distribution(Section 7.4) and state of developedFlow chart in depicting this study. the components of the botanical importance rating and habitat integrity index Section 8 vi To provide baseline data on plant structure and distribution in relation to freshwater input in a qualityData from at the the time field of surveys sampling, have past been and summarised present area in covered the botanical by the importance different plant database. community This types,includes water region where little data existed previously. 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 transition of the estuaries. in biogeographic regions coupled to an increase in mean annual rainfall together with To translate scientific information on the freshwater requirements of mangroves into management theSalinity literature. and Forinundation example, tolerance it is known ranges that formangroves the different can South survive African permanently mangrove inundated species forwas only obtained 4 - 5 from tools to be used in decision support systems. 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 FINDINGS importance of South African estuaries determineSixtybecause five percent their they botanical had of thehigh estuaries importance.functional found importance The in StSouth Lucia, scores, Africa Mngazana, (179 community estuaries) Nxaxo richness and had Mbashe information and community Estuaries that could rarity.were be importantSixteen used to estuarieshighestpercent scores.of with the lowTranskei The functional combination estuaries importance ofand the 44% components scores, of Ciskei but with estuariesin the rich botanical or were rare included plantimportance community in the rating 20 typesestuaries allowed to have thewith smallhigh the weighting,extensiveimportance submergedas theyscores, only e.g.macrophyte occur the in Kabeljous, 39 andSouth macroalgal AfricanSeekoei estuaries. andareas. Uilkraals Submerged Estuaries. macrophytes These three have estuaries a high rarity contained vu Note must be taken of the importanceRecommendation: of the Nxaxo Estuary. The state of the estuary is currently The influence of the physical environment on the distribution ofunder estuarine threat plants from proposed in the former dune miningCiskei at Wavecrest. andtotalFor Transkei54 the plant first species timeregion. a comprehensive were found in the botanical 92 estuaries survey surveyed. has taken These place plantsin the Ciskeicould beand divided Transkei into estuaries. the In species),followingOrdination fivemacroalgae techniques plant community (3were species) used types; toand describe reeds swamp and theforest sedges relationships (4 species). (23 species), between salt species marsh distribution(20 species), and mangroves physical (4 usingofvariables estuary). multivariate (average Estuaries analysis. nitrate could concentration, Thesebe divided were; into light 7 broadattenuation, classes salinity, based temperature, on the spatial water separation column of depth plant andspecies size thepermanently Mngazana open Estuary estuaries which with is separated mangrovesextensive from salt and marshesthe salt other marsh occurringpermanently south ofsouth the open ofMngazana the estuaries Great Estuary, Keibecause River itEstuary, has largepermanentlymangroves, temporarily salt open marsh open/closed estuaries and swamp with estuaries mangroves forest, with salt and marsh swamp and forest macroalgae north of theoccurring Mngazana south Estuary, of the Great Kei EstuarysmallRiver Estuary,temporarily and open/closed estuaries with only reeds and sedges occurring north of the Great Kei River The Mngazana Estuary was classified onMngazanasmall its own temporarily due Estuary. to its open/closed unique geomorphology estuaries with and reeds, floodplain sedges features. and swamp forest occurring north of the lt northtypes.has the in There thirdthe study largestwas aregion. transitionmangrove This from wasarea morea in result the saline country of the to transition freshwaterand contained in plant biogeographic 8 communityout of the regions9 typespossible moving (warm plant temperatefrom community south to to hightransition,subtropical) botanical in coupledturn, importance caused to an an scoresincrease increase for in estuaries inmean species annual in richnessthis rainfall region. and together habitat with diversity the morphology and this was of reflectedthe estuaries. in the The v'il Thatprotection.Recommendation: the national importance of Mngazana Estuary is recognised and the estuary receives TheHabitat habitat integrity integrity ofor Southhealth ofAfrican an estuary estuaries can be determined using the change in the botanical functional allyears, importanceSouth as Africanwell scoreas estuariesfor over16 Pondoland time. (129) Habitat that (northern had integrity available Transkei) was information determined estuaries. and for Habitat comparedthe Swartkops integrity on a scoresEstuarynational were overbasis. calculateda period of for 60 SwartkopsHuman impacts Estuary have reduced the habitat integrity of the Swartkops Estuary by 50%. Industrial and residential occurred.Supratidaldevelopments However, salt includingmarsh only was roads 5 estimated ha andremains bridges to (acover reduction have an encroached area of of88%). approximately intoThe areas intertidal that40 ha saltwere before marsh previously any was development reduced salt marsh. in cover common¡tfrom ¡s only 215 scenarioperiodicallyha to 165 in ha ainundated number(a reduction of and, South of with 23%). African suitable Supratidal estuaries. engineering, salt marsh is more has beenprone most to development. affected probably This is because a verticalRecommendation:Habitat aerial integrity photographs can effectively of an estuary be used (preferred as a long-term scale 1:monitoring 5 000). tool. All that is required are A regionalPondolandplant community assessment estuaries types of was the Pondolandsmall, these estuaries estuaries showed are nationally that although important the asarea they covered have been by the the estuarine least trees.suchimpacted as the overmangrove time i.e. fern they and have fringe high mangrove habitat integritystands i.e. scores. the mangroves These estuaries occur asalso a havedouble unique or single species row of ix Recommendation: EstuaryManagementPondoland in southern estuaries for a marine KwaZulu-Natal must protectedreceive amust areahigh be fromprotection supported. Mntafufu status, Estuary the proposal north of Portby Marine St Johns and to Coastal Mpenjati Ciskeiovertime.The national / Transkeí This habitat is estuariesevident integrity from assessment aerial photographs showed thattaken the in Ciskei 1961. andOf the Transkei 129 estuaries estuaries included have changed in the little habitatnationalIn the Transkei integrity habitat estuaries,integrityscores of assessment plantloo. Of cover these, 44has 40estuaries been estuaries removed showed were as no founda resultchange in ofTranskei inagriculture area andcover and4 estuariesover mangrove time inand, Ciskei.harvesting. thus, had agricultureMgwalana,In the Ciskei (KeiskammaMtati estuaries, and Gqutywa plant Estuary). cover Estuaries), The has greatestbeen residential removed threats developments as to athe result conservation of (Biraroad constructionand status Mpekweni of the (e.g. Ciskeiestuaries) Great and Fish, andTranskei estuariesincrease.Future recreationalincludeBecause agriculture of andthe pastindustrial in politicalthe floodplains development history ofand this also unsustainable region poses we a threat are harvesting presented as the needof withmangroves. for a collectionwater abstraction of pristine will or developmentWaternear pristine Act and estuaries.can the hopefully National With beEnvironmental environmental dealt with in Managementa legislation manner that such Act will as1998, protect Resource-Directed future the estuarineurban, industrial environment.Measures or agricultural in the National DistributIonMangroves previouslyand state ofoccurred mangroves in 17 along estuaries the Transkei (Ward and coast Steinke 1982), but were found in only 14 of the 76 theEstuaries.estuaries Bulungula visited. Mangroves Estuary Complete were in the lost lossMzimvubu due of totrees drought. Estuary (7.5 ha) The were was drought lost evident due resulted toin floodingthe inMnyameni, the and mouth bank Mzimvubu of scour, the estuary while and mangrovesBulungulaclosing and in sinceremovedinundated been harvestedfor of woodthe mangroves leaving leaving only only for dead fivedead months tree stumps. stumps. (Knight Mangroves Ward pers. and comm.). in Steinkethe Mnyameni Consequently (1982) Estuaryrecorded the havetrees both been diedB. gymnorrhiza andcompletely have andincreasedNo new A. marina occurrences by a in total this of ofestuary. 17.6 mangroves ha in eight were of recorded the estuaries. in the Overall estuaries there surveyed, has been although little change tree cover in species has X gymnorrhizacomposition ofand the Rhizophora different estuaries mucronata. and theThe species mangrove recorded fern Acrostichum included Avicennia aureum marina,was recorded Bruguiera for the first timeOnlyEstuaries inBru this guiera area in which gymnorrhizain the mangrove Mkozi Estuary.occurred survival in is the threatened Mtamvuna include and Mzamba Mdumbi, Estuaries. Mzamba, TheseKobonqaba estuaries and receiveMtamvuna. no weredensityconservation found. of deadIn protected protection tree stumps estuaries and washarvesting suchgreater as has thanthe resulted Mtentu the number andin more Xora, of living than the trees50% density ofand the of no juveniletrees seedlings being trees orremoved. wasjuvenile higher. The trees withinunprotectedOnly the 18% estuaries of andthe mangroveseasily south accessible.of the occur Mzimvubu in protected River isareas expected such inas the nature fringe reserves. mangroves, Further as mostremoval are of mangroves researchTheRecommendation: problem and ofmanagement unsustainable level. harvesting of mangroves needs to be addressed at both a TECHNOLOGY TRANSFER freshwaterSince the project requirement commenced studies the to botanical determine importance the present rating status system and hasbotanical been usedimportance in a number of estuaries. of estuaries:TheseRecently, are theSwartkops,contract botanical studies Palmiet, importance funded Nhlabane by rating the andDepartment system Mhlathuze has of been Watersstudies. used Affair in estuary and Forestry reserve and studies included (Nahoon, the following reserveregionalNorthern estimateand Pondoland national for theestuaries, importance sixteen Mtata Pondoland and andsensitivity ten estuaries adjacent of estuaries was estuaries) possible to flow to because determinereduction. of theThe baselineecological study on information theintegrity, desktop providedimportanceLinks have by been ratingthe botanical established system importance-ratingto estuaries with CSIR in that(Durban) project. province. and Too AKwaZulu-Natal littleproposal data wasregarding Wildlifealso submitted other to apply aspects to the Marine werebotanical andavailable. Coastal ManagementtheInformation Environment) on to estuarine apply project the plant forbotanical estuaries distribution importance in the and Cape biodiversityrating region. system was to theprovided small tonorthern the CAPE KwaZulu-Natal (Cape Action estuaries. Plan for xi of projectGISSA-ISISDACST and has (Departmentdecision(South provided African support-systems ofinput Arts,Integrated on Culture, State toInformation of aidScience the government Environment and System) Technology). decision-making. isindicators a project The for fundedobjective Theestuaries. botanical by of the that State National importanceproject of the Innovationis Coastto rating develop and Fund StateInputWetlands wasof the provided EnvironmentConservation on the Reports distributionProgramme) will become of forestuarine the a Southlegal plants obligation African to Ms National Rin vanthe future.der Wetland Walt of Inventory DEAT (South African thebySocial Dr plants J and Turpie was Ecological (UCT).obtained ThisServices from project the (DWAF) botanical rated estuariesfunded importance-rating a projectbased on on theirproject.the prioritisationecological importance. of South African The information estuaries, forled ThatRecommendation: the results from the Prioritisation project be supported by all Government Departments. FURTHER RESEARCH Theunderstanding. dynamic nature This of appliesestuaries not and only the to influence botany but of thisto other on conservation fields as well. importance needs further havetheThe analyses. KwaZulu-Natal a high number This would estuaries of important aid therequire testingestuaries, more of theattention,as ithypothesis is the as transition these that estuariesthe zone northern between were KwaZulu-Natal not the adequately subtropical region represented and shouldtropical in regions.identificationThe Cape estuaries in the past should literature. be surveyed This would again, clarify as there the areclassification a number of thediscrepancies plant community with regard types to in species this region.estuariesSustainable where utilisation mangrove of mangroves survival is needs threatened. investigation. Management plans need to be initiated for those xii LIST OF PUBLICATIONS I CONFERENCE PRESENTATIONS DissertationsBotany,Riddin, T.University 1999. The of BotanicalPort Elizabeth. Importance 177 pp. of (Funded the Nhlabane by Richards Estuary. Bay M.Sc. Minerals). Dissertation, Department of Colloty,ThesisUniversity B.M. of2000. Port BotanicalElizabeth. Importance 202 pp. of Estuaries of the Former Ciskei/Transkei Region. Ph.D. Thesis, JournalAdams, J.B.articles and Bate, G.C. 1999. Growth and photosynthetic performance of Phragmites australis in estuarineCoetzee,Water SA J.C.,waters: 23 Adams, 81-93. A field J.B. and and experimental Bate, G.C. evaluation. 1997. A botanical Aquatic importance Botany 64 rating359-367. of selected Cape estuaries. inColloty,Wortmann, the flora B.M., ofJ., theAdams, Hearne, Swartkops J.B. J.W. and andEstuary Bate, Adams, overG.C. J.B. time.2000. 1997. Water The A use SAmathematical of26 a (4)161-170. botanical model importance of an estuarine rating to seagrass. assess changes EcologícaldistributionWortmann, ModellingofJ., estuarine Hearne, 98 J.W.macrophytes.137-149. and Adams, Ecological J.B. 1998. Modelling Evaluating 106 the213-232. effects of freshwater inflow on the ReportsFloraAdams, of theJ.B. Olifants and Bate, River G.C. Estuary. 1997. PreliminaryReport prepared Assessment for Environmentek, of the Effects CSIR of Altered on behalf Freshwater of the Department Flow on the of WaterFreshwaterAdams, Affairs J.B. Flow and and onBate, Forestry. the G.C. Mkomazi 21 1997. pp. Estuary. Preliminary Report Assessment prepared forof theJLB Botanical Smith Institute Status of and Ichthyology, Effects of onAltered behalf ofTugelaAdams, the Department River. J.B., Bate,In: Thukela of G.C. Water and Estuarine Affairs Wooldridge, and freshwater Forestry. T.W. 1997.requirements: 28 pp. The biological An initial condition assessment. of the lowerPrepared reaches by the of the Consortiumpp. for Estuarine Research and Management for the Department of Water Affairs and Forestry. 19 xl" AffairsAdams,Resource and J.B. Forestry. Managementand Bate, 24 G.C. pp. Plan. 1998. Report Floristic prepared Characteristics for Environmentek, of the Palmiet CSIR Estuary on behalf - Input of Department to Palmiet Waterof Water WateraAdams, Water Affairs J.B.,Resource Colloty,and Forestry.Management B.M. and 23 pp.Bate, Plan. G.C. Report 1998. prepared Floristic for Characteristics Environmentek, of CSIRthe Swartkops on behalf Estuary of Department - Input toof Vegetation.Adams, J.B., Submitted Bate,Riddin, G.C. T. to and and the Bate, Riddin,Institute G.C. T. for 1998. Water Freshwater Research. Requirements 30 pp. of the MhlathuzeNhlabane Estuary: Estuary: Vegetation.Wooldridge,Adams, J.B., Report T.H.Baird, 1999. submittedD., Bate,The Effect G.C., to the onCallahan, Institute the Kromme R.,for WaterScharler, Estuary Research. U., of Snow,a Single 20 G.S., pp. Freshwater Strydom, Release N., Whitfield, from theA.K. Mpofu and WaterDam.Colloty, SABAffairs B.M., Institute andAdams, Forestry. for J.B. Coastal and 105 Bate,Resource pp. G.C. Management1998. The Use Report of a Botanical Number C50.Importance Submitted Rating to DepartmentSystem to of Studies,AssessColtoty, Changes B.M.,Department Adams, in the of J.B. WaterFlora and of Affairs Bate,the Swartkops G.C.and Forestry. 1999. Estuary. Eastern 27 pp. Report Pondoland prepared Planning for Institute Reserve for Estimate Water Quality for Sixteen Estuariesestuaries.Colloty, BM., -Report Vegetation Adams, submitted J.B. Report. and to JLB Whitfield,Report Smith prepared A.K. Institute 1999. for on BackgroundDWAF. behalf of20 the pp. information Department on of the Water Mtata Affairs and tenand adjacent Forestry. 25Natal.Riddin, pp. Submitted T., Adams, to J.B. Richards and Bate, Bay G.C.MineraIs. 1999. 22 Botanical pp. importance rating of the Nhlabane Estuary, KwaZulu- Adams,Popular J.B. articles 1997. Working together for Water. UPE BulletIn. September 1997. Adams,Adams,Wetlands J.B. J.B. and Newsletter 1998. Bate, Managing G.C. 8 6-7. 1997. our Salt water marshes resources - Research - Estuaries on ofa threatenedSouth Africa. habitat. UPE FocusSouth 1998.African Page 8. xiv Adams,Cape EstuariesJ.B., Weston, Management B. and Taljaard, Programme S. 2000. Newsletter Implications Issue of4. the National Water Act for estuaries. Eastern Colloty,Management B. 1998.and Programme Adams, Rating J.B. the Newsletter 1999.importance Botanical Issue of estuarine3, importance Spring 1999.flora. of Veldppthe 4-5. Pondoland and Flora 38:estuaries. 35-36. Eastern Cape estuaries BookBaird,Adams, chapterD. J.B. (eds.) Bate, Estuaries G.C. and of O'Callaghan,SouthAfrica. M.91-118. 1999. Estuarine primary producers. In: Allanson, B.R. and ConferenceSouthColloty, African B.M., presentations estuariesAdams, J.B. including and Bate, the formerG.C. 1997. Ciskei The and development Transkei regions. of a botanical Oral presentation importance at scorethe South. for rating Afr. Soc.keyAdams, issues. of Aquat.J.B. ECSA and Sci. Bate, 29. 34th Estuarine G.C. Symposium, 1998. Coastal Freshwater Mtunzini, Sci. Assoc. requirementsKwaZulu-Natal. Symp., Univ.of SouthJune of Port1997. African Elizabeth. estuaries: 13-17 Case July studies 1998. and EstuarineColloty,Snow, G.C., B.M., Coastal Adams, Adams, Sciences J.B. J.B. and andAssoc. Bate, Bate, Symp.,G.C. G.C. 1998. Univ.1998. Predicting of Assessment Port Elizabeth. the effects of changes 13-17 of reduced July in estuaries1998. freshwater overtime. inflow ECSA29. on Vanestuarine 1998.Hutten, microalgae.T., Bate, G.C., ECSA Colloty, 29. Estuarine B.M. and CoastalAdams, Sci.J.B. Assoc.1998. The Symp., dynamics Univ. ofof Portmicroalgae Elizabeth. in temporarily 13-17 July closedapproach.Colloty, estuaries. B.M. S. 1999.Afr. Assoc.ECSA29. A botanical Bot. Estuarine 25th survey Ann. Coastal of Congr., estuaries Sci. 11-15 Assoc.in the January, former Symp., UNITRA, Transkei Univ. of Umtata.region. Port Elizabeth. A geomorphologic 13-17 July 1998. thepresentationAdams, new J.millennium. B., at Taljaard, presentation 22 S.to 26and at November Weston, B.1999, 1999. Wilderness. The National Water Act: Implications for estuaries. Oral 10th Southern African Marine Science Symposium. Land, Sea and People in xv ACKNOWLEDGEMENTS We would like to express our sincere thanks to the following organisations and people: TheDr Water Steve ResearchMitchell, WRC Commission Research for Manager, funding this for research;his support and input; AlanHay,Members Whitfield Prof. of T. andthe Jacobs, SteeringDr. Dirk Prof. vanCommittee Roy Driel) Lubke, for (Prof. their Prof. Charlesvaluable Sageran Breen, input Naidoo, and Mr. Ms.support;Mike Barbara Burns, Weston,Prof. Digby Prof. Cyrus, Tris Wooldridge,Mr. Duncan Dr. theTheBotany equipment field assistantsDepartment in order; who for survived: allowing theGavin use Snow, of their Tim facilities van Hattum, and to AndrewAyanda GouwsMatoti andand AlidaMike Badenhorst.Brassil for keeping To the TheMrs. Institute Joy Kritzinger for Coastal for excellentResources secretarial and Management, support; Departments of Geology and Geography, University of deserveAllPort those Elizabeth, their whom own we for story met the as inuse theit madeof Transkei, their for aerial a remarkableespecially photographs those journey. and that maps; provided a warm shelter or meal. These folks

xvi INTRODUCTION TABLE OF CONTENTS I 1.2 Study Approach LITERATURETHE STUDYAREA REVIEW 12 82 3.23.1 Bioogica1Introduction conservation3.2.1 Food supplies 1212 3.2.43.2.33.2.2 GenesNaturalBiological products control agents 1312 3.2.63.2.5 FutureEnvironmental options services 1413 3.3 Importance of conserving3.3.13.2.7 EconomicSubmerged estuarine and plantsmacrophytes recreational value of biodiversity 1415 3.3.43.3.33.3.2 MangrovesSaltReeds marshes and sedges 1615 3.53.4 PastEstuarine scientific importance information 3.5.1rating publishedPhysical indices environment on Transkei and and geomorphology Ciskei estuaries 201916 3.6 Mangroves 3.6.13.5.2 EstuarineIntroduction classification .. a geomorphologic approach 2220 3.6.33.6.2 MangroveThe ecology distribution of mangroves3.6.3.1 Mangrove swamps along the east coast of South Africa 2523 3.6.53.6.4 VegetationFactors affecting change the 3.6.3.2with colonisation tidal Location flat evolution and of successionmangroves of in mangroves South African estuaries 3026 3.6.83.6.73.6.6 TheImportanceMangrove importance vegetation and functionfor local change ofcommunities mangroves in response to floods, cyclones and changes in tidal regime 343332 3.6.103.6.9 Future Protecting threats mangrove and management forests 3534 4.24.14 A MaterialsIntroductionBOTANICAL and methods IMPORTANCE RATING SYSTEM FOR ESTUARIES 363736 4.2.24.2.1 AssessmentApplication of areathe botanical 4.2.2.1from aerial Functional importance photographs, importance rating past founula literature and field surveys 393837 4.2.2.44.2.2.34.2.2.2 PlantSpecies community richness typetype richnessrarity 4544 4.44.3 DiscussionResults 4.3.1 Botanical importance in the different biogeographic regions 504846 5 THE BOTANICAL IMPORTANCEREGION OF ESTUARIES IN THE FORMER CISKEI AND TRANSKEI 5252 5.35.25.1. ResultsMaterials Introduction and methods 52 5.4 Discussion and conclusionTHEPLANTS INFLUENCE IN THE OF FORMER THE PHYSICAL CISKEI AND ENVIRONMENT TRANSKEI REGION. ON THE DISTRIBUTION OF ESTUARINE 5453 6.26.1 MaterialsIntroduction and Methods6.2.1 Botanical surveys 5554 6.2.46.2.36.2.2 EstuarineOrdinationPhysical variables classification - a geomorphologic approach 55 6.46.3 ResultsDiscussion and conclusionTHE DEVELOPMENT OF A HABITAT INTEGRITY INDEX 716961 7.1 Introduction 71 7.2 The use of a habitat integrity index to determine the effect of development on the Swartkops Estuary xv iii 7.2.27.2.1 ResultsMaterials and Methods7.2.1.1 Assessment of aerial photographs, orthophoto maps and past literature 7372 7.2.2.37.2.2.27.2.2.1 SubmergedBenthicPhytoplankton microalgae macrophytes - Zostera capensis Setchell (eelgrass) 73 7.2.2.67.2.2.57.2.2.4 ReedsSaltFunctional marsh and sedges importance rating 807974 7.3 Eastern Pondoland 7.2.47.2.3estuaries ConclusionDiscussion 8382 7.3.37.3.27.3.1 ResultsMaterialsIntroduction and methods 8483 7.3.3.47.3.37.3.3.1 2 BotanicalRegional functionalraritysurveys of Pondoland importance estuaries 868584 7.4 National habitat integrity7.4.17.3.4 MaterialsDiscussion of estuaries and and methods conclusion 8887 8 DISTRIBUTION AND7.4.37.4.2 STATE ResultsDiscussion OF TRANSKEI MANGROVES 939189 8.28.1 MaterialsIntroduction and methods 9493 8.2.38.2.28.2.1 MangroveMappingField surveys and state image analysis 94 8.48.3 ResultsDiscussion and conclusion 104100 95 109.19 GENERAL REFERENCESFuture research CONCLUSIONS AND RECOMMENDATIONS 107106 11 APPENDICES xix 119 Table 3.1: A summary (Ruitenbeek 1992) of the economic value of mangroves based on potential gain in US$ perhaperannum. LIST OF TABLES 14 Table 3.3:3.2: The classification of estuaries derivedcompiled by by Harrison Harrison et et aI. aI. (1 (1 999a; 997a; i 999b)i 997b) for for 43 16 of of the the Transkei Ciskei estuaries. The Whitfield estuarine classification is also shown. 21 Table 3.4: Distribution of mangroves along the South African coast and within estuaries (adapted from Steinke,estuaries.Intertidal 1995). The position; Whitfield Key H- Estuarine = estuarineHigh; M location: = classificationMid; L D= Low. is also shown Downstream; I = Intermediate; U Upstream 2721 Table 4.1:3.5: PrimarySummary productivity of mangroves values species for the found nine estuarinealong the plantSouth community African coast types with inundation and salinitytolerances as well as plant succession status 2739 Table 4.3:4.2: The rangecommunity of normalised types and functional average importanceproductivity scores values and for thethe differentrespective estuarine functional plant importance communityscorestypes used used in in the the functional botanical importanceimportance rating.rating system. 43 Table 4.5:4.4: TheFunctional number importance of species of that the might Mngazana be found Estuary in an foundestuary in andthe Transkeithe respective region species of the Eastern richness Capescore.Province. The species richness scores were obtained using a percentile range test. 44 Table 4.6: The number of community types that might be found in an estuary and the respective communityrichness score. 45 Table 4.7:4.8: RarityThe 36 weights estuaries and with the therespective highest communitybotanical importance rarity scores scores in South Africa. The components ofinthe bold. botanical importance formula are shown and the final botanical importance scores are indicated 47 Table 4.10:4.9:5.1: ThirtyBotanical Twenty warm eight importance temperate estuaries of estuaries withall 16 the Ciskei highestwith estuariesthe scoreshighest and in botanical the the subtropical 30 Transkeiimportance region estuaries scores. with the highest 4948 Table 6.1: The classification of estuaries compiled by Harrison et al. (1999a; 1999b) for the 16 Ciskei estuaries.scores. (The estuarine classes (Whitfield 1992) are also shown.) 5653 Table 7.1:6.2: SummaryThe classification of the characteristics of estuaries derived of Zostera by Harrison capensis et found al. (1999) in the for Swartkops 43 of the EstuaryTranskei estuaries.The Whitfield estuarine classification is also shown. 7456 xx Table 7.3:7.2: Summary of the change in the area covered by supratidalintertidal salt salt marsh marsh as calculated calculated from from available available maps(1:10000)maps, aerial photographs (Trig. Survey and Department of Environmental Affairs) and orthophoto 78 Table 7.4: Summary of the change in the area covered by reeds and sedges calculated from available maps,aerialmapsmaps, photographs (1:10000).aerial photographs MSHWM (Trig. Survey (Trig. = Mean Survey and spring Department and high Department water of Environmental mark. of Environmental Affairs) and orthophoto maps Affairs) and orthophoto 79 Table 7.5: Functional importance scores ranked in decreasing order of importance for a number of South African(1:10 000). estuaries. MSHWM Normalised = Mean spring scores high are wateralso presented mark 8179 Table 7.7:7.6: PresentList of plant (1998) species community found inrichness the estuaries and functional of the Pondoland importance region. rating of estuaries found in the PermanentlyPondoland region. open estuariesEstuaries areare shownranked in in bold. decreasing order of functional importance. 8684 Table 7.8: Past (1961) and present (1998) functional importance scores of selected estuaries found along theascoresSouth percentage. Africanare calculated coastline.Pondoland for Estuarieseach estuaries estuary are are inranked shown order intoin decreasingbold.illustrate the order change of importance. in functional The normalised importance as 87 Table 7.9:7.10: The The habitat habitat integrity integrity scores scores applied of 124 to South the ranges African for estuaries. percentage A score deviation of 100 from represents natural scores.... no change 88 over time, while lower scores reflect a degree of change to the estuary. 90 Table 8.1:8.2: ATree comparison density of of respective species found mangrove in this speciessurvey compared found in the with Transkei past surveys, estuaries including comments onprotectionpossible reason for changes in composition and total area covered, as well as conservation 9998

xxi LIST OF FIGURES Figure 1.2:1.1: Flow diagramchart depicting showing the the components layout of the of sectionsthe botanical in this importance study rating and habitat integrity index developed in this study. 45 Figure 2.2a:2.1: The The Ciskei Transkei study study region, region. with There sixteen are estuaries. 120 river The outlets, Great but Fish, only Keiskamma 76 of these andare consideredTyolomnqa Estuaries are the only permanently open estuaries. 9 Figure 4.12.2b: a: TheGraphic Transkei representation study region, of thefrom wide the rangeMtakatye of raw River data to scoresthe Mtamvuna for each River of the (Port individual Edward) estuarine. Estuaries shown are from Kel Mouth (Great Kei River) to Mtakatye River. 1110 Figure 4.1 b: Graphic representation of the wide range of raw data scores for each of the individual componentsare shown. used in the botanical importance rating. Only ten estuaries with the highest scores 41 Figure 6.1: CCA ordination of plant species presence/absence in Ciskei and Transkei estuaries that were distributionsurveyed. of Spatialare plant shown. speciesseparation are ofshown. the estuaries Environmental in relation variables to environmental include, water variables column and depth, the 42 Figure 6.2: CCA ordination of the plant species presence/absence in Ciskei and Transkei estuaries that were surveyed.environmentalaverage salinity Spatial correlation and separation secchi for depth. thein relation first The three tableto environmentalaxes. insert shows variables the eigenvalues and distribution and species patterns - of 65 Figure 6.3: A summary of the three groups of permanently open estuaries and associated plant community theattenuation.plant first species.three The axes Environmentaltable insert shows variables the eigenvalues include, water and speciescolumn depth,- environmental average salinitycorrelation and forlight 66 Figure 6.4: A summary of the three groups of temporarily open/closed estuaries and associated plant communitydominatedtypes found bytypes in salt this foundmarsh study. in andThere this those study. is a containing transition A transition atswamp theis shown Mngazana forest between species. Estuary estuaries between that the have estuaries salt marsh 67 FigureFigure 7.2: 7.1: The The past Swartkops plant cover Estuary of the showing Swartkops the Estuarydistribution before of surrounding 1939. developments. and those that contain swamp forest 766875 Figure 7.4:7.3: The change1998 estuarine in area plantcover coverx productivity of the Swartkops values over Estuary time for the respective plant community types in the Swartkops Estuary 8177 Figure 8.1: A map of the Eastern Cape Province showing estuaries that support mangrove communities. andvaluesPresent - = weredecrease area taken (ha) in from mangroveand Ward percentage and cover Steinke of total (1982). area cover Key: for+ = the increase region in is area given. cover, The pastO = noarea change cover 97 Plate 1 .1: The database form that displays general information on each South African estuary. This includes LIST OF PLATES estuaries.estuaryinformationbiogeographic and a onplace region,this for estuary comments. province, can beestuary Each found of classification inthese Whitfield fields (2000). andcan thebe There usedpage tonumberis searchalso a where photographor sort further the for each 6 Plate 3.1:1.2: The Mngazanabotanical data Estuary, in the the database largest includesand most past complex and present mangrove area system cover ofalong each the of Transkeithe plantThreecommunity coast. mangrove types speciesfound in are the present estuary andand coverthe calculated approximately functional 145 ha.importance scores. 29 7 PlatePlate 6.2: 6.1: The The Jujura Sinangwana Estuary inEstuary the former found Transkei in the former is classified Transkei as regiona Class is 1 classified B estuary. as a temporarilyopen/closednear permanently estuary open(Class system lA). due to its large catchment rather than the tidal prism. The tidal lt has a surface area of ca. 4.5 ha lt is an example of a 57 Plate 6.3: The Qolora Estuary is a large temporarily open estuary, typical of Class 2 estuaries. This typequicklyestuaryamplitude of duehas was toa perched the1.2 highm at wavebarrier the mouth energy and duringonly conditions breaches a spring along aftertide the onextended coast.19/04/98 rainfall events. The mouth closes 5857 Plate 6.4: An example of a Class 3 estuary which is a large system with a tidal prism that maintains a neargeology.(Classpermanently The3B) isKobonqaba opencharacterised inlet. EstuaryDifferences by tidal (Class mud in the3A) flats. size has andsand location flats at ofthe sand/mudflats mouth; the Mngazana are due to Estuary the local 59 Plate 7.1:6.5: TheClass Mkambati 4 estuaries, River such is not as consideredthe Mbashe, to include be an estuaryall river-dominated as it flows directly estuaries into the sea over a seriesof waterfalls 8560 LIST OF ABBREVIATIONS BHI - Biological Health Index BIRBI - Botanical Importance Rating CDICCA - CommunityCanonical Correspondence Degradation Index Analysis CSIRCERM - CouncilConsortium for Scientific for Estuarine and IndustrialResearch Researchand Management EHIDBH - EstuarineDiameter atHealth Breast Index Height included ¡n the RDM of the National Water Act FISFHI - FunctionalFish Health Importance Index (East Score Coast Programme - CS IR, KwaZulu-Natal) RDMMSHWM - ofResourceMean the SpringNational Directed High Water WaterMeasures Act MarkNo 36of theof 1998 Department of Water Affairs ¡n terms

xxiv Benthic Bottom-living GLOSSARY OF TERMS BiomeBiomass MajorparticularA quantitative ecological area estimationor regionsvolume. identifiedof the total by weight the type of livingof vegetation material infound a landscape. in a CommunityBotanical importance AestuaryThe clearly contribution based defined on of assemblageenergy the estuarine input. of plantsplants and/orto the totalanimals conservation distinguishable status from of an DiatomsDetritus A classOrganicother suchof algaedebris assemblages. with from distinct decomposing pigments plants and andsiliceous animals. cell walls. They are an EcologyDynamic TheRelatingimportant study to componentof ongoing the structure and of thenatural and phytoplankton. functions change. of ecosystems, particularly the Ecosystem Anhabitats.dynamic interacting co-evolution and interdependent of relationships natural of systemorganisms, of organisms, communities biotic and Epiphyte waterA plantcommunities or living nourishment on and the theirsurface from habitats. it. of any substrate without necessarily deriving Estuarine bay TheselargeEstuarine tidal systems baysprism havemight allowing permanently either for beregular natural open replacement (Knysna deep mouths lagoon) of the (>'3 estuarineor m).artificial They water. such have as a Estuarine classification permanentlyAthe classification dredging openactivities system estuaries, in used the mouthtotemporarily classify and theharbour open/closed different of Durban types estuaries, of Bay. estuaries, estuarine viz. morphology,havelakes, defined estuarine barriera geomorphologic bays type and and river physical mouthsclassification conditions. (Whitfield for estuaries 1992). Cooper based eton al. (1999) Estuarine healthcondition Theactivities conditionstate, have condition ofchanged each or estuary, performance the function based orof on viabilityan the estuary degree of a as particular to defined which humansystem.in terms of importanceestuarysome desired can scorebe endpoint determined with the (Fairweather score by comparing of the 1999). "pristine" the The present orbotanical past day condition. botanical health of an Estuarine lake examplethatThe ariseslower of reaches fromsuch expansive a systemof these is lakesystems the areas Swartvlei are forming typically on the the asouthern upper narrow reaches. estuarinecape coast. An channel xxv Estuary temporarilyA partiafly enclosed open to thecoastal sea andbody within of water which that there is either is a measurablepermanently variation or Eutrophication Thedrainage.of processsalinity due by which to the amixture body of of water sea water is greatly with enrichedriver water by derived the natural from or land types.artificial(increased addition productivity) of nutrients. and Botanically adverse affects this may (smothering result in bothby dominant beneficial plant FluvialFlocculation OriginatingcontactThe settlement with from seawater. or rivers. coagulation of river-borne particles when they come into HabitatGeomorphology plantAreaThe study ofare natural met. of land environment form or topography. in which the requirements of a specific animal or MacrophyteIntertidalHalophytes AnyAnPlants area large betweenwhich multicellular can the tolerate highest plant salineas and opposed lowest conditions. tidalto small levels. ones. Aquatic macrophytes Mangrove forest Associatedmay float at with the surfacesaline or or brackish be submerged water, developsand/or rooted on tropical on the and bottom. . . (mangal) RhizophoraSouthsubtropical African coastsmucronata. species and include; tidal flats Avicennia of protected marína, bays Bruguiera and estuaries. gymnorrhíza, Dominant estuaryPermanentlyPeriphyton open horizontalOpenPlants to adhering the salinity sea toand gradient parts experience of rootedbetween daily aquatic the tidal head plants. fluctuations. and mouth There of the is estuary. normally The a Phytoplankton theircatchmentsUsually natural single ofcondition these cell plantsestuaries and ensure comprised may the be mouthsoflarge species and remain thebelonging rivers open. are to groupsperennial such in as PlantPlankton community type AMicroscopicgreen, term blueused greenanimalsto describe algae, or plants estuarine dinoflagellates, which botanical float diatoms or groupsdrift passively and such flagellate as in intertidal the microalgae. water. salt Primary productivity inorganicThemarsh, hourly, which carbon daily fail andorto adhereannual water productiontothrough the definition photosynthesis of biomass, of a true i.e. into community. the carbohydrates conversion of and Reeds source.Plantsplant structural belonging One typical components. to thespecies family is Poaceae the common that reedare rooted Phragmites within australis.or near a water RiverRiparian mouth dominateTheseAdjacent systems tothe or system. on have the largebanks Tidal catchments prismsof rivers, are streams withrestricted, high or meanlakes. e.g. Great annual Fish runoff and that Salinity InAMzimvubu measureestuaries Rivers. of the the ions total are quantity mainly ofNaCI. dissolved ions in water, measured in g. Salt marsh withinAreasdifferent thesein estuaries areas areas are showingare inundated termed regular halophytes by tides.zonation Plants due reflecting to that their have abilitythe lengthadapted to survive of totime survive the Sedges riverine,Plantshigh salt of lacustrine, loadsa brackish which bogwet induce (vlei)habitat osmotic and that temporary are stresses. found moist as components areas. Species of estuarine, include; Standing biomass/stock decomposers)TheSchoenop/ectus total mass orof aall littoralis,particular living organisms Scirpus set of thesenodosus. (producers, (e.g. species) consumers present and in an Submerged macrophytes intertidalSubmergedecosystem, substrata, usuallymacrophytes expressedwhose are leaves plants as dryand rooted weight stems in perare both unitcompletely soft area. subtidal submerged and low for Supratidal ThatRuppiamost portionstates spp. ofof thea tidal tide. flat Species that lies include above Zostera the level capensis, of mean Halophilahigh spring ova/is, water Swamp forest Swampbyand storm is inundated forest surges species only occasionally are associated by exceptionalwith brackish tides estuaries. or tides Characteristic augmented estuaryTemporarily open/closed sandSuchspecies barestuaries are which Hibiscus areforms blocked tiliaceus at the from mouth. and the Barringtonia Thesea forclosure varying racemosa. of thelengths mouth of times usually by a a catchments,nearshoreresult of low marine e.g.river Mpekweni, flow, environment. combined Mgwalana Most with oflongshore and these Bira estuaries Estuariessand movement have along small the in theCiskei Trophic level A divisionprimarycoast. ofproducers, a food chain or as defined secondary by the or methodtertiary consumers.of obtaining food either as Wetlands WetlandsenoughAreas that to generally supportare inundated vegetation include or swamps,saturated adapted marshes, by to surfacelife in bogssaturated or groundwaters and similarsoil conditions. areas. frequently (BlakeWith increasing 1991), management demands being of our placed resources on natural has become resources crucial caused (Morant by an and increase Quinn in1999). the human population 1. INTRODUCTION lt has become andnecessaryThe waterdevelopment use.to report Without of and importance thissummarise the functioningrating scientific indices of information thefor estuariesnatural thatenvironment in canrecent focus years will policy, behas impeded planningbecome (Kotze essentialand regulation 1999). to of land summariseTheserating isdecisions one and such communicate or method objectives that scientific could could include be information used the in determinationthe to implementationwater resource of estuarine ofmanagers. management flow Therequirements, botanicaldecisions importanceconservationor objectives. importance'ResourceProtection Directedof or water priority resourcesMeasures' and the habitat(e.g. (RDM). estuaries) integrity RDM will ofin individualtheoptimise National South estuaries. Water Africa's Act ofwater 1998 resources requires theon aimplementation catchment of Theofbasis, priority conservation while or ensuringimportant of estuaries sufficient estuaries in water thatSouth are to Africa sustaincurrently is thean under importantenvironment. pressure issue. Furthermore,or Theseface future are productiveRDMpressures require (Turpiesystems the identification et that al. 1999). inTheprovide water functions habitatquality of forof an thea estuary number river waterare of estuarineseverely (Allanson restrictedplants 1992; and Adams if animalfreshwater et speciesal. 1992).flow (Dayis Thesealtered 1981; estuaries through Grindley abstraction can and only Heydorn function or changes 1979). properlywereThe botanical discussed if some importance inform a previous of habitat of South Water integrity African Research is maintained.estuaries Commission and the relationshipProject (Adams between et al. plants 1996). and That water project supply Capedevelopedplant coast community a 33 formula estuaries types that wereandrated the rated estuaries closeness (Coetzee according of etthe al. association to1997). the area A recommendation betweenof estuarine the plantsplants, from and its the condition, the Water estuary. Research the Along number the of thehighCommission estuaries conservation of Project Ciskei status (Adamsand alongTranskei. et theal. 1996)wholeNew communitywas South that African the types rating coast. were should The included befocus extended inof the this importance projectto identify has estuariesrating, been tonamely surveywith a theimprovementsphytoplankton, refined formula, tomangroves, the is botanical defined macroalgae as importance the contribution and rating swamp formulaof the forests. plants were Hence, to necessary. the conservationa number Botanical of refinementsimportance importance, ofand the as estuary.used in communityenergyThis is basedinput type to on higher richness the size trophic and plantlevelsnumber community (i.e. of primarydifferent type production). plant rarity community have Means also typesbeen of assessing andincluded. their speciescontribution richness, in the plantform of 1 The revised formula can now be applied to any South African estuary and in this study was used to rate the determineinformation.estuaries within botanical The both revised importance the studybotanical region and importance estuarine and the remainder health.rating has ofalso the been South used African in the estuaries RDM for that estuaries had available to In summary the objectives of TothisCiskei extend project and the were: Transkei botanical region importance (Section rating 4, 5 system and 7). of Cape estuaries to include estuaries in the former To(Section provideincorporate 4)baseline a fifth data plant on community plant community type, i.e. structure mangroves and intodistribution the botanical in relation importance to freshwater rating inputsystem in a usedToregion translate in where decision scientific little support data information exists (Section presently on3). the (Sections freshwater 6 andrequirement 8). of mangroves into management tolls to be whereandFor the eachmangroves associated estuary occurred, physicalvisited the conditionsspecies major speciescomposition, (salinity, composition temperature tree density of the and and different inundation age were plant patterns)used community to determine measured. types werethe In structureestuaries assessed and1.2 status STUDY of the APPROACH mangroves found in this region. theBotanical Eastern surveys Cape wereProvince conducted (September within 1997the 92 July estuaries 1998). foundThe data in the available former Transkeifor each andestuary Ciskei include: regions of chlorophyll-anumberonce-off ofmeasurement differentand nitrate plant concentrations of communitysalinity, temperature, types (habitat depth, types) secchi depth, water column speciesareaidentification covered composition by of different rare or endemicplant community plant species types or(past those and with present limited values) populations A databaseinformation waswill was be constructed capturedavailable and asusing a stored stand-alone Microsoft in a series Access program of 97forms that (version will(data include for input Office notwindows 2000only information also- Plates available). 1.1 on and the All 1.2). Ciskei the The and Transkei estuaries, but all South African systems. Currently information on 274 (94% of the total in South 2 inexample,Africa) the supratidal estuaries if one wantedsalt has marsh been to know fieldincluded. (Platehow manyAny 1 .2) of Southand the 54fields African estuaries (see estuaries Plate will be 1.1. haveretrieved. and supratidal 1.2) can saltbe used marsh, in atype search. in >1 For ha Botanica!These data importance were then of usedan estuary to determine: which includes species and community richness, plant community type botanicalproductivityrarity and importancefunctional value for importance eachrating plant is demonstrated (i.e.community area covered typeby comparing Figure by different 2.1). the plantCiskei community and Transkei types estuaries multiplied with by 93 an other average In Sections 4 and 5 the application of the TranskeifieldSouth surveys African estuaries. was systems. used toIn establishSection 6 which (Figure factors 1 .2) contributedthe information to the on high the physicalbotanical environment importance obtainedof Ciskei inand the andchangesThe presenthabitat in area integrityaerial covered photographs. or health by the of different Thean estuary functional plant can community importance be determined types is then isusing measured calculated the functional over using time theimportance (Fig. earliest 1.1) and usingscore. most past The Swartkopsdifferencerecent area inEstuary values past and andmeasuring present the habitat changesfunctional integrity in importance plant score cover is calculated scores from photographs (Fig. as the1.1). deviation This and was maps from tested that natural, spannedin a study i.e. 100a of period theless theof fiftyCapeestimate years Province (Colloty of the (Northernestuarine et aI. 2000). waterTranskei). The reserve. habitat These These integrity case 16 studies was estuaries also also determined are lead found to further infor the 16 refinement Pondoland estuaries ofin region athe planning habitat of the integrityEastern discussesmangroveindex and the inlosses distribution total have129 estuaries occurred and status werewere of mangrovescomparedidentified and on in athe national studyfactors region.basis causing (Section Estuaries mangrove 7, whereFig. loss 1.2). the were Section greatest identified. 8 (Fig. 1.2) conservationSectionimportance 9 (Fig. ofrating 1.2) estuaries. isand a summary how this canthat bediscusses used to theset usemanagement of the information objectives obtained or make in recommendationsthe botanical for the

3 Habitat integrity Botanical importance= sum of components condition, i.e. 100 importance score from natural= deviation in functional - difference in functional importancE Functional importance listed below 3. Calculate difference = Area of plant coverSpecies (ha) richness x productivity functional importancein past and present scores Plant community type= No. of plant species 2. Determine functional importance of past and present states No. of plant community richness types 1. Measure area covered by differnt = OccurrencePlant community of types type in South Africa rarity using earliest and most recent plant community typesaerial photographs Figure 1.1 Flow chart depicting the components of the botanical importance rating and habitat integrity index developed in this study. 4 Botanica' importanèe Section 4 Development of botanical importance rating in the national rating of estuariesand protocol forBotanical future use importance of Section 5 The influence of the physical environment onCiskei plant distributionand Transkei in Sectionestuaries 6 Ciskei and Transkei estuariesHabit t integri Development of Habitat Integrity Index Section 7 development on the SwartkopsThe use Estuaryof a habitat integrity index to determine the affect of (Section 7.2) Eastern Pondoland estuaries (Section 7.3) National habitat integrity (Sectionof estuaries7.4) mangroves along the Transkei coast Distribution and state of Section 8 Figure 1 .2: Flow diagram showing the layout of the sections in this study. 5 Plate 1 .1: The database form that displays general information on each South African estuary. This searchphotographfurtherincludes informationor biogeographic sort for the each estuaries. on estuary this region, estuary and province, a can place be estuaryforfound comments. in classification Whitfield Each (2000). ofand these theThere fieldspage is alsonumbercan bea used where to 6 Plate 1 .2: The botanical data in the database includes past and present area cover of each of the plantcommunity types found in the estuary and the calculated functional importance scores. 7 2. THE STUDYAREA TheThereThis Ciskei region has and been was Transkei politicallyno previous region unstable botanicalwere, dueuntil, research to 1994 a series South on of estuaries militaryAfrican politicalcoupsin Ciskei and elections (Whitfield research independent 2000). activities Estuaries were homelands. almost in the nil. GrindleystructureTranskei (1979)wereand status excluded conducted of mangroves from earlier botanical studies ¡n this study region.on thefor moreMtata,Muir (1937),than Mbashe, 11 West years Mngazana, (1944), and little MacNae Mntafufu is known (1963) and about Mtentu and the Branch current Estuaries. and communitiesAfricanMolI et al.estuaries, (1971)were cover while in 37the Ward estuaries, first and to give Steinke including a complete (1982) the Transkei.accountdescribed of Research thethe distributiondistribution by the and ofUniversity all extent mangroves ofof mangroveTranskei in 37 South Greatstudiesconcentrated Kei, by Mbashe,the on Universities the Mtata ethnobotanical andof Transkei Mngazana value and Estuariesof Port the Elizabeth terrestrial respectively considered forest (Dye plants(Johnson zooplankton,1977, 1978, and 1983a,crustacea Cawe 1983b; 1987). and Emmersonfish Zoological of the andThe1977). McGwynneCiskei lies between 1992; Plumstead the Great 1984, Fish (33°1990; 30' Plumstead S; 27° 08' et E) al. and 1989a, Tyolomnqa 1989b, (33°1991 14'S; and Wooldridge27° 35' E) FJvers 1974 anda meanheadlandsdistance spring of joinedca. water 75 bykm mark, a (Fig. sndy sand 2.1). beach. being This These placedportion mouth there of the barriersby coast heavy is of madeseas. the estuaries Fourteenup of a series areestuaries usually of small are perched baysfound with inabove this rocky region,the TheseTranske,ibut only are three the mostly Ciskei are holidaypermanently has numerous houses, open while recreation (Great the Mpekweni,Fish, and Keiskammaresidential Old Woman's developments and Tyolomnqa and Great on Estuaries).the Fish banks Estuaries of Compared eight have estuaries. to the casino/hotelE)The to Transkei the boundary developments. coast betweenis a rugged the andEastern undeveloped Cape and region KwaZulu-Natal extending provincesfrom the Great (Mtamvuna Kei River River, (32° 31° 41' 04' 5 28°S 30° 23' Bureauranged11' E)(Fig. between1997-1999). 2.2). The750 averagemm.y1 (southern temperatures Transkei) ranged and between 1100 mm.y1 't6°C (northern(winter) and Transkei) 26°C (summer) (South African and rainfall Weather Theoccurbetween Transkei along the coast, the warm coast, also temperate ofknown which asand 76 the subtropicalare Wild estuaries Coast, biogeographic (Fig.is approximately 2.2). Seventeen regions. 270 One kmof these in hundred length estuaries and and forms twenty are permanentlythe river transition outlets thatopen,nineteen are 58 afforded temporarily percent conservation of open/closed the coastline, protection and while one include the is aremaining river the mouthMtamvuna, coastal (Fig. Msikaba,land2.2). isFive under Mtentu,marine tribal and tenure. Mbashenature The reserves Estuaries. only estuaries cover The southern portion of this region is composed of coastal lowlands and meandering rivers while the north 8 aconsists highbeen biodiversity. identified of steep (Johnsonvalleys Some and 900 and gorges. grass Cawe and About1987). forest half plant the coastlinespecies is covered by indigenous with commercial and homeopathic value have coastal forest that has t yolomnqa Peddi hweIe-hwele Ngainisa iwane Gqu!ywa aculura ii(eiskammaan FIIodon pekweni ati gwalana ira 333O' ç 7Great Fish AIfrd Old Woman's Scale 1: 500000 N Figure 2.1: The Ciskei study region, with sixteen estuaries. The Great Fish, Keiskamma and Tyolomnqa Estuaries are the only permanently open estuaries. 9 o

Dwesa Natur Willowvale Qo, Reserve Sce1:4 323O Grew K Kei Mouth Sc*1:4O Figure 2.2a: The Transkei study region. There are 120 river outlets, but only 76 of these are River.considered estuarine. Estuaries shown are from Kei Mouth (Great Kei River) to Mtakatye lo lagstaff Mer'u Kwiya iSc1.4-N 31W SiakaReserve Nature Mzubu t. Johns: HiulekaReserve Nature /takye Scel:4 Figure 2.2b: The Transkei study region, from the Mtakatye River to the Mtamvuna River (Port Edward). 11 3. LITERATURE REVIEW 3.1In INTRODUCTION this study a number of topics have been included. These range from biological conservation to the hastrendsdistribution been in eachpeer of mangroves ofreviewed the sections. and and published, theirItmust environmental be a acknowledged vast amount tolerances. of that information although Thus, thisexists all literaturethe on information the reviewWorld used Widesummarises inWeb this and review current is updated3.2 BIOLOGICAL on a monthly CONSERVATION basis. of Oneestuaries. aspect However, that the botanical it also intended importance that inrating this reviewis concerned a few reasonswith is identifying for the need the toconservation conserve estuarine importance importancebiologicalplants is also diversity on presented natural and resources the (Richardson ecosystem. and justify1995). The the majorThe protection corner-stone aim of biological of species of biological conservation or ecosystems conservation is to either place is using the value species a orselected or environmentspecies3.2.1 Food or argument supplies for future for generations biodiversity include: (Bryant 1998). Arguments that are used for the protection of the natural Aboutofconsumption. the 80 world's 000 plants foodAs the speciescomes global fromare economy thought 15 species strengthens, to be (Bryant edible 1998).manwith onlyhas The concentratedabout red mangrove 150 species on Rhizophora fewer being species used mucronata for so human that today Lam. 90% andtypeseedlings eatenof fruit haveas juice. a vegetablebeen The used black (fruit, as mangrove a seedlingsfood source Bruguiera and in terminal times gymnorrhiza of buds) famine, (Bandaranayake (L.) as wellLam., as, is fuel,used 1998). tannin, as a source dye, wine, of starch tea anda (fruits) 3.2.2Wild plantsGenes are also important sources of genes that can confer useful properties to conventional crops. The cropoverpotato disasterEurope was brought (Richardsonin the from19th CenturyPeru 1995). to Europe Inand Ireland millions in theit became of 15th people century the in staple Ireland and diet.eventually starved. A disease Ait waswild of cultivatedrelative potatoes of ascausedthe a potatocrop a plantmajor was all butfoundobtained also in thePeru (Bryantgenomes. and when 1998). it wasThis hybridized emphasises with the the reasons standard for crop conservation plant, a disease-resistant of not only the genera variety and was species, 12 3.2.3 Biological control agents itssystems.On original many Usually,occasions, home (Dugan the introduced best 1993). control exotic methods animals consist or plants of having have tobecome find the serious natural invaders antagonists of the of the species in natural 3.2.4Themost potential Natural powerful for products discoveringarguments formedical conservation compounds of biological in wild organisms diversity (Bryantis enormous, 1998). and The provides one of the pharmaceutical industry prescriptiondrugsis much are takenmore drugs directlydependent are derived from on plants fromnatural higheror productsare chemicallyplants. than Some is modified generally include versions morphine,realized. of About plantcodeine, substances.a quarter quinine, of Aboutatropine,all 121 and prescription digitaliscertainSouth (BryantAfrica, Atriplex while1998). species, the Sarcocornia leaves also found of Suaeda salt in saltmarsh marítimamarshes, species L. has havecan anti-leukemia be been used used as treatmentinproperties remedies against (Bandaranayake for stomach hepatitis. ailments The 1998). bark of in 3.2.5Others1999). Environmental terms A few used decades include services ago, ecosystem the water services in the Chesapeake (Richardson Bay1995) was or clearfunctional because importance oysters (Turpiewere filtering et al. out occursofparticles the oyster (Bryant at a removedrate 1998). estimated Thethrough environmental to over-harvesting,be the equivalent or functional the of accumulationthe serviceentire volume that of estuarinesilt of and the other bay plants every particulates three days. no longer With 99% provide is discussed in termsfurtherconservation of detail fisheries, in Sectionsof thesematerials ecosystems.3.3 andand recreation/tourism3.6, asSecond, this is probablyto this (Richardson is the indirectstrongest 1995). economic argument value currently that estuaries available generatefor the in 3.2.6someThe future Futurespecies value options that of we our now systems consider to our insignificant successors or is even unknown. harmful. Perhaps Many ofthey the will natural need sources vast quantities of of medicines Africanareone in factof gardens, the poisonous most would useful (Bryant be antibiotics a source 1998). or ofNobody thean anti-leukemiaMadagascar could have periwinkledrug. predicted The (Catharanthusmainthat bread reason mould for preserving would be not only roseus), common in South the source of (Bryantplantsspecies on 1998).but the also planet, genetic can variabilityadapt to unforeseen of wild and changingdomesticated circumstances species is sothat that we we,are andnot capablethe other of animals imagining and 13 3.2.7 Economic and recreational value of biodiversity nurseryservicesThe economic habitat or function value for fish. of of the mangrovesMangroves mangroves, hashave i.e. been also protection widelybeen valued researched.of property on the through Value basis has ofbank yield been stabilisation, of placed materials on filtration ecosystemssuch as of wood water, attractionangling,products canoeing orfor food the ecotourism(Table and sailing 3.1). tradeEstuaries are all in commonsouthern are also onAfrica. popular estuaries The for revenue (Rammrecreational generated1990; activities. Begg by 1978). this Swimming, ecotourism This is anboating, canadded form tourist an integral part of the local economic development of an area (BeggTable 1978). 3.1: A summary (Ruitenbeek 1992) of the economic value of mangroves based on potential gain in US$ per ha per annum. Date19741973 of Study Country TrinidadPuerto Rico, and USATobago MangroveProduct/ServiceFisheryMangroveEcosystem productsecosystem ecosystem (US$/ha/year) Value 1 550 125500 197619761974 TrinidadFijFiji i and Tobago FisheryMangroveRecreation,Forestry products products ecosystem tourism 950 -1 250 640200 70 197919781976 ThailandIndonesiaQueensland,Indonesia Australia FisheryForestry products products 10-20 1 975 130 50 198219801979 ThailandMalaysia FisheryForestry products products 30-2 000 2 772 750225 25 1992198619851981-821982 ThailandIndonesiaMalaysiaIndiaBrazil MangroveForestryMangroveFishery products ecosystemproducts ecosystem 30 - 400 11561113144 800 769 3.3 IMPORTANCE OF CONSERVING ESTUARINE PLANTS formenvironment.Estuaries and character are Estuaries important of an are estuary because dynamic will they ecosystemsbe havedetermined a number that by occur aof number functional at the of interface factors.roles (ecosystem betweenThese physical land services) and factors sea. in the Thus,are coastal the discussedestuariesSpecialised These later salt in tolerantspecies Section or occur 5 halophytic with in particular distinct plant community reference species haveto types the colonised study of submerged region the intertidalin thismacrophyte study. and supratidal beds, inter areas and of supratidal salt marshes as well as reed and sedge areas. These community types function not only as 14 largeimportant number filters of ofinvertebrate sediment, pollutantsand fish species and barriers (Hennessey against 1994). floods, but also form an essential habitat for a 3.3.1Submerged Submerged macrophytes, macrophytes consisting either of Zostera, Potamogeton, Zanniche!Iia, Chara or Ruppia species arebare(Adams important softbottomed et al. for1999), juvenile habitats can supportfish and as marshesthey more provide diverse (Fredette protection and etabundant al. from 1990; predators,invertebrate Connolly as 1994). and well juvenile asThe providing submerged fish communities food macrophytes in than the form of important1999).the epiphytes Submerged for secondary that growmacrophytes onproduction these not plants. (Fredette only Theseserve et asplantsal. a1990). habitat also A serve forsubmerged juvenile to oxygenate fishesmacrophyte and the invertebratewater bed (140(Adams ha) fauna, etin al.the but lower are macrophyteindividuals.m2Chesapeake bed Bay (Fredette and was only shown et 13 al. ofto 1990). thesupport macrofaunal Furthermore, 75 resident species itmacrofaunal was could predicted produce species that 60.7 the with samemetric densities 140 t dry ha of tissue, submerged12 000 representing to 70 000 unknown.forapproximately consumption The 60possibility by billion higher individuals of trophic such productive levels. (Fredette The macrophyte etproportion al. 1990). ofbeds These this in estimation Southwould Africanthen that be isestuaries a actually potential isconsumed sourceunlikely, available butis the (Coetzeeexample3.3.2 SaIt given1995). marshes illustrates the function of submerged macrophytes in the secondary production of an estuary estuaries,estimatedSalt marshes i.e.that occurLangebaan the marshes only in Lagoon, certain cover approximately estuariesKnysna Lagoon, and 17embayments Swartkops000 ha, with along River, more the Berg than South River75% African ofand this Olifants coast. area confined River (Adams to five et lt has been theal.1990). 1999). nutrient Although Salt is releasedmarshes estuarine intoare theimportant water water levels column,inorganic and theif aand marshdegree organic is of rarely flushingnutrient flooded aresources important its importance for estuaries in determining in the(Childers ecosystem how and much Day of fordoesdecreases juvenile not decrease.fish (Childers species In and thanthe Day Mira the 1990). seaEstuary, grass The Portugal, bedsimportance in the the estuary assalt a marsh-waterhabitat (Costa for et invertebrate al.column 1994). ecotone The and primarybird was species, more production important however, of 602remainderSpartina g.2.yr maritima is either (Curtis) deposited Fenald, in the in estuary the Swartkops or washed Estuary, out to hassea been(Day estimated1981). Kokkinn at over and 10 Allanson 000 kJ.m2.yr1 (1985) or 1 (Pierce 1983). Only half of this is estimated to accumulate in the detritus chain and the Thisorganismsshowed suggests that that thatthe Jive importthe thereorganic of ororganic alternativelycarbon carbon produced itfrom remains bymarine the bound marshes sources in the isremains foodsubstantially chain. in the estuaryhigher than and thoseis utilised exported. by the 15 3.3.3The reed Reeds and and sedge sedges plant community types are found in freshwater and brackish zones of estuaries, usually theregionsas emergent water (Adams column. plants et Theyal. lining 1999). act the as Reedbanks. nutrient and The sinkssedge plants in beds the are natural arerooted capable environmentin the of soft removing substrata and are large ofso either amountseffective intertidal ofthat nutrients they or subtidal are from lotsReedsused of for nutrient,and water sedges purification or freshwater, can also in actartificial runoff as indicators intowastewater the estuary. of eutrophication treatment A change systems from in the riparian(Brix species 1993; land, composition Martin very lushand Fernandezfromgrowth salt indicating marshes 1992). estuarine(Cay.)to more Steud. brackish lake contributed (Taylor sedge/reed 1983). approximately species can 90% be theto the result total of littoral high nutrientprimary inputproduction (Brix 1993). of the Swartvlei,Phragmites a brackishaustralis 3.3.4provideMangroves Mangroves a food have source been or identified habitat foras numerousbeing important organisms, to the but maintenance are also a valuableof estuarine food, function. provide Mangroves timber and are economicallythe(Mugilidae). reason for important fisheriesSnedaker nearshorein (1978) parts ofestimated thespecies world. suchthat Mangrove upwards as snappers swamps of 90% (Lutjanidae), ofserve nearshore as vitaljacks marine nursery (Carangidae) species grounds wereand for mullets thefound in the success.regionsmangroves depends during as much one or on more the mangrove parts of their habitats life cycles. themselves, The success rather thanof nearshore the detrital fisheries foods forin manyrecruitment tropical 3.4Due ESTUARINE to the increasing IMPORTANCE number of RATING people utilisingINDICES the coastline (Allanson 1992; Begg 1978), there is now a theandneed environmental management to evaluate mustwater estuarine take needs. place.and This coastal The requires National resources biological Water and Actandto determine 1998 physical has informationsensitivealso identified areas to bethe where presented need careful to incorporate in planning an easily asBooksreadable a large (CSIR, and amount understandableEstuaries of time of is the required format.Cape Reportfor Comprehensive the Series)reading and and reports Estuaries interpretation summarising of Natal of the Report the information information, (Begg 1984),in order like arethe to determinedauntingGreen questiondevelopthe health, an (Ramm importanceindex 1988).which or givesPlanners, sensitivity an indication developers, of an estuary. of the managers status A simple of and certain way conservationists to aspects summarise of the biologicalcan area then or community seeinformation at a glance in is to areprioritisationwhich at riskareas to ofarebe sensitive identifiedsensitive areas (Turpieand requireis foremostet al. more 1999). in attention the implementation and which haveof the a Water high conservation Act and requires priority. estuaries This that 16 numberscoreOne way for of theto other achieve estuary. factors this The which is choiceto develop are ofalso a amulti- important method or single that in the summarises criteria estuary, index not the isjust biological important, the factor information used to obtain into an the index index or considering that there are a eachthe(Turpie aspects other, 1994). insteadwhich The are useof justimportant of indicesone, is in asacrifices anway estuary to achieve detail (Ramm for a morethe 1988). sake holistic Using of perspective, impression a number ofasof the indicesno conditionindex in canconjunction of summarise an estuary. with all Also,ratingbe determinedprovided developed the (Turpie details by Turpie etare al. etavailable 1999). al. (1999) This showing in is orderthe how concept to anprioritize index behind isestuaries obtained, the development for specific the implementation managementof the estuary of options importancethe RDM can achieveimportanceapproach a offinal rating the estuary National forms importance part) Water and Act. sensitivity rating Physical (Turpie to factors, future et al. threats biological 1999). of Arguments the characteristics estuary for are the taken(of use which ofinto certain theconsideration botanical components to in discussedtheO'Callaghan estuarine in detail importance (1990a, in Section 1990b) rating 4. developedhas been used the only in the other refinement botanical of ratingthe botanical method importance for estuaries. rating Past and present and is shrub,action,aerial photographs duneof the vegetation) False wereBay andestuaries.used water to observe surfaceThe increase the area changes were or decrease used in the to plant incalculate key cover vegetation the as relativea result types environmentalof (wetlands,industrial or riverine importanceresidential hadFalse(I), the changed Bay relative estuaries. as environmental a result The of conservability the state surrounding (E), the of an coefficientdevelopment. estuary wasof change Nocalculated change, (A) and by or determiningthean increaseconservability howin wetland much (C) of that oreach water estuary of the an(O'Callaghanarea, estuary was seen would I 990a, as receive a positive i 990b). a low effectA conservabilitydecrease and such in overall an rating. estuary wetland Estuaries would or receivewaterwith area a high was regarded as negative and such the highest conservability were Rooiels, conservability rating Zeekoeivegetation.Steenbras obtained and Residential, Buffelsthe lowest (Oos), recreational conservability due to andvery ratingindustrial little residentialdue developmentto the andpresence industrial as ofwell sewage developmentas alien ponds plant andaround encroachment, encroaching them. The werealien all (O'CallaghangivenThe examination as the major1 990a, of factors past 1 990b). and causing present changes aerial photographsto the vegetation can observedbe valuable in thesein determining False Bay the estuaries effects of estuariesdevelopeddevelopment only. in onthis The the project. interpretationestuarine O'Callaghan's environment of the aerial(1990a, and photographs has 1990b) been study, incorporated can however, be subjective, into was the restricted ashabitat it is necessary integrity to False index Bayto determine thepositiveFor extent this impacts.studyto which (O'Callaghan a development I 990b) has an had expert either panel a positive was used or negative to provide influence their opinions on the plantson both or negative estuary. and 17 implementationcommunityRamm (1988) to thedeveloped of communityhis CDI the no communitythatsubjective would decisionsexistdegradation in the are absence index made (CDI) withof (or respectto prior compare to) to degradation...."the "...the sensitivity present of biologicalparticular species In the theplanningto a estuarine pollutant purposes. healthor mix Cooper of Natalpollutants. et estuaries al. (1993) The andsubjectivity and west Harrison and is southin et the al. westerniterpretation(1994) used Cape andthe estuaries CDIin the (Ramm use respectively. of 1988)the index to The calculate for healthbiological index health, (EH I)water for different quality andestuaries. aesthetic conditions of the estuariesBiological were Health used toIndex compile (BHI) a final estuarine onThishistorical the index same was (potential) estuary. calculated Thecommunity afterCDI (Rammsurveying and the 1988) theactual existingwas community adapted fish communities to found measure in a survey.theand degree comparing of similarity them to betweenhistorical thedata Selected chemical and bacteriological parameters were used to obtainWater an index quality number index for the water quality nitrate,of an estuary. phosphate The andparameters chlorophyll-a used concentration.were dissolved oxygen, oxygenAesthetic absorbed, health ammonia, index E. coli counts, weretakenThis aspectnatural, into account took persistent into to accountdetermine odours, the thepresence appearance difference of exotic ofwere an vegetation, estuaryfloodplain by landuse,oilcomparison sheen, degree mouth with to itsstabilisation, wrich pristine channel state. presence margins Parameters of bridgesTheAn EHI final isand value derived degree obtained, from of visualthree for thecomponents,impact EHI, from is more industrial namely, representative ora biological residential of health,the buildings. overall water condition quality andof the aesthetics estuary thanindex. if only oneinformation.fairly of extensive the indices Should format had changes andbeen in used. suchhave aoccurred format that in the adequate data being comparisons used to develop can be themade index, with itpresent-day must be clear that If an index is used that considers historical data, the data have to exist in Thesuchconservation deviation changes from management. were perceived as a result referenceAn ofindication anthropogenic state of or the condition extenthabitat that degradationof South an estuary African and has estuariesnot been natural altered could causes bybe human(Rammvaluable impacts 1988). for classified.benchmarkcan then be One for compared managementway to addressto its referenceobjectives. this requirement condition. The National is The to classify referenceWater Actestuaries conservationstates accordingthat water condition toresources their can conservation be must used be as status. a 18 A number of human impacts affect the habitat integrity of estuaries. These include physical habitat destruction,assessmentIn order to improve watercriteria quality the have accuracy impacts,been selected and modification confidence and weightings of levels the flow of were estuaryregime given andhabitat to over-exploitationeach assessments, of the criteria. ofthe the Each above natural of the biota. criteria Thefollowsis then Swartkops giventhat of a Kleynhans score,Estuary which near (1996) isPort combined described Elizabeth into forhas a rivers, singlebeen and selectedrepresentative has been as a dulycase score adapted study for estuaries.for for the South implementation This African procedure estuaries. of the integrityspeculation.habitat assessment and Highwas givenflow procedure. modification the largest Despite weight.probably the Tidal standardisation, has flow the greatestand low the flowsingle procedure modification effect on is stillSouth that, based inAfrican turn, on afollowedestuary degree habitat byof the wasotherequally unknown listed rated, impacts althoughwhat theirfollowed it properwas this.conceived weights The tidal shouldthat flow their be.and impacts Likewise, low flow are modificationsthe probably weighting of less wereof allimportance given the thansame tidal weights, and low for it the other impacts were expertweightingsflows. opinion, could but then no beactual adjusted scientific for otherfield measurements. types of estuaries. Confidence This assessment inlt wasfinal hopedscore required wasthat literaturedependentfuture experience study on and would lead to more appropriate weighting of the impacts. The available3.5 PAST information SCIENTIFIC and knowledgeINFORMATION of an PUBLISHEDestuary (van DrielON TRANSKEI pers. comm.). AND CISKEI ESTUARIES availableThere is little for onlypublished twelve information of the seventy available six estuaries. on specific Some estuaries of the previouswithin the research study region. included, Publications physico- are communitiesMcGwynnechemical properties 1992; (Blaber Robertson (Read 1974; 1982, van 1996), der 1983, Elst zooplankton 1 1978; 985a, Whitfield 1 (Connell985b; Grobbler1979; 1974; Marais Wooldridgeet al. and 1987), Prinsloo 1974,crustacea 1980;1977) (Emmerson Plumsteadand fish and1984, the1990; mangroveTranskei Plumstead estuaries forests et found al.concentrated 1989a, in seventeen 1989b, on the 1991) of distributionthe ofTranskei the estuaries (Ward estuaries and (Whitfield Steinke(Muir 1937; 2000). 1982) West Previous and 1944; species botanical MacNae composition research1963; of in WhitfieldMolICiskei et and(2000)al. 1971; Transkei in hisBranch reportin terms and on Grindleyofthe mouth literature 1979). status, available biogeographical on South African region estuariesand condition. classified The Ciskeithose ofestuaries the are andopen.predominately upper The catchment.condition temporarily of Theeach openCiskei estuary with estuaries wasonly basedthe were Great on all theFishassessed degree and Keiskamma asof anthropogenicbeing in Estuariesa good influence condition, classified within i.e. as no thepermanently major estuary classifiednegativeEstuary anthropogenic asthat temporarily was assessed impactsopen. as Sixteen inbeing either inestuaries thea poor estuary condition. were or permanently catchment. The Transkei Anopen exception estuaries and one was waswere the a predominately river Keiskamma mouth 19 biogeographicexcellent(Whitfield to2000). poor. region, Conditions Forty the five remaining ofof thethese sixty-one sixteen estuaries estuariesfall vary in the more foundwarm than temperatein thethose Transkei found region. inare the found Ciskei in theregion, subtropical ranging from The3.5.1 Durban-based Physical environment East Coast programme and geomorphology of the CSIR has developed the Estuarine Health Index which, alongqualitybased the onindex aentire physical and South an classificationaesthetic African coastline.or naturalness scheme, Forty incorporates index. eight ofThe the an objective east index coast of of biological thatestuaries programme health from usingOld was Woman's tofishes, study a to estuarieswater the regionGreat1999a; Kei(Harrison 1999b).were sampled et al. 1 997a; during I 997b).1997. TheseForty three included estuaries the seventeen were surveyed estuaries in the found Transkei in the (Harrison former Ciskei et al. geomorphologytempeÊateThe Transkei and region subtropicaloccurs is uniquefrom biogeographic low-lying for three areas reasons. regions in the Firstly, alongsouth theitto is steep, eastsituated coast deeply in ofthe incisedAfrica. transition Secondly,river zonevalleys betweena changein the north.the in warm marshtheThirdly, South community the African Transkei coast.types region inThese the receives south three towards approximatelyfactors aremangrove assumed 200 forest- 300 to create mmin the more north.a transition rain than between any other the southern more xeric part salt of identifyingWhitfield3.5.2 Estuarine (1992) this single developed classification characteristic, an estuarine - a a geomorphologic number classification of physical system approach processes based couldon mouth be summarised. condition of estuaries.Five different In inestuarinetypes keeping were bays. theidentified mouth For example, namely:open. The temporarilypermanently open mouth open/closed, open allows estuaries tidal permanently inundation have a large open,to occur mean river within annual mouths, the runoff estuary. estuarine that However,is lakes important and the asGeomorphologicalrange in the of estuariesWhitfield classificationinclassification South Africa system,of is estuaries such but that it not describesa varietyonly tries of estuaries, environmentalto summarise as they theconditions should physical be exist conditionsunder in differentnatural of estuaries conditions systems. availableallows(Harrison for habitat etthe al. further 1999a; in terms subdivision 1999b). of floodplain Geomorphological of the width, five 'Whitfield' channel classification size,groups. mouth This not barrier subdivision only morphology,includes was mouth intended climate condition, toand identify catchment but also surveyandsize 5(Harrison43 estuarine Transkei et classes al.estuaries 1997a; were and 1997b). established 7 classes Harrison were(Table et established al. 3.2), (1997a; while (Table 1997b)Harrison 3.3). surveyed et al. (1999a; 16 estuaries 1999b) inwere the ableCiskei to region 20 Table 3.2: The classification of estuaries compiled by Harrison et al. (1 997a; i 997b) estuaries. The Whitfield estuarine classification is also shown. for 16 of the Ciskei lA Estuary class TemporarilyWhitfield class FrequentlyHarrison class closed Moderately(ha)Size Long wide Barrier type near(g.1)Salinity marine, Mpekweni, Estuaries open/closed smallModerately 9 - 25 Longbarriers wide nearwhendominatedoverwash marine, closed OldMtana,Gqutywa,Mgwalana,Mtati, Woman's, Kiwane Bira, i B open/closedTemporarily Frequently closed\ small 5 12 -barriers whendominatedoverwash closed Great Fish, 23 openNotPermanently considered openSmallNear permanently dry river 40SmallLarge 150 <5 Long ORange - 50-35 of Thatshana,TyolomnqaKeiskamma,Fresh Water 4 Temporarilyestuarine freshwaterFreshwaterchannelsbeds or Small 5 Perched 5 - 11 NgculuraShweleKrans,Poort, BlueShwele- Table 3.3: The classification of estuaries derived by Harrison et aI. closed(1 999a; I 999b) for 43 of the Transkei estuaries. The Whitfield estuarine classification is also shown. channelsdominated tideabove level neap IAEstuary class open/closedTemporarilyWhitfield class TemporarilyHarrison classopen smallModerately(ha)Size <5 brackishfreshVary(gSalinity fromor (1) barrierPerched Barrier type Mpenzu,Zalu,Ngogwane,Estuaries Ngadla, Kwa-Suka, Ncizele, Ku- 0.03 - 11 Sinangwana,Thsani,Sundwana,Mtumbane,Gxwaleni, Nenga, Bulolo, Ntlupeni, 21 B Temporarilyopen/closed TemporarilyopenNear permanently open smallModerately 5 - 15 O -16 35 18 -Perched Jujura,Gxara,Butsha Mapuzi Qolora Cebe, open/closed small 5 15 barrier MtentwanaMgwetyana,Mpande,Ntlonyane,Ngqwara, Mgwegwe, Ku-Bhula, Nkanya, 3A openPermanently openNear permanently >15 OgradientAxial - 36 * Qora,4),Mntafufu,Mdumbi,Kobonqaba Ngqusi/lnxaxo, Shixini, Mngazi, Mzamba Xora,(Plate 3C3B openPermanently openNear permanently 25250 Axialogradient - 36 - MsikabaMngazana and Mtentu 4 openopenmouthPermanently or River openRiver dominated 50 gradient<2range,Small0-36 km tidal - MzimvubuMbashe,Kei. Mtata, and Great 21 3.6 MANGROVES 3.6.1asProbably the Introduction mangrove no other forests distinct have. plant Rouetcommunity (1981) has in attracteda bibliography as much lists curiosity 5 608 published and scientific titles attentionup until 1975 for as with long anchoredone(Dugan of the in1993).first deep, being Mangroves black, the writtenfoul-smelling are account perceived mud, from as with the a jagged verdantchronicle forest crowns of Nearchus, protruding (Klause a fromet Greek al. the 1996). mariner surface Mangroves, circa of the 325 sea, estimatedBC roots ofHowever,to acover variety an over ofarea human the of past22 activities, million several ha, suchdecades, dominate as over-harvesting, the the global majority area of freshwaterin the mangroves world's diversion subtropical has increasingly and and conversion tropical diminished coastlines.to other as uses a result andsalt-tolerantsuch estuaries. as shrimp tree Mangrove or and prawn other pondstrees plant have (Snedakerspecies specially that 1993). thrive adapted Mangrove in intertidal aerial forestsand zones salt-filtering are of shelteredcomprised roots shores, ofand taxonomically salt-excreting overwash islandsdiverse, leaves thatleavesMangrove enable and branchesthem forests to occupyare from vital the the for mangroves, saline healthy wetlands coastal provides where ecosystems. nutrients other plant forThe the lifeforest marine cannot detritus, environment survive consisting (Dugan and mainly1993). supports of fallen theimmense mangroveplanktonic varieties ecosystem,and epiphytic of sea in life algaladdition ¡n foodintricate to chains. detritus food Plankton webs(Dugan associated 1993).and benthic directly algae through are primary detritus sources or indirectly of carbon through in withjuvenileThe shallowocypodids, fish, inter-tidalcrabs, cômprise shrimps, reaches a large and that proportionmolluscs. characterize In of both the the intertidaltemperate mangrove macrofauna. and wetlands tropical offerAs estuaries, detritivores refuge sesarmidand they nursery form crabs groundsan together for production(Snedakerimportant of link 1978).organic between matter primary as leaf producers litter that andenters predators. estuarine Energy systems flow and in mangrovesforms part of is abased complex largely food on web the mangrove)guttata,In the S.Mngazana Ionleaves gipes by Estuary and the S.detritivorous meinertifive species (Branch Sesarma of Sesarma and meinerti Grindley have was been1979). measured recorded, Consumption in includingthe laboratory of Avicennia S. catenata, and marina compared S. eulimene, (white to S. foundcorrelationfield between observations existed crab insize between the and Mngazana assimilation crab size Estuary and efficiency. the (Emmerson amount Seasonal of andleaf trendsMcGwynnelitter consumed in leaf 1992). litter per fallAlthough day, were no evident correlationa significant with wasa accountingandmean mean annual crab for 43.5% sizerate of of 40g,1.79 the leafg.m2.d1leaf consumptionlitter (653.4fall (Emmerson g.m2.y1). was calculated and With McGwynne mean at 0.78 crab g.m2.d1 1992). densities For dry estimated the mass entire (284.7 atmangrove 4 g.m2.y1),individuals.m2 area of 150 ha (Ward and Steinke 1982) and with a mean biomass of 4 g.m2, the Mngazana Estuary supports a S. 22 throughoutmeinerti population the forest, of of6 millionwhich 427crabs t dry(240 mass t fresh are mass). eaten directlyAn annual by S.total meinerti, of 980 tproducing dry mass 75of t leaves absciseof frasse. This meinerticontributesMangroves (7 990a considerableare million also kJ)prime (Emmerson amount nesting to and theand migratorydetrital McGwynne pool sites of 1992). thefor hundredsestuary. The of bird balance species. is In Belize, assimilated by S. for example, (Duganmonkeys,there are 1993). overfishing 500 cats, species monitor of birds lizards, recorded sea turtles, in mangrove and mudskipper areas. Additionally, fish utilise themanatees, mangrove crab-eating communities 3.6.2These The complex ecology ecosystems of mangroves are found between the latitudes of 32° N and 38° S, along the tropical coasts of Africa,54mangrove - 75Australia, species plant. Asia, (Tomlinson According and the to1986; Americas. two Fieldscientific There1995). studies, are The varying greatest mangroves scientific diversity classifications of mangrove ofspecies what exists in include approximately 16 -24 families and constitutes a Southeast Asia.Mangrovemangroves For example, forests exist alongthere literally portionsare live only in oftwelvetwo the worlds coasts mangrove at ofonce, the species southernacting inas the the New interface World between and only land four and species sea. USA. Mangrovesof stabilizingofhelp immense protect land importance.coastlines elevation from Theyby sedimenterosion, prevent storm accretionshoreline damage, thaterosion balancesand by wave acting sediment action. as buffers The loss. stability andImportant catch that coralalluvialmangroves reefs materials, and provide is thus Aseagrass primaryOther shorter-term bedsfactor are of alsothe factors natural protected are environment air from temperature, damaging that affects siltationsalinity, mangroves (Snedakerocean currents, over the storms, long term shore is slopesea 1993). and soillevel fluctuations. conditionssubstrate.(Snedaker Mostare 1978). optimal, mangroves mangroves live on canmuddy flourish soils, far but inland, they also along grow the onupper sand, reaches peat, andof coastal coral rock. estuaries If tidal suchrootsMangroves asof someAvicennia, vary mangrove in heightcontain species, according many smallsuch to speciesas"breathing" Rhizophora and pores,environment, or "red called mangrove", lenticels. from mere Theseand shrubs the allow pneumatophores to 40oxygen m trees. The prop to diffuse into of others, haveThethe plant, lenticels produced and are down some inactive to astounding the during underground high biological tide. roots Evolutionary characteristics by means adjustments of withinair space mangrove totissue varying inplant the coastal communities.cortex marine termed environments aerenchyma.Certain intheirspecies filtering leaves, of outmangroves roots salt thator branches. excludea thirsty salttravelerIn salt-excluding from could their systems,drink mangrove fresh others water species, actually from athe cutexcrete mangrove root, thealthough salt root that systemthe they tree absorbis so viaeffectiveitself stands in saline soil (Berjak et al. 1986). 23 developedadaptations.Certain mangrove seedlings, Through species which viviparity, maycan propagatetake embryo root germinationin successfully the soil beneath. begins in a marine onViviparity the environment tree may itself; have the because evolved tree later of as specialdrops an adaptive its tree,environmentmechanism thus accumulating (Steinke to prepare 1995). the the carbohydrates Duringseedlings this for viviparous long-distanceand other development, compounds dipersal, requiredtheand propagules survival for later and are autonomousgrowth nourished within ongrowth. a harshthe parent The saline al.seedlingsstructural 1986). complexityAnotherto extreme special achievedphysical adaptation conditionsby the seedlingsis the which dispersal otherwiseat this of early certain might stage mangrovespreclude of plant normal development propagules seed germination whichhelps acclimatehang (Berjak from the the et tocarriedbranches a year, to ofdistantand mature still shorelines. remain trees. viable.These Depending Viviparityfall off andon and the eventually thespecies, long-lived take these root propagules propagules in the soil allow maysurrounding thesefloat for mangrove extendedthe parent species periods, tree or to are up disperseswampsWater circulation operatesover wide is at areasan many important (Steinke scales, variable 1982).from the in large-scale the ecology tidal of mangroves. dynamics to The the watersmall-scale circulation flows in around mangrove mangroveaindividual typical 5 rootscreekskm long and can creek pneumatophores. be asis about high as 7 d.50 WaterThe d. Freshwater residence is trapped timeinflow, in aof mangrove watervia surface in a creek. large and groundwaterswampThe residence comprising flow, time and many of water for fromfreshwaterevapotranspiration the ocean. from riverineHydrodynamic affect inflow water evaporates, trappingquality by can generating a leadsalinity to anoxicmaximum stagnation conditions zone and exists,aeration near isolating.the zones. bottom. theIn Bioturbation,the upstream dry season mangroves all the inprincipallyUnder the soilsusual by (Wolanski circumstances, crabs, facilitates and Chapell when groundwater there1996). is significant flow which freshwater ventilates inthe a mangrove-fringedsoils and help flush estuary, out the crossexcess river salts floatinghypersalinecirculation material conditions aggregates is upstream occur, floating when midstream mangrove significant aggregation seeds freshwater in the occurs inflowmiddle at is fallingof present the tides.channel and Generally, downstream at rising thetide. whennet However, movement evaporation if of Groundwaterenhancedgreatly exceeds only inflow in freshwater the ventilates dry season. inflow. the bottomThis As a may result, waters control the of recruitmentmangrove creeks zonationof floating and at mangrove destroysgeomorphological the seeds anoxic in time theconditions, swampscales. is ChapellwhileThere groundwater is 1996). a strong feedback outflow entrains between algae the water into the circulation sediment and and the removes sediment them dynamics. from the The system topography (Wolanski and and reducesscouringthe vegetation theeven tidal withoutgenerate asymmetry freshwater a tidal and asymmetry the runoff. natural Land of self-scouring the reclamation currents. effect, Asof mangrovea result,resulting mangrove swamps in siltation forcreeks ofhuman mangrove are development naturally channels self- (Wolanski and Chapell 1996). 24 muddyforestThe plants except coast generate spreadsfor a few small-scale all minutes through near turbulence,the slackmangroves high maintaining tide. without As a formingthe result, sediment thenatural fine in levees sedimentsuspension along from inthe the banks. riverstidally Theinundatedand the dependsdepositionreducing largely zoneswave on energyof theriverine availability and and can oceanic be of usedfine sediment sedimentas an environmentally areto infilI distinct. the swamp. The friendly, response Mangroves soft-engineering of mangroves are very option efficient to a seaalong in level muddy rise shoresaggregatesplankton to protect mucus that the settlefacilitate coast rapidly. fromthe flocculation erosion.This process, In ofshallow fine together sediment coastal with watersinhydrodynamic suspension. the detritus trappingThis from generates effects,mangrove huge, enables plants muddy, micro- and the appearfringingmangroves, tothe be mangrovesseagrass vital to the and encouragesmaintenance coral reefs the ofto recruitmentprawnexist in fisheries close of proximity.prawn (Wolanski larvae The and spawned water offshore. The mangroves Chapell 1996). circulation over the mud shoals 3.6.3lt is thought Mangrove that the distribution earliest mangrove species originated in the Indo-Malayan region. This may account for oceanuniquethe fact currents,floating that there propagules to areIndia far and more and East mangroveseeds, Africa, certain and species eastwardof these present early to the in mangrove this Americas. region species thanThese anywhere spread westward, else. Because borne by arrived in Central and South of their which(DuganAmerica once 1993). during existed Duringthe upperwhere that Cretaceous Panamatime, mangroves lies period today. spreadand Later, lower throughout sea Miocene currents the epoch, may Caribbean have between carried Sea 66 across andmangrove 23 an million open seeds yearsseaway to theago Africawestern containand coast the aofAmericas much Africa fuller and contain rangeas far fewer, ofsouth mangrove but as similarNew species Zealand. colonizing (Bryant This species, might1998). explain whereas why those the ofmangroves Asia, India of and West East and3.6.3.1Mangroves Steinke Mangrove extend 1982). swamps formIn the the Kosi along Kosi system systemthe east six (26°S) coastmangroves ofin theSouth northare Africa present: to the Nahoon Avicennia River marina (Forrsk.) Vierh. (33°S) in the south (Ward (White Acrostichumracemosamangrove), Willd.aureum Bruguiera (Kosi L. (mangrove gymnorrhizamangrove). fern), The (L.) CeriopslatterLam. two(black tagal species mangrove), Perr. do C notB RobinsonRhizophora occur further (tagal mucronata mangrove) Lam. and (red Lumnitzera mangrove), south except as transplanted existencemarinamaterial is in commonof the this Beachwood species up until is areathethreatened Kobonqaba of the Mgeniby periodic Estuary Estuary. floods whilst In theand further estuaries predatory south of thissesarmid the species southern crabs occurs Transkei that sporadically.limit the spread The Avicennia andatfurther Wavecrest reaches south. its (NxaxoBruguiera southern Estuary). gymnorrhiza limit at Rhizophora the Bulungula is sparse mucronata, River.south ofAcrostichum whichthe Mbashe is common aureum Estuary as the farand mangrove south its natural as thefern distribution Mtata extends Estuary intoends Pondoland (northern Transkei regions). The freshwater mangrove Hibiscus tiliaceus, which is a frequent 25 toassociate the Nahoon of mangroves, River. is common to Mbashe Estuary, whereafter it may be found further south sporadically ofdistributionMacNae mangroves, (1963) of mangroves that suggested mangroves along that onlytemperature the occurSouth where African was the coast. meanmost-important He annual proposed, temperature limiting based factor on does the of not thethen dropsouthward known below distribution 19°C. Zealand,TheHowever, southernmost as growthfar south distribution of asAvicennia the 38°S of marinaAvicennia (Clarke to and maturitymarina Hannon isoccurs found 1967). under at the muchNahoon colder Estuary, conditions owing in to Australia the transplanting and New competitiondistributionof propagules offrom propagulesfrom salt Durban marsh (Steinke Bay, species. although 1982). Bruguiera itA. is marina possible gymnorrhiza seedlings that a standhas show grown further vigorous to upstreamthe growth, heights did evenof arise 3 min fromtothe 4 face mthe within naturalof thedistribution.sheltered paucity, regions Researchlongevity of the and in NahoonSouth limited Africa Estuary.dispersal and ThisAustralia of range suggests hasof propagules shownthat temperature that (Steinke the distribution is 1982;not a Clarkelimiting of mangroves 1984).factor ofIn is mangrovea limited by buoyantPropagulespreliminary on studysheddingwere shownSteinke their to experimented pericarp.be either Whilesinkers with the i.e.Avicennia different sink on marina propagulesshedding propagules their showed pericarp, from large differentor variations floaters, estuaries. i.e.in buoyancy remain of highcolderfloaters, density. climate those However, (warmfrom the temperate samplessouth produced regionobtained of mainly thefrom Transkei) the'sinkers'. Kobonqaba in The the differencesouth River being in 1978,was responsible assumed 1981 and forto 1983 bethe climatic, propagules had a higher with of the suggestedpercentagelt is probable that of that 'floaters' drought mangroves thanperiods surrounding found and inresultant the estuaries southern increases showingTranskei in salinity that(Mbashe this within was Estuary these not always estuariesto Nahoon the were case. Estuary) likely Steinke thatcauses. further elsewhere.behaviour,produce aIn highit the is suggestedproportionabsence of thatof evidence sinking estuaries propagules, for suchthe involvement as thewill Mbashe,contribute of environmental where little propogative almost factors all propagules material in determining for are distribution sinkers, buoyancy there establishmentestuary.would appear In that towould case be little therenot propogativefollow is cause easily for materialon concern destruction from for thefresh of futurethese sources ofmangroves these entering mangrove (Steinke and becoming communities, 1986). established because in re-that 3.6.3.2otherIn addition gradients, Location to their namely;of geographical mangroves freshwater in spread, South input Africanmangroves and their estuaries positionare distributed along the within intertidal estuaries profile according (Duke 1992). to at least Since two the (Watsonregionmangroves i.e. 1928). six of versusSouth Africain excess exhibit of forty such species, low species complex diversity patterns compared of arrangement to mangroves are not found in evidence in the Indo-pacific here 26 downstream,Steinke (1995) intermediate has described and the upstream two gradients estuarine; with and each low, having mid andthree high different intertidal categories, profiles. including The physical categoriesconditions ascribedareto based 20 g to i on andthese salinity upstream gradients where approaches havedownstream not been fresh represents fully water. understood The values intertidal orapproaching quantified. categories 35Estuarine gare essentially location based on (I, intermediate 5 extent g e areasvariations,and frequency of estuaries, e.g., of Avicennia tidal while inundation. Rhizophora marina canThese mucronata occur categories in the is verymouth only restricted serve of upper as in guidelinesreaches and as inspecies the intertidal can show of supratidal its distribution within an estuary (Steinke marked Africa.within1995). estuaries, Table 3.4 while summarises Table 3.5 thesummarises distribution salinity of the and six mangroveinundation species tolerance along of mangroves the South Africanfound in coast South and Table 3.4: Distribution of mangroves along the South African coast and within estuaries (adapted from Steinke,Intertidal 1995). position; Key -H Estuarine = High; M location: = Mid; L D= =Low. Downstream; I = Intermediate; U = Upstream LumnitzeraAcrostichumMangroveBru guiera racemosa gymnorrhizaaureum SouthernWavecrestKosiPondolanddistribution Bay most (Nxaxo natural Estuary) 32°35'26°27'31°Latitude locationEstuarineD,I,U M,HHpositionIntertidal HibiscusAvicenniaRhizophoraCeriops tiiaceus tamarina gal mucronata GqunubeNahoonKosiNahoon Bay Estuary Estuary Estuary 32°59'32°56'32°08'26°54' D,II,UD,I,UD,I HL,M,HL,MM,H Table 3.5: Summary of mangroves species found along the South African coast with inundation and salinity tolerances as well as plant succession status. SpeciesGenusgymnorrhízaBruguiera and InundationsubmersionRoots better tolerances diebackadapted afterto periodic 4 - 5 Salinity15(g.e - 20 ranges 1) SeedlingsLateGeneral pioneer. prefer shade mucronataRhizophoraCeriops faga! FoundsubmersionIntolerantmonths on of ofhighsubmersion frequent ground periods flooded of only 515 16 - 20 NotmarginalinLate dense a pioneer pioneer. standscreeks. and Found along found racemosaLumnitzera highLowby high inundationground spring tides tolerance prefers marginsmangrovesoni.e.Prefers the Freshwater interior of landward mangroves, stands of input marinaAvicenniaaureumAcrostichum submersionSensitiveintolerant to of(4long frequent- 5 periods months) tidal of inundation 5 - 35 SeedlingsmangroveLandward15-20intolerant, g.e1 shade marginsoptimum of 27 The fauna and certain elements of the KwaZulu-Natal coast have been shown to have affinities with the alongAfricantropical shores eastIndo-West coast, exposed Pacific.the tocommunities the Studies open ocean.along show the tropicalThe coast mangroves affinities have indicated alongas opposed the that east withinto thecoast temperatesheltered can be dividedshores organisms ofinto the foundtwo South thegroups:arrangement Transkei The northerlycoast than down are group theto East northernfound London. along mangroves. theThe Natal/Mozambique southern Examples group of of the coastmangroves zonation and the ofare thesoutherly more southern typical group mangrove in found pattern along swamps and elevationareplants those and betweenfound that at of thezones. the mouth mangroves The of highest the influencedMngazana of the mangroves byEstuary the sea (31 zoneis o5O abrupt is S). characterised evenThe transitionthough by there betweensalt may marsh bethe plantslittle terrestrial change at the in approximatelyspringoccasional high water submersion; 25 cmmark. in verticalChenolea Stenotaphrum height. diffusa secundatum Thunb., occupies (Walt.) this O. metreKuntze, wide Sporobo/us zone, forming virginicus dense (L.) stands, Kunth. and lt is usually invaded from above by grasses that are tolerant of exclusivetowardsPaspalum the areas, sea.vaginatum withThis conspicuous zone Sw. is The followed first associates two by area zone morealong of conspicuous theJuncus upper kraussii edges and Hochst.,areSporobolus the grasses a sedge virginicus listed which above,extends occupies while furthest thestandsSamolus Avicennia are sparserporosus parkland. and Thunb. SarcocorniaStands is scatteréd of A. pillansiimarína throughout. occupybecomes theUnder more intertidal more evident. waterloggedflats, The with zone the conditions openthat follows areas the coveredhas Juncus been by kraussiitermed Cot u/a the1986).coronopifolia seaward The and mangroves L., landward Trig/ochin extend edges. striata down Rarely Ruiz to and theis there Pay,level more andof high Sarcocornia than water one neap row perennís oftides. A. marina Avicennia (Mill) treesA.J. marinaScott on the (Berjak is seaward the pioneeret al. edge on mucronataThisin thethicket Mngazana is is found.to reasonably Estuary. be moreopen Between prevalentand individual the alongtwo rangestrees channels, are of quiteAvicennia where tall, the some there water exceedingis ais thicketdeeper. 7 of m The Bruguiera in height.final zone gymnorrhiza.Rhizophora within the firmthemangrove steeplysand below swamps sloping the outerof low the watermark banksMngazana of meanders Ha/ophila is a stretch belowova/is of the the(R. submerged Br.)pneumatophores Hook f. macrophyte is found of the(MacNae Zostera Avicennia 1963). capensis marina Setchel. trees. On on

28 Plate 3.1: The Mngazana Estuary, the largest and most complex mangrove system along the Transkeicoast. Three mangrove species are present and cover approximately 145 ha. 29 3.6.4Naidoo Factors (1986, 1987,affecting 1990) the studied colonisation the possible and succession role of soils, of osmotic mangroves potentials and salinity in influencing the waslaboratory.establishment shown that Soil thereof samples different was anwere mangrove increase collected zonesin sand from in contentpurethe Beachwood stands in the of seaward Avicennia area on edge the marina Mgeniof the and EstuaryAvicennia Bruguiera and zone. ingymnorrhiza. the This was lt sandyoutattributed of suspension.substrates. to the turbulent Colonisation Avicennia and waschurning results also inidentifiedaction consolidation of tidalas the waters andpioneer stabilisation that species only permitted ofat theBeachwood substrate. the coarse and This, fraction is able in turn, to settlecolonise becomesalteredpermits sufficiently, established.the accretion not Theonly of finer particleby Avicennia particulate size distribution colonisation, matter such suggests but as alsosilt thatand through greaterclay. soilOnce deposition forming the nature processes, of finer of the sediments substrateBruguiera is is allowsofoccurring the Bruguiera water further to remain zoneaway is fromin probably the the swamp water's due for to edge. slowprolonged ratesThe higherofperiods. inundation proportion Most of of the theof fine.soilswamp silt and and fractionsclay to deposited the in low the slope surfacein the that swamp layers originatesimpededWolanski byand from the Chapell coastal friction (1996) riverscaused andidentified by the the offshore high that planttidal sea currentsdensity. areas. inThe mangrove currents forestêare complex, found incomprising the Florida eddies, region jetsare turbulencecohesive,and stagnation mainly created zones. clay by and theThe flowfine sediment silt,around and particles theform vegetation. large carried flocs. inThe Thesesuspension turbulent focs remainintensityinto the in forest issuspension largest during for tidalastrees a inundationresult forming of thea are thisfocscomplex sediment. settle matrix in the Hence, of forest roots the aroundsuch inundation as slack Rhizophora highof coastal tide. mangle Atmangrove ebb and tides smallest forests the water atfor tidal singlecurrents frequency trees are such too works smallas Ceriopsas to a re-suspendpump tagal. The correspondingsuspendedpreferentially sediment to transporting about brought 10-12 fine, inkg from ofcohesive sediment.m1 coastal sediment waters of creekat from spring length/springcoastal flood waters tide, tide,was to the resultingtrapped mangroves. inin thea rise mangroves, About of the 80% substrate of the banks,mangrovesabout 0.1 but cm.y1. actively (Wolanski The contribute selectiveand Chapell to trapping the 1996). creation of Mangrovesclay of mudwas bankscaused are thus(Wolanski by notflocculation just and opportunistic Chapell of the finer1996). trees particles colonising in the mud stronglyThe3.6.5 variety Vegetationinfluence of plant the habitats change habitats within with topographic tidala deltaic-estuarine flat formevolution of the regionhabitat, are the affected frequency by geomorphicwith which it processes is inundated which by mangroveformtides, of the mangroves sediment tidal flat developmentaretype, also the closely salinity has related ofbeen the proposedsoilto these water interacting withand the consequentdegree environmental of soil plant aeration. factors. colonisation Distribution A short-term and succession and model growth of of mangroves and associated vegetation (Thom et al. 1975). The short-term model covers erosion and 30 changesdeposition in tendenciesthe Ord River, for upNorthern to twenty Australia, years overcan bewhich divided changes into five can stages: be documented. Short-term model Depending on the velocity of tidalStage currents, i fine sediments are deposited forming small tidal flats not greater mflatsthan above with3 m MLSL.Avicenniain height above marina Mean mangrove Low Sea seedlings Levels being(MLSL). present, The grass particularly Sporobolus when virginicus the surface colonises the tidal rises to above 6 Dense Avicennia marina thicketsStage develop 2 rapidly on the recently emerged islands in the Ord channel over a monospecificperiod of 21 years community (1948 covers- 1969). the At midthis tidalstage, flats. the Surface flat is between sediments 6 and are 7 wet, m above dark in colour and MLSL and a is apparent that contain afterhigh levelsperiods of of organic mudflat detritus. progradation In theStage shortouter 3 periodsestuary, of where erosion wave occur. processes are effective, it inthe Intidal dominant this inundation, stage process. most with of Asthesites the tidal furthest tidal flats flat areaway rises fixed from toward in tidalposition. the channels mean Vertical high receiving accretion water less mark as tidal (MHWM),a result coverage. of theretidal is a sedimentationThis stage is is reduction taaccompanied gal). However, by the the invasion innermost of otherfringe mangroveof the mixed species mangrove that are community, tolerant of which shade locally (Bruguiera may be sp. internally Ceriopsis first evident,zoned, is and becoming Avicennia progressively and Ceriops Stagemore form open.4 a low At shrub these community dry, infrequently mixed withinundated Sarcocornia sites, die-back and Sporo ho/us. ofphenomenonThe the tidal soils flat is has aespecially feature now reached of in such those meansites areas and high inundated Sarcocornia water spring only may atmark the develop (MHWS).highest meadows spring At this tides. surroundingstage Hypersalinity dieback the is mangrovea (ca. 40 g frequent Avicenniaabovestumps. MHWS. -Bare Ceriops areas zones also alsodevelop undergo at this initial stage. dieback In the once outer the estuary sloping the flat inner attains margins an elevation of the Rhizophora at or slightly and Withmaximum the bulk extent. of tidal Mangroves, flat lying perched eitherStage atzoned 5 or above or mixed, MHWS, have the contracted bare high tidalto the surface margins at ofthis channels. stage reaches lt is as its though the retreat of plants from the rising flat has left a denuded surface in its wake. The salt marsh zone 31 tidalremains creeks relatively and gullies. constant in width and retreats with the mangrove. Small levees develop along the banks of Through3.6.6 Mangrove natural and vegetation man-made change events, inmangroves response along to f/dads, the northern cyclones Kwazulu-Natal and changes coast ¡n tidal have regime been (Breencyclonessubjected and and to Hill a alteration number 1969). Aof of period changes tidal regimes.of lowin the flow Thephysical resulted earliest environment. in account mouth closureof Processesmangrove of the lossincludeKosi is Estuary in physical the St following Lucia removal Estuary Cyclone due to of Claudethefive mangrovemonths and the(August species level 1965of inhabiting the -January estuary the was1966) lower raised until elevated bythe 1.6 mouth regions m. The was of mangrove breachedthe estuary. swampsartificially. The greatest were This inundated resulted dieback inwasfor dieback a thusperiod wereevidencedregenerated lost. in the (MolI Avicennia et al. 1971), marina but and it was Bruguiera estimated gymnorrhiza that it would stands be ain decade which almost before 90%the mangrove of the mangroves swampsIn 1971 most of the mangrove swamps had been recolonised and species previously present had wouldlow-levelA similar return scenariobridge to their in wasthe former upperseen state inreaches the (Bruton Mgobezeleni of the et al.estuary. 1975). lake-system The bridge at Sodwana, led to the butrestriction as result of oftidal the flow. construction Average of a foundsystem,salinity in for andthis this foundlake-system. part itof to the have estuariesHowever, the largest was faunal treesmeasured species (all> 10 atrecorded 0.3m) andg.(1. insuggested MacNae his survey (1963) that had this disappearedhad was also due surveyed to and the hadlow this beensalinity ofreplacedA furtherthe bridge, consequenceby freshwater resulting in ofspecies thisthe constantbridge (mainly was low molluscs). the salinity backflooding found Bruton in of(1980)the the system, Bruguiera further further indicated gymnorrhiza species that woulddue mangroves to be the replaced. construction found in Attemptshasthe upperonly of led alleviatingreaches to partial of the the recovery problemestuary of whichof the poor mangroves. were tidal then flow inundatedltwere is also made estimated for by a reconstructingperiod that of complete four months the recoverybridge. (Bruton However, of 1980).the mangrove this swampsinThe the cyclones estuary would Domoinamade occur it after possible and a lmboadecade to establish struck (Bruton the the et St al.effects Lucia 1975). areaof these in 1984. cyclones Research (Steinke at that and time Ward on 1989). the mangroves The heavy heighttherains inundation that showed accompanied ofthat the B. mangrove gymnorrhiza the cyclones stands suffered and resulted the the subsequent greatestin mortality. mortality flooding Total (32.9%ofcounts rivers ofdead) raised trees followed lakegreater levels by than A. (1.5 onemarina - 2.5metre (16.2%m) inand impactlongdead) term. after of floodwaters The four immediate months or ofon effectselevated the substrate. comprised lake water Long-term the levels. breakage, effects The effects uprooting on the of mangroves the and cyclones collapse were were of seentrees both incaused immediatethe form by ofthe and lowered propagative material produced for the first two seasons after the cyclones (1985/86). There was a 32 further delayed effect on the mangroves that were manifested eight months after the floods. The trees showedandcompacted disturbance signs andof stress formedof soil and root hard leaf water impervious loss relations, as a result crusts. resulting of theThis fine inpossibly the fluvial visible resultedsediments stress in and reductionthat death retained inof soiltrees. moisture, gaseous but later Five years after exchange ofthe3.6.7 mangroves flood, Importance recovery as stabilisers andof the function mangroves of highly of mangroves dynamichad occurred, coasts with (Steinke little damageand Ward evident. 1989). This further underlies the role tropicalforests.Throughout forest.Mangroves, the Moreover, world being there the intertidalis importancea general forests, realisation of theare mangroves no about exception. the is ecological not Their merely value and in as itseconomic forestsforest value,is importance no lessbut itthan is any of the due to its strategic1993).Mangroves location are betweenbuffers between the land the and land the andsea. the Mangroves sea. All shorelines are the lifeline are under for any the coastal constant area threat (Snedaker of erosion Thereestuaries,due to iswave a providingbelief action that andthem the tidal increasing with motions. some floodsprotection Mangrove in Bangladesh from plants these stabilise aretidal due bores, shorelines to loss ocean of andmangroves currents the banks and in stormtheof rivers past surges. few and Mangrovesdecadesphenomenon, and not there only since is help not there muchin preventing is adisagreement general soil tendency erosion, regarding of but water alsothis to viewreclaim engulf in the landland. scientific from Mangrove seas. community Thisforests is a(Chapman and very estuaries are unique 1984). theeconomicshrimp, breeding crab repercussions and and nursery fish species. grounds through Hence, for the a lossnumber loss of of the ofmangroves fishingmarine industry organisms not only (Blasco affectsincluding et usal. the indirectly1998) commercially but there are important direct appropriatelytimberIn many for countries building, it is possible of firewood Southeast to andderive Asia charcoal. timber and the productsExperience Pacific, from mangroves has mangrove shown are that forests used when commercially without these significantactivities for the are managed environmentalproduction of fisheriesdegradation,In many (Blasco coastal and etwhile areas al. 1998).maintaining mangroves their are valuea substitute as a nursery for fodder. and aThus, source mangroves of food for reduce commercial pressures capture from the scarceabilitystill exploited pasturelands. of mangroves in many Till has areas recently, become in India. mangroves a curse Mangrove for wereit since wood the in mainhas most a source highcoastal calorific of areas, value rural andor urban, burns very tannin for the leather industry and are communities are well. This Aboveinheavily West all, dependentBengal mangroves and on Orissa. mangroveare now The looked finestwood afterqualityfor fuel. by of scientistsHoney honey collection that as savioursfetches from a in goodmangrove today's price scenàrio areasis collected is of global from mangroves. practised exclusively warming. We all know that most of the coastal areas throughout the world are going to be affected by sea 33 level rise due beflooded,to globalour future mangroveswarming, resource the can (Bandaranayakeeffects possibly of which provide are 1998). a alreadygene bank visible. for cultivatingTherefore, salt when tolerant most speciesof the coastal of crops areas that will could be traditionally3.6.8Local populationsThe managed importance for mangrove the far/oca! production ecosystems communities of food, sustainably. medicines, tannins,For millions fuel ofwood, indigenous and construction coastal residents, materials have andThemangrove storms.protective Inforests mangroveregions offer where dependable,buffer these zone coastal helps basic minimisefringelivelihoods forests damage and have sustain of been property their cleared, traditionaland lossestremendous cultures of life problemsfrom (Bryant hurricanes 1998). of nitratestoerosion destructive and siltationphosphates, storms. have Mangroves therebyarisen, andpreventing have sometimes also beencontamination terrible useful lossesin oftreating nearshore to human effluent, waters lif.e as and the(Snedaker property plants absorb have1993). occurred excess due 3.6.9theyNaturally are Future now resilient, threatsbeing mangrove devastated and management forests by modern have withstood encroachments. severe stormsToday, andmangrove changing forests tides are for amongmany millennia, the most but attacksthethreatened exposed by parasites, habitats portions in andof the mangrove prolongedworld, disappearing roots flooding are highly from at an artificialsusceptible accelerating dikes to or cloggingrate, causeways yet withby crude little(Chapman oilpublic and notice.1984).other pollutants, LenticelsOver time, in al.haveenvironmental 1998). also severely stress impacted can kill mangrovelarge numbers forests, of mangrove as well as trees.tourism In andaddition, other the coastal charcoal developments and timber (Blasco industries et themangroves.The artificial rapidly expanding shrimpLiterally, ponds thousands shrimp of this aquaculture ofboom hectares and industry bust of lush industry. poses mangrove theThis gravest forestshighly threatvolatile have beento enterprise the cleared world's has toremaining makegrown room for exponentially"wastelands",Until recently, overormangrove useless the last forestsswamps. 15 years, have This leaving been erroneous classified devastating designation by manyruin in governments hasits wake made (Dugan it easier and 1993).industries to exploit alike mangrove as forests Philippines,destructionas cheap and ismangroves alarming.unprotected haveThailand sources declined has of lostlandfrom more andan estimated water than halffor shrimp 448of its 000 mangrove farming. ha in the The forests 1920s amount sinceto only of 1960. mangrove 110 000In the ha forest by 1990. Globally,mangroveIn Ecuador, as forested estimatesmuch as coastline. 50% of mangrove percent The Muisneof loss mangrove range region from destruction of 20%Ecuador to nearlyin alone recent one has years half lost of hasnearly Ecuador's been 90% due ofonce to its clear mangroves.362 cutting000 ha. for of shrimp farms (Bryant 1998). 34 3.6.10The failure Protecting of the national mangrove government forests to adequately regulate the shrimp industry, and the headlong rush of mangroveandmultilateral social forestscriteria, lending may areagencies othernow rest importantto fund in the aquaculture handspieces ofto the thisdevelopment consumers unfortunate without from puzzle the meeting (Duganwealthy their 1993).nations own The statedthat fate import ecological of remaining these theirmangrovesluxury coastal shrimp are resource products. necessary. base, Meanwhile, Also, including involvement stricter the nearby local of localgovernmentalmangrove communities forests, regulations inis sustainablyessential and (Bryantenforcement managing 1998). and protecting protecting

35 44.1 A INTRODUCTION BOTANICAL IMPORTANCE RATING SYSTEM FOR ESTUARIES AffairsincreasingThe need and to humanForestry classify demand (DWAF)and rate for onestuaries freshwater the need along forresources. rapid the South determinations Emphasis African coasthas of beenthe has conservation becomeplaced by necessary the status Department and due habitat to of Water theunderintegrity amount the of National an of estuarywater Water required which Act is byas considered thethey estuary. have potentiallya right to water. suitable The for ecological water abstraction. reserve has Estuaries to be determined are protected i.e. FishofThere the health estuarineare a index number plants (Harrison of (Coetzeeways et to al. assess et 1999a; al. 1996, estuary 1999b). 1997; importance The Riddin Fish 1999; healthand status.Colloty index These et(FHI) al. 2000), ratesare either an birds estuary based (Turpie based on 1995) the on status or its the influencecanfish communities,also bethe used, status wateras or an condition qualityindicator and of of all aestheticecosystem higher trophic qualities status levels. because(Harrison plants et al. 1999a;ar the primary 199gb). producers Botanical andimportance will wasA botanicaldefined revised as importance to the include contribution swamp rating ofwas forest, the developed estuarine mangroves, plantsby Coetzee macro- to the andet conservation al. microalgae. (1996, 1997). status Subsequently, Botanical of an estuary. importance the Thisconcept rating was of system functionalcontainsmultiplied importance a by large an averageor diversewas introduced, productivity number ofi.e. value. habitats the sumAn (Colloty estuary of the area etwill al. havecovered 1998). a high The by the functionmore different plant importance communityplant community score types if it typesin an BateestuaryEstuarine 1994). the management greater the number and conservation of interactions must that incorporate occur between the maintenance plants and otherof estuarine organisms habitat, (Adams and andprotect system,thenumber maximum criteria of species, variety that are ofbiological habitatrelated typestocommunities biodiversity (Riddin 1999).or must ecosystems also However be considered. (Bryant to assess 1998). Measuresthe Biodiversityconservation of biodiversity can importance also beinclude assessed of any the endemismspeciesthrough needthe (Myers description protection. 1990). of The Sevenspecies term botanical distribution"hot spot" 'hot has patterns. spots" been have usedAreas been to that describe identified contain regions high levels that contain of rare aor high endemic level of in South Africa, but they only Theincludebiodiversity, most terrestrialappropriate a large species waynumber to (Cowling protect of rare biodiversity andspecies Hilton-Taylor or wouldendemics. be1994, to However, conserve Hilton-Taylor thisall habitats is 1996). not possible that have and a highconservation efforts need to be prioritised in terms of areas that have high levels of conservation importance (Dugan 1993). 36 theTurpiemethod botanical et al. included (1999) importance aspectssuggested of ansuch thatestuary as the species shouldconservation richness, include importance the community following: of richnessan functional estuary and couldimportance, habitat be rarity. An determined if a rating species richness, assessment of (O'Callaghanspeciesplant community rarity 1990a,or endemism type 1990b). richness do notand apply habitat to estuarinerarity. Usual plants, measures as most of areconservation common or importance widespread. such as values(TurpieUse of multi-criteriacan1995), remain but ifmeaningful indicesthe separate have to beenthecomponents user. criticized The of value because an index should they or ratingalso hide communicate systemthe value are of kept thevalid individualtransparent, summaries components then ofthe final componentsbotanicalinformation importance (Hopkinson are then ofused etan al. toestuary 1978).interpret through the final the scoresummation or rate of an a estuarynumber withoutof components. loss of information. Each of lt is the intention of the revised botanical importance system to rate the these ecosystemtermsThe change synonymous exhibits in functional withintegrity integrity importance if, when include subjectedover habitat time tocan status disturbance, be usedand habitat as ita retains measure condition the of ability (Turpie botanical to etrecover al.habitat 1999). toward a state integrity. Other An time,thatintegrity is measured normal has for also from that been past system. used records Habitatto highlight or aerial integrity thephotos conservation has for been the determinedSwartkops importance Estuaryusing of estuaries the (Colloty change in et the in al. plantnorthern 2000). cover Eastern over Habitat Cape4.2 MATERIALS Province (Pondoland AND METHODS - Transkei) (Colloty et al. 1999). 4.2.1Themaps, area Assessment aerial (ha) covered photographs of areaby the from(Directorate different aerial plant photographs,Surveys community and Institute pasttypes literature was for Coastalmeasured and Resource field from surveys 1:50 000 topographic Management, University of topographicPackardPort Elizabeth) Scanner maps. and The 4C). published area The covered digital values. images by Verticalthe weredifferent aerial then plant photographsscaled community using wereknown types converted distances was measured into calculated digital using images from image (Hewlett- Africansmallestanalysis estuaries softwareaccurate was (analySISarea obtained that could3.0 from - ISAT). beRiddin measured The (1999) minimal on and aerial Walkerarea photographs. considered (pers. comm.), wasAvailable 0.1 who ha informationextended because thethis on application wasother the South of the33Coetzee botanical estuaries. et importanceal. (1997) summarised rating to estuaries information in regions contained where in littlethe CSIRor no Estuariesinformation of wasthe Capepreviously report available. series for 37 4.2.2 Application of the botanical importance rating formula TherarityBotanical botanical scores importance importance of each plant = ratingFunctional community is as importancefollows: type present. + Speciesrichness + Community richness + Sum of habitat countingthereAll the was component the a high importance degree scores criteria.of were correlation tested forbetween correlation any of with the the components existing functional there would importance be a risk index of double scores. If any correlations were found then that particular component could be left If componentsout.In order However, to sum could no the correlations be various retained. scores, were foundthey have between to be the normalised. different components Normalised (rO.05, used to n=179) reduce and the all sizepercentageby ofassigning scores ofand the that. simplifyestuary Each comparisonswithof the the components highest between score (i.e. estuaries.a speciesvalue of richness, The100. functionalAll other functional estuaries importance importance, were score then plant was expressed communitynormalised as a valuestypeinto richness smallerfor the anddifferentnumbers. plant components, community If raw data type scoresfor examplerarity) were was usedthe assigned St then Lucia one aEstuary set would of ranges had have a functionaltoto compareconvert importance the a wide raw datarange score scores of ofscore ca. and2 009Inc. the 023version ranges and 98). awere species A percentiledetermined richness (Galton using score a1885) ofpercentile 27 of(Fig. a distribution 4.1).test for All eachthe of score valuesof the ranges component is a number are from scores that zero indicates (Statistica to one thehundred - Statsoft theofpercentage Table percentiles 4.3). of Thevalues for scorethe between ranges data were coulda range not be normallyofskewed scores towardsdistributed that occur the (geometricin scores that percentile that distribution, occurred (see lessthe p<0.05, first frequently. and n=1 second 79) Using and column thusthe nearestnumberpercentiles, multipleof estuaries the numberof 5 thatto maintain ofoccurred estuaries the within skewedthat eachoccurred distribution percentile within of waseach scores, subtracted of the i.e. ranges 1 estuaryfrom could 100 had and be a determined.roundednormalised up functionaltoIn theturn, the componentsthisimportance range (>70.57) score of the >70.57 botanicalof normalised (Table importance 4.3). scores Therefore, ratingis 100 as (1 the shown00-1 final 99 infunctional rounded the example upimportance to (Table 100). Thisscore4.3). was Converting for doneany estuary for scores all the within into beenrangesNone usedof simplifies the in components the estuarinethe construction receive importance any of a further rating rating weightingformula (Turpie whileet in al. order retaining1999). to ensure information that the and botanical has consequently importance alsorating estuary.summationsystem This is objective isof possiblethe components. and as each the ofseparate the components components can bear contribute no relationship equally to to the each overall other importance and allow offor the the 38 4.2.2.1contributionFunctional Functional in importance the formimportance of was energy based input on (i.e.the areaprimary and productivity). number of different The functional plant community importance types formula and their includes existallintertidal estuarine as separate sand plant and communitiescommunity mudflats) types, orand populations. phytoplankton.namely, salt At marsh,times The theseterm reeds plant plant and communitysedges,community benthic type types ismicroalgae areused found as the (foundas plants in dothe not intertidalwatermonospecific on communitiesthe slack stands. low The twice.tide. extent This Average allowedof the primary phytoplankton for comparison productivity community with values other weretype plant wascalculated community calculated from types as available the without area South includingcovered by andAfrican similar literature genera (Table found 4.1). in overseas The exception publications was the have values been for used theTable forsupratidal the 4.1: present. Primary salt marsh productivity (Colloty values et al. 2000) for the nine estuarine plant community types. SpeciesSupratidal salt Productivityd.w.(g biomass m2.y1) Locality (Estuary) Reference Methods AveragecynosuroidesmarshSarcocornia oleyni 836880792 Louisiana, USA Hopkinson et al. 1978 Change in biomass AverageSpartinamarshIntertidal maritima salt 651651 Swartkops Pierce 1979 Change in biomass SchoenoplectusTyphaReeds lafifoliaand sedge 1 249004 Swartvlei Howard-Williams1980 and Liptrot Production/biomassratios Phragmiteslittora/islittoralisSchoenoplectus austra/is 930960 SwartvleiBot River 1980Howard-WilliamsBally et al. 1985 and Liptrot ratiosProdChange uctio in n/bio biomass mass AveragePhragmitesPhragmifes australisaufra/is 12 621790384140 SiyayaBotSwartvlei River BenfieldBallyAllansonHoward-Williams et al. 19841981 1985 and ChangeUnknown in biomass macrophytesSubmergedChara globular/s 236231 Swartvlei Howard-Williams1980 1978and Liptrot 02method Light/dark bottle pectinatusPofamogePotamogeChara globu/aris fon 2 230506 415 SwartvleiBot River BallyHoward-Williams1980 et al. 1985 and Liptrot 02ratiosProduction/biomassChangemethod Light/dark in biomass bottle pectina fus 39 Allanson 1981 method Table 4.1 continued RuppiaPotamogeton cirrhosa pectin us Species Productivity(g biornass 4 124 83 SwarvleiBot River Locality (Estuary) Howard-WilliamsBally et al. 1985 and Liptrot Reference ChangeProduction/biomass in biomass Methods AvicenniaAverageMangroves marina 16013 056316 MhlathuzeSt Lucia SteinkeSteinke1980 1995 1995 LifterLitterratios production AverageRhizophoraBrugueria gymnorrhiza mucronata 1 498835 917824702 MhlathuzeMgeniSt Lucia SteinkeSteinke 1995 1995 Litter production microalgaeIntertidal benthic 57 Swartkops Pierce 1979 DamstraFielding andconversion 182150 SundaysBot River BallyRodriguez et aL 19941985 Fielding(FieldingDamstra andconversionet al. 1988) AveragePhytoplankton 163 (FieldingDamstra conversionet al. 1988) 182250 57 SundaysSwartkopsBot River BallyHilmerPierce et 1979et al. al. 1985 1990 conversionHenry et al. (1977) EnteromorphaMacroalgaeAverageCaulerpa filiformis sp. 329129163 SundaysSwartvlei TalbotWhitfield et 1988al.1990 Production/biomassChange in biomass SwampAverageCladophora forest sp 196132 Palmiet Branch et al. 1984 Changeratio in biomass AverageBarringtoniaHibiscus tiliaceus racemosa 12 8902201 560 Siyaya Schleyer and Roberts 1987 Litter production 40 -n (0 -ic CD

1 D) Plant community type richness 00G) Functional importance score 0D)00-i Q - Is) O) 4 (Ji O) 4 O (O Berg (Groot) F) K) 01 Q 01 Q 01 00. Q Q Q Q Q Q Q Q Q Q Gamtoos Q Q Q Q Q (DCD Q Q Q Q Q 0 Q Q Q Q Q Q (D = Great Fish 0(/)Q) Berg (Groot)

Grout Brak Gamtoos 0 (D0 Keiskamma Great Fisc- Groot Brak Kobonqaba D)CD u Keiskamma 0. Langebaan D) Kobonqaba Mdumbi - Langebaan m - U) Mhlathuze

- Mdumbi CV- O) I Mpekwenl O) Mhlathuze - - Mtana Mpekweni

Mtana Mtati . Mtati u Mzamba

Mzamba Ngqusi\lnxaxO Ngqusi\lnxaxo

Olifants Olifants I St Lucia St Lucia

Swartkops Swartkops u Umgazana Urngazana Plant community type rarity Plant species richness - - N) N) O) O) o o o o o o 0 01 0 (ti 0 01 0 01 0 b b b b P .- Berg (Groot) O N) . O) O) - N.) . 00G) Bira 00-s Berg (Groot) -,0O-o Gamtoos (D 0 Gqunube (nO. Gamtoos Great Fish Great Kei (D(D Great Fish 00. Groot Brak c u 000 Groot arak Kabeijous . Keiskamma o: Keiskamma Knysna o Kobonqaba Kobonqaba - Krom Oos Langebaan Langebaan Mbashe Mdumbi Mdumbi Mgwatana Mhlathuze

Mhlathuze Mtatazi Mpekweni Mpekweni -U Mtakatye] -u Mtana Mtana Mtata 1 Mtati Mtati U Mtentu Mzamba Mzaniba Nahoon Ngquarrtnxaxo - Ngqusi\Inxaxo Nqabara Olifants Olifants Seekoei 0(D(D-t 1 E St Lucia St Lacia 0 Sundays -s (Do Swartkops Swartkops O - Uilkraals Umgazana Umgazana Xora (D< ( C

(D O Theg(Areah)Functional formula + forh(Areamacro) importance the functional + i(Areaswamp) importance is as follows (Table 4.2): a(Area) + b(Area1) + c(AreaSUb) + d(Arearee) + e(Areaman) + f(Areaben) + Table 4.2: The community types and average productivity values for the different estuarine plant community types used in the functional importance rating. Area Plant community type (cover in ha) = Supratidal salt marsh abbreviationProductivity a Productivit(g m2 y1)y value 836 Area1AreabenAreama,AreareeAreaSUb = == Reeds MangrovesIntertidalSubmerged and benthic sedges macrophytes microalgae Intertidal salt marsh decbf 1 835384316 124651 AreaswamAreamacroAreah = Phytoplankton = MacroalgaeSwamp forest hg i 1 890 196163 eachThe functional of the rating importance components scores separately, were then but applied the following to the followingwill serve ranges as the examplein Table 4.3.of score This generation.was done for Table 4.3: The range of normalised functional importance scores and the respective functional importance scores used in the botanical importance rating system. Percentile Number of Range of normalised Functional 0.20.0 estuaries 100 79 functional importance importance scores 0.1-0.2 <0.1 score 20 0 3.40.80.71.5 34476069 2.8-5.02.1-2.70.2-11.4-2.1 .5 65504030 36.981.0 6.2 2213 1 14.4-70.55.0-14.3 >70.5 100 7585 region,Example: is shownCalculation in Table of the 4.4 functional importance score for the Mngazana Estuary, found in the Transkei 43 Table 4.4: Functional importance of the Mngazana Estuary found in the Transkei region of the Eastern Cape Province. PlantIntertidal community salt marsh type coverArea(ha) 1.3 productivity Area x 813.7 MangrovesReedsSubmergedSupratidal and salt sedges macrophytes marsh 145.0 11.4 0.87.45.6 266075.0 15777.616 052.8186.4 NormalisedFunctionalSwampPhytoplanktonIntertidal forest benthic importance score microalgae score 49.8 7.8 312 604.0 13 884.0 8 120.1 694.4 15.6 finalTheobtained Mngazanafunctional the importance highestEstuary functional had score a normalised ofimportance 85 when score appliedscore of 15.56 of to 2 the 009 when set 023. ofit wasrangesTherefore, normalised shown the inMngazana against Table 4.3.St EstuaryLucia which obtained a 4.2.2.2ofA speciesplant Speciesspecies list was richnessfor compiled each estuary for the was 179 used estuaries as a species included richness in the national value. The importance species rating.richness The score total was number obtained using the ranges in Table 4.5. Table 4.5: The number of species that might be found in an estuary and the respective species richness score. The species richness scores were obtained using a percentile range test. Number of species 1-4 richness score Species 40 17-2012-165-11>20 100 908060 richnessExample: score The Mngazanaof 100 as determined Estuary contains from Table 22 estuarine 4.5. plant species. This estuary received a species The4.2.2.3richness number Plant score. of community The plant typetypes community richness present type was richness applied scoresto the ranges are obtained in Table from 4.6 a to percentile obtain the range community test. 44 Table 4.6: The number of community types that might be found in an estuary and the community richness score. respective communityNumber types of plant 1-3 Plant communityrichness score 20 7-9 654 100806040 community4.2.2.4Example: Plant type The community richnessMngazana score type Estuary of rarity 100 contains as determined eight of fromthe nine Table plant 4.6. community types and received a plant A weightthatit receivescommunity has been a weight type assigned only of 1/35. occurs to the The once,six weights least it receives common of each a community communityscore of one. types type foundfound in eachSouth estuary are If a community type is found in 35 estuaries Africa. For example, if then added, to obtainobtain a finala plant score. community An estuary type will rarity have score, a high the score sum ofif itweights contains wasTable many then 4.7: community applied Rarity toweights thetypes ranges and the in respective community rarity scores. that are rare. To Table 4.7. Sum of weights 0.020-0.0290.000-0.019 Plant community type rarity score 4020 0.051-0.0670.041-0.0500.030-0.0400.068-0.130 100958060 Example:calculation: The Mngazana Estuary contains five plant community types used in the plant community type SupratidalIntertidal salt salt marsh marsh - 0.024- 0.016 (found (found in in 42 61 estuaries) estuaries) rarity SwampMangrovesSubmerged forest -macrophytes 0.027 - 0.04 (found (found - in 0.026 in 37 25 estuaries) estuaries)(found in 39 estuaries) Therefore,number ofthe plant Mngazana community Estuary types receives that are a rare. community rarity score of 100 (Table 4.7) as it contains a Total 0.1331 high 45 4.3 RESULTS determineSixty five percent their botanical of the estuaries importance. found The in Southraw data Africa of the (179 estuaries estuaries) are had given information in the Appendix. that could Table be used 4.8 to 400.thesesummarises Twelve estuaries of thethese ranged national estuaries from botanical 245 occur - 400, importancein whereasthe former forof Transkeithe all South36 estuaries region African and with estuaries seven the highest in the the scores formerscores. ranged Ciskei The scores fromregion 20 of of to includedtheThe Eastern combination in the Cape estuaries of Province. the four with componentsThis the highestmeans thatinscores. the 16% botanical of Transkei importance estuaries rating and system 44% of allowed Ciskei estuariesestuaries toare be componentsrated important towere influencefor not different weighted the reasons final and score alland scores for not an only estuary.ranged according between to size.O and This 100. was This because allowed the each individual of the TheEstuariesimportance St Lucia, were Mngazana,scores, ranked community highKnysna because richnessand Swartkops of their and highcommunity Estuaries functional raritywere importance (Tableimportant 4.8). and because The species Berg, they richness Mbashe had high scores, and functional Nxaxo plant communityOrangeFive estuaries and type Langebaan richnessthat were Estuaries. scores expected or plantThese to have community estuaries higher importance weretype rarityranked (Tablescores lower 4.8). included than expected the Berg, through Mhlathuze, either Olifants,having Africa.Estuarylow species However, was richness,expected although communityto these have mangrovesa high richness national coveror communityimportance 652 ha, species rarityas it contains(Table richness 4.8). the overall Inlargest particular, is mangrove low (11the species).Mhlathuze stand in South scores.functionalThe combination For importance example, of the thescores, components moderately which havein sized the rich botanical (between or rare importance plant141 and community 286 rating ha), allowedtypes, temporarily and the led small open to. highestuaries Mtati, importance Mgwalana with low and remainingMlalazi,Mpekweni Nqabara,estuaries Estuaries nNahoon, Table found 4.8 inMdumbi the all hadformer and lower CiskeiKobonqaba. functional region However,wereimportance rated these of between estuaries 50 were and 75,included such asin thethe 36 11th and respectively (Table 4.8). The estuaries.estuariesThree estuaries with the that highest were scoresnot expected because to bethey ranked had mangroves in amongst that these are 36 found estuaries in only were 37 South the Kabeljous, African macroalgaemoderatelySeekoei and smallor Uilkraals. submerged and temporarily These macrophytes three open/closed. estuaries that depend are However, found on inmouth these the South condition.three Cape estuaries Past region areahave of assessmentsSouth large areasAfrica, of arefor these estuaries were undertaken during their closed states when large areas of the submerged macrophytes had 46 importance(Appendix).developed. InofThis somethese coupled cases,estuaries. with these the Consequently, planthigh productivitycommunity these typesvalue estuaries dominateof this received plant up community to high 65% botanical of the type, entire importanceelevates estuary the scores. area functional Tablearecomponents indicated4.8: The of36in the bold.estuaries botanical with importance the highest formula botanical are importance shown and scoresthe final in botanicalSouth importance scores Africa. The Botanical StEstuary MngazanaLucia importanceFunctional loo 85 richnessSpecies Plant community100100, Plant community type richness 10080 type rarity 10095 importance 360385400 SwartkopsMbasheBergKnysna (Groot) 658575 1008090 10080 1008095 345350 OlifantsMlalaziKeiskammaNxaxo 75655085 100908060 10080 1009595 330335340 XoraLangebaanMhlathuzeKrom Oos 658575 100908060 808060 1008095 315320325 GreatSundaysGamtoosMgwalanaMtati Fish 657550 1009080 6080 8095 305315 NqabaraGreatNahoonMpekweni Kei 50406530 906080 6080 10080 280285290280 GrootMdumbiMtataBira Brak 305075 6080 608060 10080 270275 KabeljousMzambaMtanaKobonqaba 306550 806080 804060 9580 265270 SeekoeiMtakatyeUilkraalsMtentuGqunube 65306550 609080 406020 9580 245250255265 47 4.3.1Warm Botanicaltemperate importanceestuaries in the different biogeographic regions Knysna,SouthThirty estuariesAfrican Swartkops, coastline had theNxaxo (Tabletwenty and 4.9). highestKeiskamma Nine botanical of theseEstuaries importahce are foundhad the inscores highestCiskei in andthescores warmfour as in temperate aTranskei result of (Tableregiontheir high 4.9).of the The Swartkopsmangrovesfunctional importance Estuaries that resulted contain and in species-richness the extensive high community inter- scores and richness supratidal (Table and 4.9). salt rarity marshes,The scores. Nxaxo reed, TheEstuary sedgesKeiskamma, contains and submerged Knysnaa fringe andof Keurbooms,Mhlathuze,macrophytes. Berg Tyolomnqa When and theOlifants andlarge Silvermine Estuaries) subtropical Estuariesthen and the cool Koega, were temperate ranked Bot/Kleinemond, estuaries more important are Gqutywa, not in considered this Hartenbos, comparison (Mngazana, Qinira, (Table 4.9). thattheThis scores increasedincreased ranged thethe speciesfromrange 245 of richness botanical- 400. The and importance estuaries community thatscores richness had from the scores 230twenty - 374,(Table highest while 4.8). scores for the all national contain comparison, salt marsh Table 4.9: Thirty warm temperate estuariesEstuary with the highest bofanical importance scores. importanceFunctional richnessSpecies Plant communitytype Plant richness community Botanical type rarity importance KromKeiskammaNxaxoSwartkopsKnysna Oos 75655085 1008090 10080 10095 330340350340360 GreatSundaysMgwalanaGamtoos Fish 756550 1009080 6080 8095 305315 NqabaraGreatNahoonMtati Kei 40653050 608090 806080 10080 280285290300305 KobonqabaGrootBiraMpekweni Brak 3050 608090 8060 100 80 270280 GqunubeUilkraalsKabeljousMtana 6530 906080 8040 8095 265265270 KartenbosGqutywaKoegaBot/Kleinmond 303085 100608090 40806020 8020 250255 QiniraSilvermineKeurboomsSeekoei 406530 6090 4060 804080 220235245230 Tyolomnqa 40 80 48 60 40 220 SubtropicalTwenty-eightPermanently estuaries openestuaries estuaries had the that top contained twenty highest mangroves scores and in swampthe subtropical forest (Table biogeographic 4.10) had the highest scores. region. allreceivedSt Luciathe plant Estuarythe community highest is the scores largest types. in allsystemSixteen components in of South the subtropical of Africa the botanical and estuaries covers importance approximately were found rating as in Transkei (Table38 290 4.10). ha. ThisNo estuary it has extensive areas of functionalcharacterisedCiskei estuaries importance, by occurextensive inspecies the mangrove subtropical richness (145 andregion. ha) community and The salt estuary marsh richness with areas andthe (25 secondrarity. ha). The highestThis score, resulted the inMngazana a high is remaining estuaries showed andlowa wide functionalcontain range only of importance scores reeds, from sedges and 160 community and to 400 swamp as richnessshown forest inspecies, scores. Table withMost some of these estuaries are 4.10. Low scores could generally be attributed to containing submerged macrophytes. small or channel-like surveyed.Swamp forest This only elevated occurs the in scores25 of the of 179the smallestuaries, estuaries whereas that reedscontained and sedgesswamp occur (Table 4.10). forest and submerged in 151 of the estuaries macrophytes such as the Siyaya (7.69 ha) and Mdlotane (25.42 ha)Table Estuaries 4.10: Twenty eight estuaries with the highest scores in the subtropical Estuary Functional Species Community Habitat region.Botanical St MbasheMngazanaLucia importance 1006585 richness 100 6080 richness 100 rarity 100100 importance 400335345385 XoraMtataMhlathuzeMlalazi 756585 6080 8060 1008095 270275320325 MtakatyeMtentuMzambaMdumbi 30503050 6080 60 959580 245250265 MhlangaSiyayaMzintlavaMntafufu 7530 204060 402060 95 245230 MdlotaneMdlotiNhlabaneMzimvubu 403065 6060 4040 6095 190200225 MnyameniMkomaziMgwegweMbotyi 30 8060 40 406060 190 TongatiMsikabaZinkwaziMtamvunaKwa-Suka 40302065 206040 4020 6040 160170180185 49 4.4 DISCUSSION photographsTocomm.). summarise However, and the satellite importancealthough imagery both of thethese has South been studies African found have tocoastal bebeen óost vegetation,able effective to determine (Raalmapping and the the Burnsextent coastal 1996;and region status Knight using of the aerial pers. small-scaledifferentThe botanical vegetation vegetation importance units units (biomes of thatan estuary occur and vegetationin has estuaries. previously types), been neither assessed could determineusing the functionalthe importance importance and status rating of species2000;and Riddinmore richness recently, 1999). and Criticisms the habitatuse of of areaintegrity the functionalmeasurements, of an estuary importance will (Coetzee always rating etbias system al. larger 1997; have estuariesColloty been et that as al. more 1999,it does important. Colloty not include et al. identified.moreLarge species estuaries These or suchcommunity include as theestuaries typesOlifants, such such Mhlathuze as as those the Mngazana, andestuaries St Lucia in Nxaxo theare Ciskei important, and Keiskamma and Transkeibut other that alsoestuaries have need diverse thatto be have plant communityTranskeiIn this section and types compareda revised and support botanicalthese a to high otherimportance number South ofratingAfrican species. system estuaries. was Theused largest to rate estuaries the estuaries such found as St inLucia, Ciskei Berg, and Africa.extensiveKnysna For areasand example, Langebaan of estuarine St Lucia Estuaries plants has the that were third contribute ratedlargest important largemangrove proportions on areaa national of to 279 the basis. ha, total while Theseestuarine the estuaries Berg, plant Knysna cover contain inand South supratidaldifferentLangebaan physical zones Estuaries inenvironments these have permanently large have salt led open marshes. to the estuaries. creation The large Differentof different area plant (morphology) habitats, community i.e. coupledintertidal, types occupyto subtidal the diversity these and habitats of AfricanandHowever, thus systems. these a number Thispermanently hasof small occurred openestuarìes throughestuaries were the hadalso inclusion arated high important botanicalof additional withinimportance. components the twenty tomost the importantbotanical South proportionAllimportance the components of species, formula. that plant An have estuary community been is included important types in and theif it community hasbotanical a high importance typefunctional rarity. ratingimportance system and have contains been showna significant to a lowerhavedue to annumber a independentwide ofrange species of effect scores and on plant found the communityrating between of an estuaries. typesestuary than as For thethere example smaller was no Mngazanaa largecorrelation estuary Estuary. between such Estuaries as them. the Olifants This that had was atowere particular either previously a high community numberregarded typeof as species, tounimportant total plantcover communitybecause in South ofAfrica. typestheir small or these size estuaries now have contribute higher importance a significant scores portion due of 50 A numberchangesHowever, of in small water if the estuaries levelKabeljous, and in salinity theSeekoei Cape occur. and region TheseUilkraals also changes received Estuaries in high physical had been assessed botanical importance rating scores.conditions resulted in the replacement when their mouths were open, andof importancethe overall submerged botanical of an macrophytes estuary, importance especially by would the lessthose have productive thatbeen fluctuate lower. macroalgae Carebetween has species differentto be states. taken in ratingand the their botanical functional importance Measuring the area typeand-whitecovered could by photographsbe submerged used as an plantsare area used. from cover The aerial value. maximum photographs This availablecould beis difficult ahabitat solution at suitable times. if Thisfor is the particular estuary is well that particular plant community especially true when black- understoodTheplans botanical or identification and importance confidence of rating conservation based formula on expert canneeds. beopinion usedComponents is in high. decision of the support, botanical estuary importance prioritisation, management rating have been used al.partin a 1999). systemof the Estuaries RDM to assess approach were the prioritised overallin determining health based and the on conservation ecological size, type, reserve habitatimportance required rarity, of botanical South by the Water Act of 1998 (TurpieAfrican et estuaries. Thisimportance, forms invertebrate, fish follows:forand water bird Knysna, importance.from a particularOrange, Other Mhlathuze, system. aspects The that Olifants, 20 were estuaries includedSt Lucia, with wereBerg, the degree highestKosi, Mhlathuze, ofscores protection, in thisTugela, prioritisation Klein, Bot/Kleinmond,were as threats and futher demand estuariesthisMngazana, study showthe Great botanical a wideFish, range Swartkops,importance of very Krom,of important estuaries Gamtoos, to are the rated Keiskammaleast inbotanically a similar and Mlalaziorder.important The Ciskei Estuaries (Turpie et al. 1999).estuaries In in South Africa. and Transkei ThissufficientHowever, is discussed informationthis can further easily becomes in bethe done following available. for the section. otherThe Transkei biogeographicIn this study region only regions,probably these provincestwo has the highest or types regions have been compared. number ofof important estuaries once temperateestuaries withthan and theanysubtropical. highest other region. scores. Overall, This is 16%because of the the Transkei Transkei estuaries region is were a transition included zone in the group of 20 between the warm TheEastCiskei information London and Transkei region used in(Walkerestuaries. the national pers. A high commrating level was1999) of obtainedconfidence and KwaZulu-Natal from can various be assigned (Riddinsources. to 1999 Thisinformation and study surveyedPillay all the 1998 cited for estuaries in the macroalgaeTheRiddin remaining 1999) and estuaries. estuaries swamp However, forestin the speciesKwaZulu-Natal species are informationnot wellregion known also for theforneed Westernthe investigation. small CapeKwaZulu-Natal estuaries In needsestuaries. to particular, the distribution of be updated. 51 5 THE BOTANICAL5.1. INTRODUCTION IMPORTANCECISKEI OFAND ESTUARIES TRANSKEI INREGION THE FORMER regionsIn this (Eastern study, botanical Cape Province, surveys Southwere conducted Africa) and in the 92 revised estuaries botanical found in importance the former rating Ciskei system and Transkei was timedispensationapplied and their to these condition of the estuaries. country was believed Thesewas introduced two to beregions important in 1994.were for independentThe two areas reasons, involved states viz., beforecanwere unmanaged largely the present unmanaged estuaries political during survive that Africa.forsecondly, a period ofwhat approximately was the state 30 ofyears these in estuariesa heavily bearingpopulated in mindregion the without rapid beingexpansion seriously of water degraded, use in theand South The5.2 methods MATERIALS used inAND this METHODSsection are explained in Section 4. 5.3All sixteen RESULTS Ciskei estuaries are shown in Table 5.1. The Keiskamma Estuary received the highest botanical supratidalcommunityimportance salt rarityscore marsh, scoresas it reeds,had in thethis sedges, highestregion. submerged functionalThe Keiskamma importance,macrophytes is a large species and permanently extensive richness, intertidal opencommunity estuary sand richness and with mud intertidal, and flats. contained.estuariesThe remaining had The the estuaries Great same Fish plant were and community ranked Tyolomnqa in ordertypes estuaries ofwith decreasing only were variation the functional exception. in the importance.number Both theseof plant This estuaries specieswas because hadthey low these developmentbotanicalestuaries (Tableimportance of extensive5.1). scores areas due ofto estuarinetheir narrow plants. channel-like Only salt nature marshes with and small reed floodplains. beds This restricted the were found in these componenttheThe 20 most most important of important the botanical estuaries Transkei importance in Transkeiestuaries formula were contained the contributed permanently mangroves to the open (Table high ones scores 5.1). that The of had these functional estuaries. importance, The Great mangroves. Eleven of thehadKei Mbotyi, large and saltGqwara Bulolo marsh andEstuaries areas Hluleka and, were contained thus, also high included extensive habitat in raritythe areas twenty scores of reed estuaries (Table and sedges.5.1). with Thethe Thehighest remaining Msikaba, scores estuaries Mgwegwe because such theyand as 52 functionalMzamba Estuaries importance are and moderately community small rarity and scores contain of theseswamp estuaries. forest. These swamp forests added to the Table 5.1: Botanical importance of all 16 Ciskei estuaries and the 30 Transkei estuaries scores. Ciskei Transkei with the highest MpekweniMtatiKeiskamma Estuary importanceBotanical 310350365 MbasheNxaxoMngazana Estuary importanceBotanical 370385 MtanaBiraGreatMgwalana Fish 270295310330335 GreatXoraMtataNqabara Kei 310330350 OldKiwaneTyolomnqaGqutywa woman's 225255185195 MtentuMtakatyeMdumbiKobonqabaMzamba 285295305 Shwele-ShweleBlueNgqinisaNgculuraFreshwater Krans Poort 145160 85 MbotyiMzimvubuMzintlavaMntafufu 225250265 QoraMgwegweMsikabaKwa-SukaMnyameni 200205210215225 MbhanyanaBulunguluMnenuGqwara 185190 ButshaNgqwaraKu-MpenzuGxaraQolora 165170 The5.4 botanical DiSCUSSION importance AND CONCLUSIONrating for the Ciskei and Transkei estuaries indicated that large permanently open sizeestuariesbasis with of the similarwere combination important species and ofas all they plant the had componentscommunity high functional types. in the Onimportancerating a national system. scores. basis On a Theestuaries regional smaller scale,were estuaries clearlyas seen wereranked on in the of similar the decisionsscoresCiskei, variationbecame is determined. thein species dominant For richness example, variable. and theThis plant estuaries must community be found taken type ininto the richness account Transkei is less should and be the managed functional in importance terms when the scale of management of improving agricultural practices as shown by the number affected by this activity (Section 7). 53 6: THE INFLUENCE OF THE PHYSICALDISTRIBUTION ENVIRONMENT OF ESTUARINE ON THE PLANTS IN THE FORMER CISKEI 6.1 INTRODUCTION AND TRANSKEI REGION. TranskeiFor the regions first time of a the survey South of Africanall the macrophyticcoast. In the plant previous community section types it was was shown undertaken that the alongestuaries the Ciskeiof the and temporarilystudyrichness region andclosed had plant a estuaries.high community botanical However, type importance. rarity. these Functional estuariesThis was importance hadunexpected a high specieswas as mostlow richness,due of these to the plant systems small community size are of small the type estuariesvariationlt has been of(Section morphology well documented5). (Cooper that et al.habitats 1999). that They form may at theform interface lagoons, between estuaries, land coastal and the pans sea or show river a mouths wide havedetermines(Harrison been et colonised theal. 1type 999a; of by environment1 specialised 999b). Furthermore thathalophytic is produced. the plants. hydrology This These has and can resulted geomorphology be divided in a number into of a eachnumber of unique system of separatehabitats largely that mangroves.periodicgroups based tidal inundation. on their interaction These include with the salt estuarine marshes, environment, submerged specifically macrophytes, the reedsdegree and of tolerancesedges and to suchnecessitatedFurther a system variations the a summarydevelopment in the morphology of the of physicala geomorphologic of estuaries environment are classification so would varied aid that the system little determination apparent for estuaries. order of inter-estuary The exists. hope This is patterns thathas with coastlineidentifiedand relationships (Harrison within the et (Cooper al.two i 997a;study et al. regions1 997b;1999). andHarrison Such each a system etgroup al. 1 showed999a;has been i 999b).a transitionapplied Several to along the groups fish the fauna coastline of estuaries of the depending South were African on thewelllt estuary isas suggested the studytype andregionsthat consequentthe beingvariation a transitionfish in estuarineassemblages. zone morphology between (Harrison the coupled warmet al. 1999a;temperatewith changes 1999b). and in subtropical hydrology biogeographicand climate as types,theregions increased plant have presence ledbotanical to the and increaseimportance absence in plantofwas this relatedrichness region. to and Inmeasured order community to describephysical type variables.therichness. distribution ThisCoetzee hasof plant (1995)consequently community showed led that to basedcompositionplant community on species was coverbetter composition could correlated. not in accuratelyrelation Using toordination, describethe physical the variationdifferentenvironment. groupsin estuary These of estuariestypes, groups whereas werecan then then species be compared identified to those in the geomorphologic classification. 54 6.2 MATERIALS AND METHODS A standard6.2.1 Botanica! procedure surveys was adopted for investigating all the Ciskei and Transkei estuaries. Water column temperature,measured.samples were lightInformation collected attenuation, on from the nitrate five macrophytes stations, concentration, approximately was collected phytoplankton equidistant, in order and to benthic determinealong each microalgal plant estuary. community biomass Salinity, weretype plantrichness6.2.2 communityPhysical as well variables astypes species using composition. maps and aerial This photographs information wasas described used to determine in Section the 4. area covered by the attenuation340Salinity -A). (g.é1) Surface was and calculated and temperature bottom as readings follows: (°C) were were measured taken. Secchi using diska conductivity depth was /temperature measured at metereach station and (WTW model LT light Where K is the light attenuation coefficient and depth is measured in metres. K (m') = 1.7/secchi depth ofWater collection.nitrate samples concentration. The (250 copper me Theseeach) cadmium weresamples method collected were for atkept the the determinationin surface a cool boxand withbottomof nitrate ice ofpacks wasthe water usedand analysed column(Bate and for within the analysis24 Heelas 1975). hours spectrophotometerTotal6.2.3 nitrateOrdination concentration at 450 nm.was determined as a function of reduced nitrite that was read on a Cecil CE 303 analysedvariablesOrdination andusing techniques the canonical geomorphology were correspondence chosen of to the describe estuaries. analysis the Presence/absence relationships(CCA; Ter Braak between 1986). of the species CCAwasestuarine distribution, utilised plant species tophysical determine were estuary.werespecies-environment average nitrate concentration,relationships with light the attenuation, PCORDWIN salinity, (1996) temperature, package. Environmental water column variables included depth and size of All6.2.4estuaries 16 Ciskei Estuarine have estuaries been classification wereclassified surveyed by- a Harrison geomorphologic by Harrison et al. et(1999a; al. approach (1997a; 1999b) 1997b) (Table (Table 6.2). 6.1)They and were 43 placed of the 76into Transkei one of the seven different geomorphologic classes. A few examples of these are shown in plate 6.1 to 6.5. 55 Table 6.1: The classification of estuaries compiled by Harrison et al. (1999a; 1999b) for the 16 Ciskei estuaries. (The estuarine classes (Whitfield 1992) are also shown.) lA Estuaryclass TemporarilyWhitfield class FrequentlyHarrison closed class Moderately(ha)Size Long wide Barrier type near(g.é1)Salinity marine, Mpekweni, Estuaries i B Temporarilyopen/closed Frequently closed Moderately9small - 25 Longbarriers wide nearwhendominatedoverwash marine, closed OldMtana,Gqutywa,Mgwalana,Mtati, Woman's, Kiwane Bira, 2 Permanentlyopen/closed Near permanently Large5-12small -barriers whendominatedoverwash closed 3 estuarineNotopen considered bedsSmallopen or dry river Small40 - 150 <5 Long O0Range - 355 of Thatshana,TyolomnqaFreshKeiskamma,Great Fish,Water 4 Temporarily Freshwaterchannelsfreshwater Small 5 Perched 5 - ii ShweleNgculuraKrans,Poort, BlueShwele- Table 6.2: The classification of estuaries derived by Harrison et al.closed (1999a) for 43 of the Transkei estuaries. The Whitfield estuarine classification is also shown. channelsdominated tideabove level neap lA Estuaryclass open/closedTemporarilyWhitfield class TemporarilyHarrison classopen small(ha)SizeModerately <5 brackishfreshVary(g.e1)Salinity fromor barrierPerched Barrier type Mpenzu,Zalu,Ngogwane,Estuaries Ngadla, Kwa-Suka, Ncizele, Ku- 0.03 - li Thsani,Mtumbane,Gxwaleni,Sinangwana,Sundwana, Bulolo, Ntlupeni,Nenga, 21 B Temporarilyopen/closed TemporarilyopenNear permanently open Moderatelysmall 5 - 15 16O - 3518 -Perched Jujura,Gxara,Butsha Mapuzi Qolora Cebe, open/closed small 5 15 barrier MtentwanaMgwetyana,Mpande,Ntlonyane,Ngqwara, Mgwegwe, Ku-Bhula, Nkanya, 3A openPermanently openNear permanently >15 OgradientAxial - 36 - Qora,4),Mntafufu,Mdumbi,Kobonqaba Ngqusi/lnxaxo, Shixini, Mngazi, Mzamba Xora,(Plate 3C3B openPermanently openNear permanently 25250 ogradientAxial - 36 - Mngazana 4 openPermanently or River RiveropenNear permanentlydominated 50 range,Small0-36gradientAxial tidal - MzimvubuMbashe,Msikaba andMtata, and Mtentu Great mouth 56 <2 km Kei. Plate 6.1: The Sinangwana Estuary found in the former Transkei region s classified as a open/closed estuary (Class lA). lt has a surface area of ca. 4.5 ha. temporarily

Plate 6.2: The Jujura Estuary in the former Transkei is classified as a Class 1 B estuary. prism.example The of tidala near amplitude permanently was 1.2open m systemat the mouth due to during its large a spring catchment tide onrather 19/04/98. than the tidal lt is an 57 Plate 6.3: The Qolora Estuary is a large temporarily open estuary, typical of Class 2 estuaries. Thistypemouth of estuary closes hasquickly a perched due to thebarrier high and wave only energy breaches conditions after extended along the rainfall coast. events. The 58 Kobonqaba Estuary (Class 3A)

Mngazana Estuary (Class 3B) Plate 6.4: An example of a Class 3 estuary which is a large system with a tidal prism that maintains a Mngazanathenear local permanently geology. Estuary openThe (Class Kobonqaba inlet. 3B) Differences is characterised Estuary in (Classthe by size tidal 3A) and mudhas location sand flats. flats of at the mouth; the sand/mudflats are due to 59 Plate 6.5: Class 4 estuaries, such as the Mbashe, include all river-dominated estuaries. 60 6.3A total RESULTS of 54 estuarine plant species occurred in the 92 estuaries observed in the study region. Plant species couldphysical(20 bespecies), divided environment mangroves into the data following (4 are species), presented five plant macroalgae incommunity Section (3 11 species) types: - Appendix. reeds and swamp forest and sedges (23 species), salt marshes (4 species). Species and theanalysisFifty driving five whichof environmentalthe indicatedestuaries thathad factors salinity,sufficient in the average physicalspatial waterseparation and speciescolumn of nitrateestuariesinformation concentrations to be and the plants within them (r> 0.05). used in a CCA multivariate and size of estuary were (rordinationsThe = 0.530)highest and (Figs. correlation water 6.1 columnand was 6.2). shown nitrate The between speciesconcentrations andaxis estuariesone (r and= 0.43 two had 1), for the while species highest light correlation (r = 0.534)attenuation and estuary (r = 0.384) (r = and0.653) depth between salinity characteristicssalinity,(r = 0.241) nitrate had that concentrationsless were of ana function effect and on of light distribution.geomorphology attenuation). Estuaries (surface These could groups area) thus andalso be physico-chemical groupedshowed similaritiesaccording to in similar species physical factors (average speciescomposition.Permanently to define Allopen the 8 estuariesdifferent estuaries groups.with had extensive reeds These and groupssalt sedges, marshes were but as occurringthere follows: was south sufficient of the separation Great Kei River Estuaiy. within the other plant 25EstuariesThe ha. Great However, all Kei had River theintertidal (222Keiskamma ha), and Tyolomnqa supratidal and Great salt (107 Fish marshes. ha), River Keiskamma EstuariesAll four estuaries (344 had larger had areas large of ha) and Great Fish River (365 ha) salt marshes greaterintertidal than salt marsh. ordinationThisnatalensis was reflected (Fig. (Bunge 6.1, in Group exthe Ung.-Sternb.) intertidal A). These species speciesA.J. Scott,composition included Chenolea Triglochinassociated diffusa striata, Thunb.,with these Cotula two filifolia Thunb. Sarcocornia perennis, Sarcocornia estuaries seen in the and Límonium L.,shownscabrum Disphyma in Thunb.the ordinationcrassifolium The Tyolomnqa (Fig. (L.) 6.1, L. Bol., andGroup SporobolusGreat A and Kei Fig. River virginicus, 6.2, Estuaries Group Stenotaphrum A). had These more supratidal species included Triglochinsecundatum, bulbosa Salicornia species present as thehavemeyeriana estuaries incised Moss riverreceive and banks theSarcocornia causedlargest proportionby pillansii erosion. (Moss) of This their erosionA.J. mean Scott. annualtakes Both place runoff the duringGreat within Keihigh a and three-to-four monthflow period periods that exist when Tyolomnqa Estuaries tidaleachspring exchange year. high This tides takes is usually that place, result in but the in is theform limited supratidal of floodsdue tO conditions. (Midgley the raised et banksal. 1994). and Duringthe marshes the remainder are only inundated by of the year normal 61 PermanentlyTheseNxaxo estuaries(159 ha), open areNqabara estuaries moderately (109 with ha), sized mangroves Mbashe permanently (132 and ha),salt marshXora (151 south ha), of Mdumbithe Mngazana (76 ha) Estuary and Mtata (169 ha) open (Fig. 6.2, Group B), namely the Kobonqaba (62 ha), Figs.(betweenEstuaries. 6.1 and1.84 These 6.2. and estuariesSpecies 1.94 m) foundresultinghad high in these inaverage the estuaries close salinity correlation included (between with the 18 themangrove and depth, 23 g.(1) areaAvicennia and and high salinity marina, average vectors Bruguiera depth shown in bulbosa,gymnorrhízaThe presénce Disphyma and of the Rhizophora crassifolium, red mangrove, mucronata. Sporobolus Rhizophora Salt virgin/Gus marsh mucronata, species and Sarcocorniain foundthe Mtata in these pillansii.and Nxaxoestuaries Estuaries included was Triglochin possibly mucronatameandue to annual the highertree runoff of freshwaterless of 392than x 1,5 106.m3inputs. m in Theheight(Midgley Mtata and et iswill al. a Classneed1994). further4 The river-dominated Nxaxo monitoring Estuary toestuary establishonly has indicated aif thissmall estuaryby juvenile its higher is R. furthersuitableThe Mngazananorth. for its survival, Estuary i.e. can this species survive in an estuary with a higher average salinity than estuaries exceptionltThe shares Mngazana affinities of macroalgae. Estuary with the is Inaall permanentlyterms the estuary of plant groupsopen species one and ofcomposition, has 224 all ha the and plant it differs acts community as from the all dividing estuariestypes pointpresent in betweenthe with study the the region. classThesouthern Mngazana (Class and 3B Estuary northern- permanently has estuaries. a unique open estuary). geology and tidal flat formation that resulted in its own geomorphologic lt also receives regular tidal exchange so that it exhibits a natalensis,Mngazanarange of salinityChenolea Estuary from includediffusa, O g.e' theCotufa at thesalt fil/folia,headmarsh of plantsSal/corn/a the estuary Triglochin meyeriana to 37 striata, g.e1 and at Sarcocornia theLimonium mouth. scabrum.perennis,Species foundTheseSarcocornia in species the are vectorbetterPermanently adaptedin the ordinationopen to high estuaries salinity (Fig. 6.2).north conditions of the Mngazanaand this caused Estuary. the close correlation of these species to the salinity andTheMzintlava, 27following g.e Mtentu moderately and Mzamba sized estuaries (Group (23C, Fig.- 70 6.2). ha) wereThese grouped estuaries together had an in average the ordination; salinity Mntafufu,of between 26 and average depths exceeding 1.6 m. Species found in these estuaries included the two al.inmangrove (1999a; the Mntafufu 1999b)to species Estuary. beAvicennia steep This channel-like marinagroup of and estuaries estuariesBruguiera are with gymnorrhiza, large a small deep floodplainestuaries while Rhizophora andor intertidal were mucronataclassified area. Fig. by was 6.1 Harrison onlyshows found et 62 swampthatLarge these forest temporarily estuaries (Hibiscus openare tiliaceus)al! estuaries closely and associated with reed salt species marsh with indepth.and the macroalgae These estuaries are small areas available. mostly colonised by mangrove closedspeciesThe large estuaries present estuaries (Fig.found (15 6.1, in - 186the Group Ciskeiha) B found and and Fig. insouthern this 6.2 group Group region had D). of salt This the marsh, Transkeiincludes coasta high as macroalgal and submerged macrophyte number of temporarilyfar open- north as the Ncizele overwashmacroalgaeEstuary. present These (Enteromorpha estuariesin these estuaries. hadsp. orsupratidal Cladophora salt sp.).marsh This (Sarcocornia was as a result pillansil, of the high Samolus porosus (L.) Thunb. and salinity conditions due to areSmallThese shown temporarily estuaries as group are closed thoseE and estuaries foundC (Figs. between with 6.1 reedsand the 6.2) andGxara and sedges andare the only Gxwaleni made up of the estuaries classified by Harrison et al. found south of Port St Johns. These ingreatest(1999a; size. These 1999b)proportion estuaries as classof the are lA,types characterisedlB orof 2system temporarily found by salinity open/closedin the of Transkei between estuaries. (ca. 11 56%) These and range estuaries and 17 g t' and varying depths not between 1 .29 and 41 ha makeup the communityexceedingSmall temporarily 1type .4 m. that Species closedprefer thesefoundestuaries brackishin these with reeds,estuariesconditions. sedges (Fig. and6.2, swampGroup F) forest are of the reed and sedge plant (Fig.The swamp6.2, Group forest F; speciesFig. 6.4). Hibiscus Estuaries tiiaceus that are is foundincluded from in thethis Gxwaleni group are between Estuary north towards thePort remaining Edward group B estuaries 1 .92 and 50 ha in size. (MtumbaneTwoOutliers estuaries and not Ntlupeni) found in did this not group, have but the which lagoon the hibiscus ordination (H. tiliaceus)placed with present. ThemangrovesMzimvubu Mzimvubu Estuary in was this classified system. contained These by reed Harrison have and sedge subsequentlyet al. (1999a;species disappeared1999b)as well asas aHibiscus river-dominated tiliaceus. (Section 8). If the mangroves were still Steinke (1982)estuary reported (Class 4). The mangrovespresentThe Msikaba the andestuary Estuary swamp may was forest. have classified been classified as Class in3C, the permanently group of northern open estuaries, permanently with open small mouth barriers and estuaries that had systems,reedssmall intertidaland the sedges. Msikaba areas. With Thiscould similar lack have physicalof possiblyhabitat conditions has been resulted colonised to the in colonisationnorthern by mangroves. permanently by a Thislimited openwas number shown by the closemangrove/swamp forest of species such as ordination of this system to the physical factors associated with tidal exchange and other mangrove 63 systems observed(Fig. 6.1). by ThereWooldridge are no (pers. published comm accounts 1999) during of mangroves his surveys present of this in system this estuary, in the earlyhowever, 1970's. they were shownaureum.The Mkozi as This an Estuary outlier was found was as it the wason onlythe a temporarily upperestuary banks with closed ofthe this mangrove estuary temporarily with associate, the closed submerged theestuary. mangrove macrophyte, The Jujurafern Acrostichum EstuaryZostera wascapensis also Setchell.andFigs. the 6.3associated This and species 6.4 plantsummarise is usuallycommunity the found 7 types.groups in the of intertidal estuaries zone found of permanentlyin the study regionsopen estuaries. together with the estuaries

64 100 - Reeds and sedges s B Attenuation s 4 Supratidal salt marsh, inacroalgae and submerged macrophytes s s Axis i Strelitzia nicolai . s s 20 epth Area .Sophora mucronata Bruguiera gymnorrhiza 605 Intertidal salt marsh . - 80 100 Swamp forest s Hibiscus tiliaceus Ficus sur s Halophila ovalisS Avicennia marina Zostera capensis Mangroves and associates Acrostichum aureum SarcocorniaSarcocornia natalensisdecumbens perennis Group A SalicorniaDisphymaCrassula meyerianacrassfolium expansa Group B ScirpusPhragmitesPycreusGroup maritimapolystrachusC australis ChenoleaSpartinaCotulaTriglochin maritima coronopfoliadffusa bulbosasfriata SamoSarcocorniaRuppiaEnteromorpha lus porosus cirrhosa pillansia bulbosaintestinalis JuncusScirpus littoraliskraussiiacutusnodusustriqueter LimonChondropetalumCotulafilfolia ium scabrum tectomm SuaedaStenotaphrumPotamogetonCynodonCladophora caespitosa dactylon pectinatus secundatum sp. ScirpusJuncellusEragrostisTyphaCyperus littoralis capensis laeviagatus littoralistextilis AxesAxisSpeciesEigenvalues: i and -2 Environment correlations Salinity 0.90.5 1 Depth 0.40.7 2 Light attenuation 0.60.4 3 Figure 6.1: CCA ordination of plant species presence/absence in Ciskel and Transkei estuaries that were averagedistributionsurveyed.correlations salinity Spatial of plantsfor and theseparation secchispecies first three depth. areof axes.the shown. The estuaries table Environmental insertin relation shows tovariables theenvironmental eigenvalues include variableswater column and thedepth, 65 and species-environment 0000 loo ¿ TemporarilyPermanently open open/closed estuaries estuaries D Atten Nil ation 0Salinity4 00 Axis i 00 f o 00Area , A 60 Depth L4 TyolomnqaGreat Ke o o Mngazana Jujura Great Fish Keiskamma Group B Group C Group D Group E Msikaba Mkozi Group F XoraMbasheNqabaraNxaxoKobonqaba MtamvunaMzambaMtentuMzintlavaMntafufu MtatiKiwaneMpekweniShwele-ShweleOld Woman's o MncwasaGqunqeSihlontlweniQoloraGxara MpakoNgqwaraNgogwaneShixiniCebe MkweniMbotyiLupatanaMzimpunziGxwaleni MtakatyeMdumbiMtata MtanaNgculuraGqutywaBiraMgwalana MngaziLwandileNenga SinangwanaMapuzi MtentwanaMnyameniMgwegweSikombe Figure 6.2 CCA ordination of estuaries based on plant species presence/absence in the Ciskei and Transkei regions. speciesSpatial separation are shown. of the Environmental estuaries in relation variables to environmental include water variables column and depth, the distribution average salinityof plants and secchi depth. 66 Flagstaff Permanently open NMke Silaka flat r - Trans kei Hiuleka Nature Reserve Port St Johns Mangrove I Swamp Group C- forest Reserve MtamvunaMzambaMtentuMzintlavaMntafufu Owese Nature Mngazana Estuary J Wi I lowvale NqabaraNxaxoKobonqabaGroup B - Mangrove I Salt marsh e MtataXoraMbasheMtakatyeMdumbi Pedd Ciskei Group A - Salt marsh F IlodonPort Alfred GreatKeiskammaTyolomnqa FishKei River River Figure 6.3: A summary of the three groups of permanently open estuaries and associated plant betweencommunity the types estuaries found dominated in this study. by saltThere marsh is a andtransition those atcontaining the Mngazana swamp Estuary forest species. 67 Flagstaff TemDorarliv oDen/closed NMka Groùp F - Rieds, Transkei SilukaReserve Nareh\ : sedges and Swampforest ReserveNiuleka Natue Port St Johns MkoziMbotyiMzimpunziGxwaleni MnyameniSikombeMgwegweMkweniLupatana Willowvale6 Owesa Nature Reserve Group E - Reeds and sedges Mtentwana e QoloraNgogwaneGxara only LwandileMapuziNenga Ciskei ShixiniMpakoNgqwaraGqunqeCebe MncwasaSihlontlweniMngaziSinangwana F Ilodon Peddi Group D - Salt marsh, reeds and sedges ort Alfred L, BiraMgwalanaMtatiMpekweniOld Woman's Shwele-ShweleKiwaneMtanaGqutywaNgcul ura Figure 6.4: A summary of the three groups of temporarily open/closed estuaries and associated plant marshcommunity and thosetypes thatfound contain in this swamp study. Aforest. transition is shown between estuaries that have salt 68 6.4 DISCUSSION AND CONCLUSION The1993). characteristics Factors such of estuaries as geomorphology, are by definition salinity, dependent light attenuation on their andsurrounding depth were ehvironment (Cooperhighlighted et al. as important in theclassesinfluencing different based estuaries the on distribution the spatialwas more ofseparation macrophytes closely ofrelated plant in the tospecies. the Transkei Whitfield The region. difference classification Estuaries in the couldsystem be divided than the into geomorphologic 7 broaddistribution of plant species in ordination.distributionclasses proposed for the bywestern Harrison Cape et estuaries.al. 1999a; The1999b. geomorphologic Coetzee et al. classes (1997) couldshowed a explain the outliers in the similar pattern for plant resultingThenot temporarily describe in three the openfclosed geomorphologic changes in estuaries species classes showeddistribution. (lA, thelB and greatestThe 2) probable (Harrison variation cause et in al. was 1999a; due terms of size and morphology to the increase in1999b). mean annualHowever, this could brackishBureaurainfall of rainfall conditions, approximately data). i.e. This reeds,100mm is reflected sedges every in and120 the swampkm increase between forest in speciesthe species. Ciskei that and are Port associated Edward with(South freshwater African or Weather typesregionThe Transkei that (Steinke were region characteristic1995). is consideredThe transition of brackish to befrom the estuaries, more transition xeric such zonesalt as marsh between swamp plant forestthe community warm and the temperate and subtropical typesreed to and plant sedges, community was evident.assumedof the ichthyofuana,Harrison that due et al. to the (1a warm 999a;actual Indian1 mid 999b) point Ocean in theirof thisgyre survey transition that alsoaffects wasnoted the not thisregion apparent. transition between the Previous researchers have along the coast. In the case Mzimvubu and the thisMbashe boundary, Estuary,River. ratherMaree the thanboundary and beingWhitfield between a fixed (1998) point, the using temperate was records a transitional and of subtropical fish areaspecies between biogeographic in different the zones Great Kei and Mbashelocalities, estimated that would be at the theidentifiedEstuaries. plant community by In thisthis study.study types theThese and boundaries estuaries. data indicate ofThe transition thatonly theexceptions were biota between of estuarieswere the outlierGreatare distributed Keiestuaries and Mzimvubu Rivers for all according to local that have been associatedphysicalbecause conditions, ofwith its permanently unique whereas morphology openthe outliers estuaries and limitedimply that that intertidal have morphology mangrove/swamp areas. Harrisonalso plays forestet a al. role. (1999a;community The 1999b) types. Msikaba Estuary was also regarded This was floodplainclassthis estuary (3C). features. The as well Mngazana asThese the Mtentu floodplainsEstuary Estuary was have also as created classifiedbeing unique conditions separately and forclassified duethe establishmentto theseits unique two estuaries of geomorphology and the largest mangrove in a separate colonisedJujuraforest inand the by the study plant Mkozi region.community are two The temporarily typesestuary typical also closed ofhad permanently 8 estuaries out of the that, open 9 possible due estuaries to theirplant (mangrove unique community types geomorphology, have been associates and present. The submerged macrophytes). Interestingly, the Jujura was placed in a separate geomorphologic 69 class by storageHarrison capacity. et al. (1999a; Thus any 1999b). runoff Theflows catchment directly through of this estuarythe estuary is formed and keeps by a narrowthe mouth valley open that for has long a low intolerantisperiods adapted with of to frequentdaily these tidal intertidal inundation exchange. conditions and This this has (Adams system resulted et is al. mostlyin 1999).the colonisationclosed The mangrovedue toof itsthe small fern mud incatchment. banks the Mkozi by Z. ThisEstuary capensis estuary is that wascoastsSimilar an ofrelationshipsoutlier Australia. as this Evidence between was the hasgeomorphologyonly shown estuary that with certainand this plant species plant distribution community present. were types found are along associated the western with certain and eastern types increasecoincidedof estuaries, the more diversitye.g. with mangroves local of habitats physical with and the conditions speciespermanently foundrichness open in Australia.(Thom estuaries. et Localal. However,1975). variation This the wasin exact habitat apparent distribution was forfound the of to Ciskeispecies regionsnationaland Transkei hasbasis resulted estuaries (Section in thatregions4 and received 5). of The increased high variation botanical biodiversity. in physical importance Mangroves, environment scores salt when and marshes transition compared and between withswamp estuaries biogeographic forest onspecies a sharingplantare communityfound environments in the type same richnessat theregion. limit and, Theof their in botanical the environmental case importance of the estuaries tolerance rating with recordsand swamp competing this forest, as awith high high species species habitat with richnessrarity. the sameBy and habitatmanagementThe distribution requirements, strategies of estuarine there related is plants high to estuaries.geneticin relation variability Ato summary geomorphologic within of species dominant classes (Bryant plant has 1998).species important can implications be presented in using estuariesmangrovethe geomorphologic require or salt sufficientmarshes. characters; freshwater Both e.g., these Class runoff plant 2 tocommunityestuaries maintain are opentypes permanently mouthrequire conditions. regular open and tidal This are exchange. summarycharacterised Thus, of information by such either distributionphysicalis especially environment of important estuarine on in plants thethe distributionTranskei along the where ofSouth plants little African càn is known aid coast. the about understanding the estuaries. of the In overallfuture thetrends role in of the the lt could be expected that the southern KwaZulu- KwaZulu-NatalCooperNatal etregion al. (1999) upcoast to thepoint should Tugela out then that region be there a shouldtransition are similarities have zone similar between in geomorphology affinities the tropicalto that forof and the these subtropical northern two regions. Transkei regions. The region. Steinke northern andwith(1995) 5).the has tropical shown coast that ofthe Africa. most northernThese estuaries estuaries had namely high thenational St Lucia botanical Estuary importance and Kosi Bayscores have (Sections affinities 4 70 7:7.1 THE INTRODUCTION DEVELOPMENT OF A HABITAT INTEGRITY INDEX termsThe change which arein functional synonymous importance with integrity over timeinclude can habitat be used status as a andmeasure habitat of condition botanical (Turpie habitat etintegrity. al. 1999). Other fromthatAn ecosystem is past normal records forexhibits that or aerial system. integrity photos Habitat if, when for theintegrity subjected Swartkops was to determined disturbance,Estuary (Colloty using it retains etthe al. change the2000). ability in Habitat plant to recover coverintegrity towardover has time aalso state habitat(Pondolandbeen used integrity to - highlightTranskei) of as many the (Colloty conservation other et estuaries al. 1999). importance as The possible. case of estuaries studies This also above in ledthe necessitatedtonorthern some refinements Eastern the determination Cape with Province the final of the habitat7.2 THE integrity USE OF index A HABITAT tested at INTEGRITY the end of this INDEX section. TO DETERMINE THE EFFECT OF DEVELOPMENT ON THEEncroaching SWARTKOPS residential ESTUARY and industrial development and the increase in demand for freshwater threaten South diversity,highAfrican conservation estuaries. contains Instatus.a highorder numberAn to ensureestuary of plant theirmight communitycontinued have a high survival, types conservation or thereits state is astatus of need intactness ¡fit to isidentify a isreservoir adequate estuaries of highto that ensure species have a condition,continuedbotanical anfunctioning. condition assessment of The an can botanicalestuary be made over importance oftime. the Bypresent ratingcomparing botanicalsystem the can statuspresent be usedof condition an to estuary. assess to theThe changes past, botanical or in pristine the status can beTheinfluence used Swartkops as anthe indicator statusEstuary of hasof higher ecosystem the trophicthird largest status levels. areaas the of plants salt marsh are the along primary the South producers African and coastline their condition and exhibits will a varietyPlantand intertidal community of estuarine salt typesmarsh, plants not submerged (Baird found et in al.the macrophytes, 1986). estuary There include reeds, are mangrovessix sedges, different phytoplankton and plant swamp community forest. and types,benthic Macroalgae namely microalgae. species supra- notoccurMaintenance be in measured the Swartkops of habitat from available Estuaryhas long (Hilmer mapsbeen recognisedor et aerial al. 1988), photographs. as but the the essential area covered issue in by conservation this plant community and environmental type could typesthemanagement. variety which of they habitats. In addition,comprise Ecologically, the provide greater habitats estuarine the number for plants a large of differentare variety a source plantof faunal of community primary species production types(Davies in an1982, and estuary the Bally community the et al.greater 71 birds1985; that Whitfield utilise 1984; the marshes Adams foret al.food 1999). and breedingThese species (Adams range et al. from 1999). planktonic The ability and of benthic plants filterto improve feeders water to qualitymarshuses byin will theretaining provide marine pollutants aenvironment; more effective and excess for habitat example nutrients than mariculture, acan small have one recreationimportant (Daly and implicationsand Mathieson subsistence for 1981). many fishing. A beneficial comparison A large water salt of seagrassspeciesmaintaining was continued single higher large into thefunction versus many longernumerous small ifseagrass artificial small seagrasschangesbeds. However, werebeds madehas it was shown to laterthe thatsurrounding shown density that and theenvironment diversitysingle large of (Fairweatherarea.The Swartkops These developments1999). Estuary is surrounded have resulted by urban in a number and industrial of changes developments to the estuarine of the Portplants. Elizabeth These includemetropolitan obstructionphysicalThe objective elimination of ofwater this offlowstudy plant in wasthe community supratidalto determine types regions the as effectswell that as has of changes humanresulted toimpacts in the invasion physical on the by environmentextentterrestrial and plant distribution such species. as of the importancephotographs,estuarine plants score orthophoto in for the the Swartkops estuarymaps and under Estuary. the 'pristine'application These and effects of present a formula were conditions. assessedto calculate from the available comparative literature, botanical past aerial 7.2.17.2.1.1 Materials Assessment and ofMethods aerial photographs, orthophoto maps and past literature Thephotographsmaps, area aerial covered photographsand by maps the different published (Directorate plant in pastcommunity Surveys reports and types (Jacot Institute (ha) - Guillard was for Coastalmeasured 1974; Resource Baird from et 1:50 al. Management, 1986). 000 topographic These UPE) were and 3.0).andconverted the The area area into covered scaledcovered bydigital by the residential plantimages community (Hewlett-Packard and industrial types wasdevelopments Scanner measured 4C). andusing The constructions imagedigital analysisimages such were software as thenroad (AnalySiS calibratedbridges wherearea.was also To development estimatemeasured the fromhas past encroachedmaps cover (Fig. of this 7.1).onto plant Developmentthe community marsh. The has type, area mainly plant of supratidal encroached distribution marsh wasonto was assessedthe measured supratidal at six assalt sites the marsh areaofThe human functionalabove activities the importance mean on high the estuarineratingwater formulaspring plants tide (Section over mark time. (MHWST)4) was The applied formula and belowto includes the theSwartkops 2.5all estuarinem contour Estuary plant line. to show community the effect asphytoplankton.types the namely; area covered salt The marsh, extentby water reeds of theon and thephytoplankton slacksedges, tide benthic in community hectares, microalgae thus type allowing withinfound thein comparison the Swartkops intertidal with Estuarysand other and was plant mudflats calculated and community types. 72 a betterEstuaries perspective were rated on onthe a importance national basis of an using estuary. the functional Seven estuaries importance were rating selected and compared in order to gain from the Cape and KwaZulu-Natal7.2.2 Results regions and compared with the present botanical importance score of the Swartkops Estuary. The7.2.2.1 water Phytoplankton surface area of 135 ha was used as a measure of phytoplankton and extended from the mouth of causedthe botanicalestuary by development. to importance Perseverance rating,Changes Bridge this in area(16 freshwater km was upstream considered input of(water the to havemouth) quantity) remained (Fig. and 7.5, water unchanged Appendix quality despite Tablemay have 7.2). the affectedchangesFor use in impossibleimportancephytoplankton toformula predict production because, what withinphytoplankton as theyet, estuary. we have production These no way changes,may of estimating have however, been the under magnitude are pristine not included of conditions. this ineffect, the botanical as it is The7.2.2.2 area coveredBenthic microa!gaoby intertidal benthic microalgae was based on the extent of exposed intertidal mud and thesandbankssignificant botanical reduction in importance the estuary. in size formula This or change was (Fig. calculated 7.5,to the Appendix geomorphology to be 174Table to 7.2).180 of theseha. An banks average over value time. of The 177 scour ha was of oneused bank in lt was assumed that there has been no Esterhuysengenerally7.2.2.3 resultsSubmerged 1988). in the macrophytes deposition and Zostera creation capensis of a new Setchell bank on (eelgrass) the opposite side (Reddering and reachesEstuaryMacNae andof(1957) the covered estuary, found an the but area seagrass was of most15 haZostera abundant (Table capensis 7.1). in the Z. capensiswasintertidal abundant wasregions foundalong of theinthe the middleentire subtidal lengthand zonelower of the in reaches. the Swartkops upper In lowertheTalbot upper and and reaches middleBate (1987) reaches,of the studied estuary where the the itrewpopulation species on mud was dynamics banks. observed of Z.growing capensis on insandy the Swartkopssubstrata in Estuary contrast and to showedthe withinwinterthat the theand plant first summer is 6 sensitivekm of 1981the to estuary. indicatedflooding A andsignificantthe sedimentpresence but deposition.of small a thriving difference Thorough community was surveysobserved with up of tobetween seagrass 90% of thethe beds winterbeds during found area the coverageA surveyentire Z. ofof capensis the13.7 Swartkops ha andpopulation the Estuary summer from in thelateextent estuary 1984 of 16.1(Hilmer after ha heavy inet 1981al. 1988)flooding. (Table indicated 7.1).Recolonisation a complete of thedisappearance estuary by thisof the species was only apparent in August 1988 when about 4% of the 1981 population size had returned, covering 73 coveredapproximately byZ. capensis 0.6 ha (Table was 12.57.1) mostlyha (Table in the 7.1, mouth Figures region 7.1 and(Humer 7.2). et al. 1988). In this study the area Table 7.1: Summary of the characteristics of Zostera capensis foundSurvey in the Swartkops Estuary. biomassStanding - Productivity g.C.y1 Cover (ha) Comment surveyedTalbotMacNae and in 1981(1957)Bate (1987) 76- - 125d. w. g.m2 20- x 106 13.7-Increased15 16.1 from FluctuationsPristine due to floods HilmerEmmerson et aI. (1988) (1983) -todecreased 16040 - 0.6- floodSlowremovalBetween led recovery to complete1982- phase 1984 AerialAdams1996(pers. photographs and comm) Haschick -250 - 310 - -12.5 -tramplingRecovery hampered by 7.2.2.4Intertidal Salt salt marsh marsh pristinedevelopmentFor this condition study, took it for placewas intertidal estimated in the salt basin thatmarsh. of the the intertidalAerial Swartkops photographs salt Estuary marsh takencovered (Table in 7.2, 1939an areaFig. indicate 2).of 215This that ha would largebefore represent areas any of the UitenhageFig.intertidal 7.2). salt road marsh and (45to other ha) were roads lost and when bridges. the Swartkops MacNae (1957) and Redhouse described Villages the Swartkops were developed Estuary plants(TableIn 7.2,later years, smaller areas of marsh were lost to the solar salt works, the power station, the bridge,vegetationfound in salt the mapmarsh lower it wasoccursestuarine estimated mainly reaches, alongthat inbetween the 1957 north the Amsterdamhoek bank intertidal as far salt as marshthe and saltworks, Swartkops covered while 168 Village. ha.beyond Above From Redhouse theMacNae's railway Village period7.1).it extends From 1983 along later to 1987 mapsthe southern(Table and aerial 7.2). bank photographsSince approximately the construction the area10 km covered of from Settlers the by mouth theBridge intertidal ('Bar (N2 -Highway) None")salt marsh in in a 1974wasnarrow 166 there belt ha has for(Fig. the beentheintertidal Fishwater little salt change marsh Flats in region coveredthe area (Table 165 covered ha,7.2). the by reductionintertidal saltof 0.8 marsh ha was (165.8 due ha, to theTable upgrading 7.2, Fig.re of road 7.3). interchanges in In 1996 the 74 Motherwell Bar one

. N Brickfields Perseverance causeway Bluewater Bay\Amsterdamhoek Tidal limit

Despatch - Uitenhage road Rail and road bridges / Kwazakhele - Neave

Figure 7.1 The Swartkops Estuary showing the distribution of surroundingdevelopments. Past plant cover in the Swartkops estuary, before 1939

.1km. -4 C) Intertidal salt marshes Supratidal salt marshes Reeds Escarpment Terrestrial vegetation

Figure 7.2 The past plant cover of the Swartkops Estuary before 1939. Present plant cover in the Swartkops estuary, 1998 N

Bluewater Bay

Settler's Bridge

Redhouse Swartkops Village

Uitenhage Road Neave and Fishwater Flats

1km Intertidal salt marshes s Supratidal salt marshes Reeds Escarpment Terrestrial vegetation

Figure 7.3 The 1998 estuarine plant cover of the Swartkops Estuary. Table 7.2: Summary of the change in the area covered by intertidal salt marsh as calculated from availableand orthophoto maps, aerial maps photographs (1:10000) (Trig. Survey and Department of Environmental Affairs) Aerialsurvey photos and field Survey/Author Cover (ha) 215 currentEstimate MSHWM of intertidal area before any development at Comments fromAerialMacNae maps photos 1957 1939 - estimated 165.3 168170 roadPost-constructionPost and development railway bridges of of power Swartkops station, and salt Redhouse works, Uitenhage Village OrthophotoAerialJacotKaplan -photographs Guillard and maps Scott) (Hill, 1983 1974 - 166 -SettlersReduction Bridge in (N2),intertidal 1968-1 salt 974marsh after construction of TalbotandAerialOrthophoto photographs Bate maps 1987 19851996 165.8 165166 Reduction- due to further road construction (M19 to Supratidal salt marsh Uitenhage) estimatedprevious studies to cover (Table approximately 7.3). ForThe the40 area hapristine in covered extent or pre-development (Fig.by supratidal 7.2). Approximately salt condition, marsh was 31 supratidal ha measured of supratidal salt from marsh saltaerial was marsh photographs had and maps drawn in removalFishwateralready of been approximately Flats eliminated Sewage 4 Works, byha 1957of marsh Settlers because (Fig. Bridge 7.3).of developments (N2) and the (TableM19 bridge 7.3). toFrom Uitenhage 1957 to resulted 1997 construction in the further of

78 Table 7.3: Summary of the change in the area covered by supratidal salt marsh calculated from andavailable orthophoto maps, mapsaerial (1:10000).photographs MSHWM (Trig. Survey = Mean and spring Department high water of Environmental mark. Affairs) AerialSurvey/Source photos 1939 Cover (ha)40 CommentsEstimate of supratidal area before any development at 2.5 m fromMacNae maps 1957 - estimated 9 bridges,Village,contourPost development powerNeave station, industrial of salt Swartkops area works, Uitenhage Village and road Redhouse and railway OrthophotoJacot - Guillard maps 1974 1983 86 andPostRoad the construction Settlersconstruction Bridge of Fishwater(M19 (1 968-1 to Uitenhage) Flats974) Sewage Works (1972) 7.2.2.5 Reeds and sedges Aerial survey 1996/1 997 5 Further road construction and extension of Fishwater Flats providedstudy,The area estimates incovered reports of by theand reeds area from andcovered recent sedges colour by reedshas aerial not and been photographs sedges documented were (Table based nor 7.4). onidentified visual Dense presencein reed previous and in sedge reports.photographs beds For are this usuallyPerseverance(common found reed) in thecauseway is theupper dominant reaches (head speciesof of the estuaries estuary, in the whereSwartkops Fig. 7.1). the Table salinityEstuary 7.4 is and showsless extends than that 15 forfrom g.e. the RedhousePhragmites pristine condition Village australis to or until to reduced19576 ha inreeds 1983. the coveredcover Futher to approximately4.5floods ha andin 1997. quarrying 10 ha. Thereafter,in the channel a series and floodplain of floods andfor stone bank aterosion the head reduced of the the estuary cover Table(1:10maps, 7.4: 000). aerial Summary MSHWM photographs of =the Mean change (Trig. spring Survey in the high areaand water Departmentcovered mark. by reedsof Environmental and sedges Affairs)calculated and from orthophoto available maps Aerial photos Survey/Source Cover (ha) 10 Estimate of area before any development at current MSHWM Comments JacotestimatedMacNae - Guillard 1957from maps1974 9.510 Reduction- in cover after flooding events OrthophotoPresentCoetzee coveret maps aL 1997(1997) 1984 4.5 56 FurtherIncreasedReduction erosion bank in cover anderosion quarries after below November Perseverance 1996 floods causeway 79 7.2.2.6 Functional importance rating Thescoresee data Section over for thetime 4 forcalculations have the methodbeen ofsummarised theof determining functional in Fig. importance the 7.4. functional scores importance. are shown Changes in Table in 7.2 the of functional the appendix. importance Also In the pristine state the Swartkops Estuary had the TheFig.highest pristine 7.4. normalised condition functional(Fig. 7.4) representsimportance the score estuary (100) without with a steadyany development reduction in and score where over the time estuarine as shown in intertidalimportanceplants are salt assumed score marsh for isto the seenhave Swartkops in colonised the earlier Estuary all years available over of development,time. habitats. A major There withdecrease was large-scale a decreasein area elimination covered in the functionalby becoming supratidal less and Developmentsdevelopmentevident in subsequent started such as taking years. Swartkops place This within isand shown Redhouse the Swartkopsby the Villages, 49% Estuary reduction roads (pristine and in the bridges conditionfunctional and to theimportance 1939, power Fig. station score7.4). led once to the productiveplantremoval cover of submerged largeleads areas to a 6% macrophyteof supratidalreduction Zostera insalt the marsh. functional capensis In later importanceby yearsflood accounts(1939 score - present, (51for theto 45). lowFig. Theimportance 7.4) removal the gradual scores of the loss forhighly of1984 marshandChanges 1988. and in Presently,intertidal plant cover benthic the also most microalgae.alter important the functional botanical importance components of an in estuary the Swartkops on a national Estuary basis are when the intertidal compared salt to highEstuaryother importance estuaries covers aof score total different areafor the sizesof Olifants78 orha with compared Estuary other plantis to a the result community Mngazana of the large types Estuary area present. thatcovered covers For byexample, ansupratidal area the of salt615Quko marsh.ha. The rankingThein Mngazanathe (secondEastern Estuary place)Cape Province. inhas terms a high of In itsimportance its national pristine functionalconditionscore because importancethe Swartkops it has thanthe Estuarylargest it presently mangrovewould has have (third community had place) a higher (Tablepresent withinof7.5). estuarine this This group is dueplants of toestuaries. stillthe presentloss of area in the covered Swartkops by the Estuary, estuarine it is plants.still ranked Despite third, this, based because on its ofpresent the large condition area

80 Table 7.5: Functional importance scores ranked in decreasing order of importance for a number of South African estuaries. Normalised scores are also presented. Olifants Estuary importance score Functional 397402567 027 Normalised score 100 99 GamtoosSwartkopsMngazana 19981939(pristine) 203312604179936 857 90 704 23455178 GoukouQukoGrootKieskamma Brak 32303475366210783298 211215 8 250000300000 Q.C.)> 200000 Q)C) 150000 < X 100000 50000 rPristine 1939 r 1957 r 1974 r 1982 Ir 1983 r 1984 1988 Present Supratidal salt marsh D Intertidal salt marsh D Reeds I I Year I I Submerged Macrophytes Figure 7.4: The change in area cover x productivity values over time for the respective plant community types in the Swartkops Estuary. 81 The7.2.3 majority Discussion of plant community types found in the Swartkops Estuary have been affected by anthropogenic lossEstuary.development of intertidal As early within salt as themarshMacNae's estuary after (1957)basin. the construction Bridgesstudy, changes and of roadsthe in railway sediment have causedbridge deposition near major Swartkops changeswere noted Village.in theto have Swartkops The led to the Swartkopsmarsh.embankments Because Estuary of ofthis overthis, bridge therethe andlast has 40the been years. N2 Settlersa decreaseIn order bridge to in protect theled botanicalto riverthe removal front functional properties of both importance intertidal in Swartkops andscore supratidal Village of the and salt steeptoAmsterdamhoek the cliffs,retaining where walls area, no have intertidal retaining been area builtwalls occurred. up, were whereas constructed. the Bluewater In the case Bay ofwalls the wereSwartkops constructed Village, in areasan area adjacent of isplantsSmall-scale difficult and to overgrazing. anthropogenicdetermine the The amountimpacts effects of includeof area these orfootpaths impacts productivity andare nottrampling,lost recorded as a result littering, in ofthe these baitfunctional digging, activities. importance mooring The extensive of score, boats as in it uprootingpencilintertidal bait of (So/enmudflats the Zostera cyclindraceus). are ancapensis ideal habitat Extensivebeds, litteringfor bait bait organisms(plastic digging bags has such resultedcontainers as the in mud impactsand prawn discarded such (Upogebia as fishing trampling africana)tackle) and and and numerousfromThe saltthe marshmean footpaths highhas beenwaterin the divided neapsupra- mark intoand to twointertidal the plant mean saltcommunity high marshes. water types. spring These mark, are and the the intertidal supratidal marsh marsh that that occurs intertidal(Adamsoccurs above et species, al. 1999).the springbut Supratidal they high-tide are more salt watermark. marshsensitive species Theseto inundation may two have salt (Adams marshsimilar typeset salinity al. 1992,differ tolerance inAdams species ranges and composition Bate to that 1994). of SaIt industrialcommunitymarsh has development beentypes. affected This byis bypossibly the human reduction due development to of the tidal ease flow and at and whichsubjected the thesedrying to areas outhigher of are such pressures reclaimed areas. than for the residential other plant or oftoThe potentialnatural reed anddisturbance. habitat submerged for subsequentLarge macrophyte floods recolonization. have plant been community shown Floods totypes removeremove have thethe shown reedsriparian greater resulting plants variation andin bank scour in erosionarea the coverbanks and due loss activitiesdeposition.leaving in behind Thesethe Perseverance unstable banks are steep later area sided colonised have river altered banks by grassesthe where channel and there geomorphology,invasive appears plants to be such thuslittle assubsequentpreventing Acacia spp. reed sediment Quarrying removeestablishmentSenna the didimobtyra riparian in this plants regionare found that of theare in smallestuary.mostly isolated reeds, Alien clumpsinvasiveerode the in plants riverthe upper bankssuch reachesas and Acacia open of cyclops,theup areasestuary. Lantana for Largeinvasion camara floods by and alien species, thus removing a habitat previously colonised by reeds. 82 The submerged macrophytes have also shown variation due to floods, with little seasonal variation evident. periodicitySeagrassesIn its pristine (Talbot in morecondition, and temperate Bate the 1987) Swartkops climates haveEstuary stable would standing have had stocks a higher with variation ranking (secondoften correlated place) in to terms flooding of its presentthenational estuarine infunctional the plantSwartkops importancecommunity Estuary, thantypes. it itis Despite presentlystill ranked this has third,and (third because based place). on of Thisits the present islarge due area state.to the of lossestuarine of area plants covered still by Application7.24 Conclusion of the functional importance rating system identified salt marsh as the estuarine plant community estuary.thatprotection has Anyexperienced ofreduction salt marsh the in theirgreatest as these area loss areaswill dueaffect make to higherhuman a significant trophic development. levels contribution (Davies Emphasis to 1982, the shouldsecondary BaIly beet al.placed production 1985; on Whitfield of the the estuaryintertidal1984). The is benthic allowed most microalgae.important to remain botanical open, These thus areascomponents ensuring should regular incontinue the Swartkops tidal to flushing.function Estuary optimallySupratidal are theprovided salt intertidal marsh the saltareasmouth marsh have of the and theengineeringsuffered future, the the aregreatest supratidal more losses prone salt probably tomarsh development may because be the (i.e. they most Fishwater are vulnerable only Flatsperiodically plant Sewage community inundated, Works, type Neave and in with termsindustrial suitable of loss area). due In to further7.3 EASTERN developments. PONDOLAND ESTUARIES There7.3.1to be are estuaries.Introduction 45 rivers The that remaining enter the riverssea along are either the 150 ephemeral km of Pondoland or seep into coast. the Only foredunes 23 of thesealong arethe consideredcoast, while eithertemporarilyseveral off-road flow closed directly vehicles, with into five bridalthe being sea or overfootpaths. permanently cliffs (Plate The open. only 7.1). estuariesAll Whitfield these estuariesthat (2000) are easilydescribed are remote accessed 18 withof theseare access those estuaries limited protected asto withinestuaries.fishing the or Mkambati harvesting Nature of any Reserve. resources. These This estuaries has all contributed (Table 7.6) to are the mostly high conservation small and not status really of suitable these for 7.3.2See Section Materials 7.2.1 and for methodsthe method of determining the habitat integrity of an estuary. 83 7.3.37.3.3.1 Results Botanical surveys coveridentifiedBotanical for allassurveys estuaries.well as were species Fourteen conducted composition. plant in allspecies 23 Aerial estuaries were photographs found during in Februarythe were Pondoland used 1999. to calculate estuariesPlant community past (Table and 7.6) typespresent and were wereplant area)reedsrepresentative andand benthicsedges of three microalgae(8 species) of the seven(measured and swamp possible as forest exposed macrophyte (2 species). sand community and Phytoplankton mud banks)types namely; were (measured found mangroves inas all water estuaries. (4 surfacespecies), measuredmadeThe total up 15.2%,estuarine as intertidal phytoplankton surface sand area and measured formudflats, the Pondoland aswas water 10.9%. regionsurface These was area were approximately was the 61% dominant of the 342.7 total community ha. and Reeds benthic types and microalgae, insedges all of estuaries5.5%the Pondoland and has 6.3% shown estuaries. respectively. that plant The speciesFurther remaining wereanalysis plant related (Sectioncommunity to the 6) freshwater oftypes, the species i.e. components mangroves composition ofand the swampof estuaries, the Pondoland forest i.e. covered reeds, geomorphologysedges and swamp that forestoccur species.within this This region. is because of the higher meanTable annual7.6: List runoff of plant and species changes found in in the estuaries of the Pondoland region. SpeciesAvicenniaAcrostichum marina aureum Forssk. L. Vierh. VerbenaceaeAdiantaceaeFamily PlantMangrove community associate type JuncusBruguieraCyperus kraussii gymnorrhíza textiis Hochst Thunb. (L.) Lam. JuncaceaeCyperaceaeRhizophoraceae ReedsMangrove and sedges PrioniumPhragmites serratum australismauritianus (L. (Cay.) f.) Kunth.Dreg Steud. ex Mey. J uncaceaePoaceae ReedsReeds and and sedges sedges StenotaphrumSporobolusRhizophora virginicusmucronata secundatum (L.) Lam. Ku (Walt.) nth. Kuntze PoaceaeRhizophoraceae ReedsMangrove and sedges associate HibiscusTyphaStrelitzia capensistiiaceus nIcola! L. (Rhorb.)Regel and N.E. Koern. Br. MalvaceaeTyphaceaeStrelitziaceae SwampReeds forest and sedges 84 Plate 7.1: The Mkambati River is not considered to be an estuary as it flows directly into the sea over aseries of waterfalls. 7.3.3 2 RegIonal functional importance highestshowEstuaries that community canthe permanentlybe compared richness open on(number a estuariesregional of plant basis had community the using highest the typesfunctional functional present). importance importance The smaller rating. scores. closed The They data estuaries also in Table had have the 7.7 functionalAlthoughless available the importance. Msikaba habitat Estuary and this, is coupleda large (15 to the ha) lack permanently of tidal exchange, open estuary resulted in this in lowregion, plant-community it had a low richness. lt has a steep valley formation and there is little area available for estuarine plant becauseclassifiedcolonisation, of as the temporarilyhence large the delta low open areas score. estuaries. at Thetheir Mbotyi mouths These and estuariesthat Mnyameni are colonized both Estuaries have by high reeds. are functional also exceptions importance that scores have been 85 Table 7.7: Present (1998) community richness and functional importance rating of estuaries found in Permanentlythe Pondoland open region. estuaries Estuaries are shown are ranked in bold. in decreasing order of functional importance.Estuary Community richness importanceFunctional Normalised score MbotyiMtentuMntafufuMzamba 45 score 222911649468 88917169 100354659 MgwegweNkodusweniMzintlavaMnyameni 435 108421114815 833 9270 22192430 SikombeMkweniButshaMsikaba 43 34 830903244492 89 MtentwanaKwanyanaMzimpunziMkozi 234 23 3850255271 815 457 NtlupeniMpahlaneMpahlanyanaLupatana 34 1 434527618 233 MtolaneMyekaneMgwetyana 23 204660842865 021 52%Photographs, of the estuaries taken in the 1961, area were covered available by the for different the Pondoland plant community region. These types and,photographs hence the showed functional that for notdecreaseimportance, as great in functionalhasas in not those changed importance estuaries over subjected duethe lastto the 33 to loss yearshigher of (Tablemangrove levels 7.8).of anthropogenic or Twenty reed cover. eight disturbances, Thispercent decrease of estuaries such was, as however,showed in the a theCapeMtentwana head and of KwaZulu-Natal the Estuary estuary. where On regions a reed national cover(e.g. basis,Swartkops, had been the Pondoland lost Nhlabane due to region theand construction Mlalazi (Table Estuaries). 7.8) of has a small a Thehigh dam exceptionconservation and golf was course status the at unchanged.with7.3.3.4 a greater Botanical percentage rarity of of Pondoland estuaries either estuaries showing an increase in functional importance or remaining Thesmalllt isMtentu butimportant it is and the Msikabato only identify estuary Estuaries estuaries in the have Easternthat uniquehave Cape unique geomorphology where features the mangrove or and species are fern also composition. Acrostichum the only two The aureum South Mkozi African occurs. Estuary is estuaries where the rare Mkambati palm, Jubaeopsis caifra is found. This species is not part of any estuarine 86 increasesplant community. the importance However, of thesethe estuaries, palms are even only though a few theirmetres presence from the is highnot reflected water mark in the and functional their rarity importance score. Table 7.8: Past (1961) and present (1998) functional importance scores of selected estuaries along the South African coastline. Estuaries are ranked in decreasing order of importance. found Estuary functionalThe normalised importance scores as are a percentage.calculated for Pondoland each estuary estuaries in order are to shownillustrate in thebold. change in Past functional importance functionalPresent Normalised score % Change MsikabaMgwegwe 28101scores 665710 importance 44929 270score 826218 388218 ZinkwaziMbotyiMtentukwanyana 11721151480719268 833 22889117935117169 833 2025 100 908684 101416 0 MkoziMkweniSikombeMzintlava 4244233853830 527 2338538304244 527 100 0 MyekaneMgwetyanaMpahlanyanaMpahlaneMzimpunzi 1 527434 660842 1 527434 660842 100 0 MzambaMtolaneNtlupeniNkodusweni 5010843 827 204866 4910843 468 204866 100100 97 030 MngazanaLupatanaButshaMnyameniMntafufu 329685 2024838 134 6 0961 562 312604 2914815 116 3 9031 618 7699966473 -27-24 -36-6-4 SwartkopsMtentwanaMlalazi 224042280 357 4253 128816182 666 1815 42576511 -89-58-43- 37 7.3.4 Discussion and conclusion Nhlabane 120585 13666 ThestatePondoland study is very showed estuaries similar that to are what although nationally their thenatural important area state covered asmay they by have thehave been.estuarine been These the plant least estuaries community impacted also types overhave time. wasunique small,Their species present the suchinPondoland the as permanentlythe mangrove region. Thisopen fern is estuaries.and due fringe to the Themangrove geomorphology mangrove communities. stands that onlyfound The allows in mangrove these small estuaries areas physiognomy for usually mangrove isoccur unique colonisation as ato double the row or, in some cases, a singte row of mangrove trees. In Australia and Japan 87 where such rare stands occur, Souththese typesAfrican of coast mangroves have developed have been into termed large fringe complex mangrove communities forests. with Mangroves found elsewhere along the a large number of associated Japanrequirelowerspecies. (dough juvenile a Thesehigh and degreerecruitment larger Andrews ofcommunities protection rates1981). and as are are has more more been resilient susceptible shown to in disturbance, similar tó disturbance. cases whereas found Thus, in fringe regionsthese Pondoland of Australia estuaries and mangrove forest exhibits southerntheKwaZulu-Natal Pondoland KwaZulu-Natal areaNature become Conservation to Mntafufu part of a ServicesEstuary larger marine justand north the protected Oceanographic of Port area St Johns. stretching Research This fromstudy Institute Mpenjati highlighted have Estuary proposed the in that 7.4conservation NATIONAL importanceHABITAT INTEGRITY of the Pondoland OF ESTUARIES estuaries from a botanical perspective. databasewhichBotanical information was importance constructed was available. and for habitat 274 To South integrity aid the African rapidwere estuaries.determinationdetermined This for of wouldthe botanical remainder help identifyimportance of South South andAfrica's African habitat estuaries estuaries integrity for a usedthat7.4.1 remain to determineMaterials unimpacted andthe numbermethods and the and regions type of they impacts occur occurring in. Those in estuaries South Africa. that have been impacted could be aerialstate.Habitat photographs,The integrity area covered was maps determined by or the literature different by calculatingand plant compared community the functionalwith types recent importancewas information. measured of anThe from estuary difference the oldest in its in past availablefunctional and present changeddeviationimportance werefrom scores giventhe naturalwas a score calculated condition of 100, as orwhile a as percentage thefor otherhabitat estuaries and integrity this wasthat of an subtractedhave estuary. changed, Allfrom estuaries the loo percentage and thatexpressed have change not is as relativedeviationapplied scores fromto the theas ranges pernatural the in botanicalcondition.Table 7.9. importance TheseChange scores in rating scores where (Section over tested time, 4, usingSection positive a range4.2). percentile test and assigned or negative, are regarded as a Table 7.9: The habitat integrity scores applied to the ranges for percentage deviation from natural scores. deviation fromPercentage integrity score Habitat natura'0.5-7.67.7-1415-30 0 100204060 31-90 88 lO inreducedExample: supratidal by Over 5 salt ha. the marshOther last elevenchangesand 1.7 years hain plantreduction the coverarea in covered were submerged a 0.25 by mangroves reductionmacrophyte in in intertidal thearea Mngazana cover. salt Togethermarsh, Estuary 1 these.5 has ha have beenreduction habitatEstuary.resulted integrity inThis a reduction was score expressed of in 60 the (Table functional as a 6%7.9). deviationimportance from score the fromnatural 317 condition 935.2 to and 312 the 604.05 estuary for thethus Mngazana obtained a 7.4.2The raw Results data and list of impacts applicable to estuaries is shown in the Appendix and database. The communitySeries)information spanning types. used Most forthe the midof thecalculation to informationlate 1980's. of habitat was For obtainedthe integrity Ciskei fromis and the the Transkeichange Green in estuaries, Booksarea covered (CSIR, this changebyEstuaries the different was of measuredthe plant Cape for wereaTable thirty-year used 7.10 toindicates period. measure Forthat past estuaries of theplant 124 cover. such estuaries as the used Swartkops in this study,and St 44 Lucia, estuaries aerial (35%) showed no change in photographs taken in 1937 score(7%)area coverin of Ciskei. 60, over 4 had The time a remainder score with habitatof 40, of 12theintegrity had Transkei a scoresscore estuaries of of 20 100. and were Of 8 thesehad distributed a 40score (91%) as follows;were 12 had a habitat integrity of 10. Ten of the Transkei estuaries found in Transkei and 3 caseestuariesshowed of mangrovesan showed increase a (Tabledecrease in either 7.10). reedin plant There and cover sedge was over a orsimilar swamptime trenddue forest to for removal thecover. Ciskei forTwenty-six agriculture (35%) or wood of the utilization Transkei in the estuaries where 43% (7) showed a inthosedecrease the removalwhere in plantplant of salt covercover marsh, overhad astimebeen seen (Table lost in due the 7.10). toGreat road The Fish, construction estuaries Mgwalana, that at hador Mtati near the and theirlowest Gqutywa mouths. habitat Estuaries. These integrity roads Thescores resulted were while7.10).greatest the In reduction theBira case and ofMpekweniin theplant Keiskamma cover Estuaries occurred Estuary, were in theimpacted large Keiskamma, areas by ofroad salt Bira, and marsh Mpekweniresidential have been and developments. Kiwaneconverted Estuaries intoInvasive croplands, (Table Acacia exceptionintrees the hadWestern replacedof the and Mdlotane 30%Eastern of Estuarythe Cape reed or all beds KwaZulu-Natal had inlow the habitat Kiwane Provinces integrity Estuary. scores(Table The remainderas7.10). a result These ofof thea32 reduction estuaries124 estuaries in with plant occurredthe cover dueBulungulaEstuaries to residential found (-41%), developments in Keiskammathe Transkei in (-30%), and the CiskeiCape Kiwane systemsthat (-30%)received and and farming the Mtentwana lowest in the habitat KwaZulu-Natal(-57.3%). integrity Highly score estuaries. productive of 10 included plant the Thecommunityestuaries. regional types Agriculturerating such of the as has saltCiskei resulted marshes, and Transkeiin themangroves greatest region andreduction has swamp highlighted in forest area agriculture(34%)have been covered aslost a byfrommajor the these threatestuarine estuaries. to these plants (Appendix - Table 1 list of impacts). An example of this is the Nenga Estuary which is rated 179th in South 89 alsoAfrica. been Not used only doesfor crop the production. town of Coffee The BayBulungula occupy Estuary the floodplain, but the islands within this system was the only system where there has been a have time3.5loss ha inwith ofmangrove mangrovea loss of cover 1.7 cover. ha due of The reedto a Mtentwana naturalbed. This drought wasEstuary due event had to the(Knight the construction greatest pers. comm.decrease of 1999). in functional This system a weir and golf course that resulted importance over has lost all in the 14% reduction in total plant cover of this estuary. Table 7.10: The habitat integrity scores of 124 South African estuaries. A change over time, while lower scores reflect a degree of change to the estuary. score of 100 represents no Estuary 100 Change % Estuary 60 Change % Habitat integrity Estuary 40 Change Estuary 20 Change Estuary 10 Change % GqwaraGqunqeFreshwaterBlue Krans Poort 0.0 GreatCebeBot/Kleinmond KeiFish -0.6-2.9-3.7 GouritsHartenbosDuiwenhoks2.5 Heuningnes -11.1-11.1 Gqutywa Bululo13.6-9.0 Bira Elsies -15.4 Buffels25.825.615.8 BulunguluButsha Oos Gamtoos -31.3-36.0-41.1 47.1 Ku-MpenzuKu-BhulaKu-amanzimuzamaGxwaleniGxara 0.00.0 MhlathuzeMbasheLupatanaKromJujura Oos 2.16.13.56.72.3 Mtati MtataMnenuMbotyiMgwalana -13.1 Kobonqaba10.513.8-8.5-9.1 KnysnaHluleka MdumbiKwanyana -22.9-21.0-16.5 KeiskammaMdlotaneKeurbooms17.822.6 KiwaneKabeljous -30.3-53.342.770.1 MapuziLwandileLwandilanaKwa-SukaKwa-Nyambalala 0.0 Ngqusi\lnxaxoMzimvubuMzambaMtanaMtakatye -2.7-6.1 UilkraalsZinkwaziSteenbras2.17.6 RooielsNhlabane -11.5-10.2 MnyameniMntafufu14.3 -9.9Mpako Mkomazi9.1 Mtambanê -20.3-26.8-23.6-28.9 MncwasaMlalaziMgwegweMdloti17.4 Mpekweni -42.0-42.5 31.081.638.0 MkoziMhlangaMgwetyanaMenduMbhanyana 0.0 MngazanaQoraQoloraPalmietNqabara -2.4-6.1-2.2 4.01.9 StSinangwana OldNgqinisaMtentuLucia woman -20.4-15.7-24.8 NtlonyaneNgculuraNenga29.515.8 Mtentwana Msikaba -43.8-49.5-57.340.637.4 MtolaneMpandeMpahlanyanaMpahlaneMkweni 0.00.0 Wildevoëlvlei -0.5 XoraUmgaziSwartkops -16.0-17.7-29.3 SiyayaSeekoeiSilvermine Tyolomnqa -35.386.550.949.3 MzìntlavaMzimpunziMyekaneMtongaMtumbane 0.0 NgqwaraNgomaNgogwaneNgadlaNcizele 0.0 Shwele-ShweleShixiniNtlupeniNkodusweniNkanya 0.0 TshaniTongatiSundwanaSikombeSihlontlweni 0.0 Zalu 0.0 90 7.4.3scaleThe habitat asDiscussion they integrity have changed assessment little indicatedover time thatand thehave Ciskei high andhabitat Transkei integrity estuaries scores. are Estuaries important found on ina nationalthe northernsystemsEstuaries wouldTranskei are not dynamic are be particularlyvalid systems in reporting unimpacted. with greatthe importance temporal changes.or health Usingof an estuary once-off (Turpie measurements et al. in rating 1999). However, botanicalphotographsthe area covered importance and bybotanical the over different time importance can plant then community can indicate be measured habitat types canintegrity. at anybe measured time Habitat if information integrity from available scores is available. mapsof 100 and The(i.e. changeno in estuariesplantchange) community were in KwaZulu-Natal calculated types in forthese where a number estuaries floods of can Ciskeihave alter not and plant changed Transkei cover over andestuaries. the botanical last The 30 importance years.areas coveredThis by is 10%in by contrast the (Riddin different to This1999).Estuaries was due in to the the south change Eastern in submerged Cape have macrophyte shown a large cover variation in the small in functional temporarily importance open Kabeljous scores over and time. whenscoresSeekoei the over Estuaries. estuaries a twenty-year wereFor both closed period of these and (Freckelton salinity estuaries and 1 999).there water Thiswas currents wasbetween due were to30 reduced.rapid and 45%growth (Adams variation of submerged et inal. habitat 1992; vanintegrity macrophytes (CollotysubmergedHattum 1998).et al. macrophyte 2000). The cover variation resulted in plant in a cover8% variation was thus in dependentthe habitat integrityon the type score of estuary.over a 45 The year inherent period In the large permanently open estuaries such as the Swartkops Estuary, the variability in droughtstabilityRiddin ofevents. 1999), larger resultingHowever, estuaries is ifhas less individual been change documented estuaries over time are elsewherewith monitored natural (Branch fluctuationsover time, and Grindleya only threshold evident 1979; of during natural Coetzee large variation et flood al. 1997; or managementcausecould bea change set. Changesshould in the be habitatin altered land integrityuse to not or waterexceed scores. abstraction the threshold could of alternatural the variation. functioning The of habitat an estuary integrity and scoreswould If these changes altered the natural threshold of a system, the inancan the estuary be most used toimportant as modification. a tool estuaryto measure This in hasSouth the already status Africa. beenof Changing an usedestuary, insalinity understanding but can levels also in be thethe used lakenegative tosection determine effects of the of Stdevelopment Lucia the sensitivity of P.Potamogeton Estuarypectinatus (northern diespectinatus out KwaZulu-Natal) when colonises salinity much reaches also ofinfluences the half lake that sectionthe of seawatersubmerged of the andSt macrophytes.Lucia is replaced Estuary by When(Ward Ruppia the 1976, cirrhosasalinity Taylor is and low,1991). theZosterareduced entrance capensis by of 19% rivers. (Taylor due Quibell to 1991).development (1996) Potamogeton has in shownthe catchment. pectinatus that the meanThisis then has annual limited resulted runoff to areas in to higher the of freshwaterSt and Lucia more system input,variable has i.e. salinity beenat 91 dynamicsconditions of thewith submerged longer periods macrophytes of near marine of the Stsalinity. Lucia ThisEstuary. increase in both salinity and variability affects the includesystems.The botanical a Richardsonmonitoring importance function (1995) rating stated to determinesystem that canan theadequate thus effects be used measureof management to identify of conservation important plans. With estuaries importance the use as ofwellshould the as habitat alsothreatened theplantintegrity status community andrating, future threatened type regeneration that isor thréatened sensitive capacity estuaries the of thesemost could isplants the be mangroves.within identified. the Transkei ThisIn the warranted case (Section of the further 8). Transkei investigation region, the into estuary,verticalA monitoring aerial for example programme photographs the smallof ofthis a temporarily region.type would The open benumber easy estuaries toof implement,surveys of the would, Western as all however, that Cape is requiredProvince be dependent is alternate a time on sequence betweenthe type of botanicalestuariesclosed and importancefound open in conditions the rating KwaZulu-Natal duemore to frequently insufficient region. and Theinformation thus Kwazulu-Natal could on have the change aestuaries greater in variationplantare under-represented community in plant cover than overin the time.

92 88.1 DISTRIBUTION INTRODUCTION AND STATE OF TRANSKEI MANGROVES ThreeapproximateMangroves million area hacover occur of approximately15.5 along million the haeast one along and quarter thewest coasts ofAfrican the of world's Northcoasts tropicalAmerica, (Blasco coastline. etSouth al. 1998). America, They Mangrove extend Australia over communities and an Asía. aredetritalbirds important (Snedaker food systemschains 1978). (Chapman in stabilisingThey are 1984, acoasts, source Snedaker providing of primary 1978; a nurseryRobertsonproduction habitat 1996).with andenergy refuge transfer taking place through for invertebrates, fish and (571ha)(0.05%Along the ofEstuaries eastAfrica's coast total).in KwaZulu-Natal.of South The largest Africa mangrovesConsiderably occuroccur lower inat 37mangrovethe estuaries Mhlathuze tree and (652cover cover ha) is approximately found(Riddin at 1999)the Mngazana 1 and 688 St ha Lucia differdistributionEstuary from (145 those limits. ha) in inThe thethe size northernformer (area Transkei. hemisphere cover) and This tropics,species is evidence with composition the of aexception natural of South decline of the African Kositowards Baymangrove thesystem southern communities that has exampletagaltropical and affinities Mozambique, Lumnitzera and contains racemosa Tanzania Avicennia trees. and Kenya. The marina, latter Bruguieratwo species gymnorrhiza, are only found Rhizophora along tropical mucronata, coasts, Ceriops for wasTheincorporated Transkeian independent region into South borderinghomeland Africa the from and east 1963became coast until ofpart 1976 South of whenthe Africa Eastern it becamebetween Cape athe Province.republic. Great Kei After Political and 1994, Mtamvuna instability, Rivers poor it was re- Plumsteadoninfrastructure estuaries 1984, were and 1990, lacklimited of Plumstead tofunds a few have (Dye et limitedal. 1977, I 989a, research 1978, 1 989b, 1983a, activities 1991; 1983b; and in the WooldridgeEmmerson region. Consequently and1974, 1977). ecologicalEstuaries werestudies McGwynne 1992; thatof excludedmangroves of Ward from and in this botanicalSteinke region. in research 1982.The most for recent more thanaccount 11 yearsof distribution and little andis known extent about of mangroves current structure in the region and state is Themanagedpoles mangrove for animal land communities development enclosures along (MolIprogrammes the et Transkeial. 1971). and region poorIn addition, soil are conservation threatened smothering chieflypractices deposits by inthe of river siltchopping resultingcatchments of treesfrom has poorlyto led make to thatanUntil increase often recently exceeds in suspended in manythose countries,optimum sediment for mangroves loads. tree survival This were sediment and considered growth is then (MolI to trapped be et wastelandaI. 1971,by mangrove Steinke (Bryant communities1995). 1998), particularly in at a rate economically advancing countries rapidly developing their coastal lands. In Europe and Asia, for example, 93 Isipingo,industriesmost mangroves Mgeni (Dierberg and have Mkomaziand been Kiattisimkul destroyed Estuaries 1996). or and modified Withinhave been toKwaZulu-Natal, make replaced way for by housing,mangroves industrial, roads, residentialhave harbours been or removed agriculturaland aquaculture from the industrialareas.For the One effective development of the protection richest have mangrove of removed mangrove communities approximately stands, scientists in South200 ha andAfrica of managersmangrove occurred requiretrees in Durban (MolI information etBay, al. 1971).where on the harbour structure and thisand section function the offollowing the community are addressed: types and their sensitivity to disturbance (Steinkethe distribution, 1995; Tam size etand al. composition 1997). In of mangrove stands along the coast of former Transkei; the proportionreasonsrates of colonisationfor of change the mangrove in and mangrove removal community cover of trees andthat on occurs a regional in declared scale; conservation areas. 8.28.2.1 MATERIALS Field surveys AND METHODS collectionMangroveAll 76 estuaries 1996 stands (Scale were were 1:5000) surveyed identified and in usingSurveysat least aerial twoand photographs fieldMapping visits 1961during (Institute and the 1974 period for Coastal(Scale December 1:10 Resource 000)) 1997 andManagement to August from the 1999. field Arnoldsystemsurveys. and through Mangrove De Wet a combination (1993).species composition of transects and and the digital extent image of cover analyses. of each Species species nomenclature were identified was for basedeach on 8.2.2The area Mapping (ha) covered and ¡ma by ge the analysis mangrove communities was measured using 1:50 000 topographic maps and imagedigitalaerial photographs.imagesanalysis were software thenThese (analySIScalibrated were converted and3.0). the These areainto measurements scaledcovered digital by each images were plant verified (Hewlett-Packard community through type field wasScanner assessments. measured 4C). Theusing cover.observations.Mangrove cover This and information species composition was then used in each to determine estuary were the directioncompared and with rate Ward of change and Steinke's in mangrove (1988) 8.2.3Line intercept Mangrove transect state measurements were used to assess the condition or state of each of the mangrove communities. In past surveys in Transkei, mention has been made of the impacts such as wood harvesting 94 andHowever, high sediment the degree loads to in which the rivers the communitiesaffecting the arestate being or condition affected of has the never mangroves been quantified. in this region. Transects were alongpropaguleeach 20each m still longtransect visible), and to5 replicatecomparejuveniles transects the(< I statem in wereheight)of the measured different and trees mangrove in (>each 1m mangrovein communities. height) werestand. Speciesidentified Seedlings included and (part counted ofall mangrovemangrovesIdeally, the fern stateand Acrostichum mangrove of mangroves associates aureum. is monitored such as using the freshwaterpermanent mangrovetransects visitedHibiscus on tiliaceusa monthly L. basisand for a the transect.wasminimum not possible. This of informationtwo Tree years density (Ward was then wasand usedSteinke inas conjunction1982).a measure Due ofwithto statethe aerial inaccessibility by photographscounting the of somenumber(1:10 Transkei000) to determine estuaries, the this of individuals along a number8.3 RESULTS of individuals per unit area in each estuary. in8.1).Mnyameni,Mangroves Transkei No new Mzimvubudifferedwere occurrences recorded from and thatof Bulungula instands of14 past of were the Estuaries.surveys 76 recorded estuaries (Fig. in 8.1). the surveyed, remainingThere has with estuaries. been complete an increaseThe loss total of inextent trees mangrove evidentof mangroves area in the in This amounted to a loss of 17 ha of mangrove area (Fig. WardtheXoraeight estuaries, (4%),ofand the Steinke Mbasheestuaries, i.e. no (1982), (11%)distribution i.e. the thisand Mtentu increaseNxaxo trends (50%), (7%)from represents Estuaries.Mzintlavaa north aversus total (15%), These ofsouthern 17.6 Mntafufuincreases ha perspective. over (20%), were the randomlyMtakatyepast Compared eleven (17%),distributed years. to theMtata The survey amongst (19%), larger by wasTheestuaries observed. loss ini.e. total Mtentu, mangrove Mtakatye, cover Mntafufu, for the sameMbashe period and Mtatawas approximately showed the greatest 17 ha. increaseThus, a netin mangrove gain of 0.6 area. ha implementedEstuariesareaFrom occurestimates have in byprotected inhotelshown this ownerssurvey areasincreases (Fig.and along residents8.1 in the mangroveand Mtamvuna, Table along 8.1), coverthe Mtentu estuariesapproximately probably and (Hewson Mbashe attributed 48 ha pers. Estuaries.(18 %)comm.). of the The Thecurrent Xora coastal andmangrove Nxaxoareas to conservation measures includedandThe Rhizophoraonly inmangrove conservancies mucronata species are (Tablerecorded not yet 8.1). part during Theof proclaimed themangrove surveys conservation fern include Acrostichum Avicennia areas. auroum marina, was Bruguiera recorded gymnorrhiza for the first totaloftime the estuaryduring coastal this surface town survey. of area). Mbotyi The fern (Fig. dominated 8.1) and thecovered middle approximately and upper reaches 1.3 ha ofof thethe Mkoziestuary Estuary, fringe (5515 km% ofnorth the 95 OverallPreviously there thehas Mtentu been little Estuary change was in recorded mangrove as species having compositiononly Bruguiera in thegymnorrhiza different estuaries in the middle (Table reaches. 8.1). mangroverecordedgymnorrhizaHowever, juveniles tree ahad number occurring been of this ofremoved Avicenniaspeciesin 75% from ofand marinathe the Rhizophora estuaries Nxaxo trees Estuary were mucronata.while found. Bruguieraby floods (Ward gymnorrhiza and Steinke occurred 1982). in 65 % of the Previous research indicatedAvicennia that marina Bruguiera was the most common This study HibiscusestuariesHighest treetiliaceus surveyed. densities (Table of 8.1).2 594 tree.ha1were recorded in the Mngazana Estuary followed by the Mntafufu (1 The Mtamvuna and Mzamba Estuaries were only colonised by B. gymnorrhiza and sizewas402Mtakatye trees.ha),foundestuaries between Estuary Mtatasuch the ofas(210 the areathe trees.ha1)same Nqabara covered size andEstuarybyhad the the162 mangrove Mbashe (9trees.ha1. ha) had (174 stands Thelow trees.hat) Mntafufutreeand densitiestree (Table densitiesEstuary, 8.2).of 74 12(r=0.2, No trees.ha1, hain significant p<0.05).size, hadwhereas correlation Moderate a high the tree treefringedensity densities mangrove of 1 (between 402 stands trees.ha1. 121 and - 210intertidalThe trees.ha1, Mbashe, islands Xora,Table that Mtakatye,8.2). were also Mtata colonised and Nxaxoby mangroves. Estuaries This were resulted characterised in high by densitiesmangroves.Mtamvuna,Densities (between of andMangrovesdead Kobonqaba20 trees - 26 recordedfoundtrees.ha1, Estuaries ¡n protectedas Table stumps (Table 8.2). areas were Field8.2). suchgreater surveysTree as removal orthe showedequal Mtentu hasto that thatand had tree ofXora the the removal largest Estuariesliving treesno impact longer had in thehighon occurs theMdumbi, juvenile fringe in MngazanaEstuariesthese estuaries in Estuary, which as mangrove hadno tree juvenile stumps survival densities wereis threatened ofobserved. between include 32 and the 603 Mdumbi, trees.ha1. Mzamba, Kobonqaba and Mtamvuna. The other 12 estuaries, with the exception of the regenerationthanThese 50 estuaries % of potentialthe receivetrees ofbeing nothe form standsremoved. of conservation is limited. No seedlings protection or juveniles and large-scale were found tree in theseremoval estuaries has resulted and the in more 1J) O h % I % vrlim Mamut 1 0.4 25 Q2 - Mkozi estuary Ìvkirai 1 0.4 0.15 O. - Port Edward Mìanrni 3 0 0 0 M1u 1 0.4 2 0.7 + Port St Johns kiî1lava 1.5 0.5 1.75 Q6 + Miafi4ù 10 3.5 12.4 5 + Eastern Cape Minhi I Q4 O O O Mvaa 150 54 145 54 - Kei Mouth Mkte 7.5 3 9 3 + MInh 1 0.4 0.5 0.2 - Mata 34 12 42 16 + Rihzla 3.5 13 0 0 0 Xxa 16 6 165 6 + 125 4 14 5 + Nt 9 3 &5 3 - Port Elizabeth N,«y1isi 14 5 15 5.5 + Kdmp1z 6 2 3.5 1 -

Figure 8.1: A map of the Eastern Cape Province showing estuaries that support mangrove communities.Present area (ha) and percentage of total area cover for the region is given. The past area cover values were taken fromWard and Steinke (1982). Key: + = increase in area cover, O = no change and - = decrease in mangrove cover. Table 8.1: A comparison of species found in this survey compared with past surveys, including ascomments conservation on possible protection. reason for changes in composition and total area covered, as well Mtamvuna Estuary (WardB. gymnorrhizaSpecies and Steinke present 1982) in past literature B. gymnorrhizaPresent in this survey A total of five trees in Comments ProtectedConservation status Mzamba B. gymnorrhiza B. gymnorrhiza estuarytheA total midestuaryupper of reaches three reaches trees of theof in Unprotected MnyameniMtentu gymnorrhizamarina B. gymnorrhiza marina B. gymnorrhiza 8. None areSmallharvestingknownCause found A. marina possiblyofon loss the nottrees due to NatureUnprotectedMkambati reserve Mzintlava B. gymnorrhiza gymnorrhiza mudflatsIncreasereaches in thein stand mid cover inaccessiblebutUnprotected, MntafufuMzimvubu A. marina B. gymnorrhizagymnorrhizamarina, R. mucronata None gymnorrhizamarina, R. mucronata scouringLossIncrease possibly by infloods duestand to cover butUnprotectedinaccessibleUnprotected, MngazanaMtakatye andA. marina, B. gymnorrhiza R. mucronata gymnorrhizamarina, R. mucronata A. andmarina, B. gymnorrhiza R. mucronata gymnorrhizamarina, R. mucronata coverIncreaseDecrease due to in inharvesting mangrove mangrove UnprotectedUnprotected MtataMdumbi andA. marina,marina B. gymnorrhiza R. mucronata A. marina gymnorrhizamarina, R. mucronata coverIncreaseDecrease due to in inharvesting mangrove mangrove Unprotected Bulungula A. andmarina, B. gymnorrhiza R. mucronata None mouthdroughtmangroveComplete closure that losscover resulted of due toin Unprotected XoraMbashe gymnorrhizaA. marina and B. A. A.marina marina B. B.gymnorrhiza gymnorrhiza coverIncreaseNo evidence in mangrove of change CebecommunityDwesalocalProtected Nature and by NqabaraNxaxo A. A.marina marina and B. A. marina,marina B. gymnorrhiza IncreaseNo evidence in cover, of change with ProtectedUnprotectedreserves by Kobonqaba A. gymnorrhizamarina A.R. marinamucronata offoundtreesB. Losstreesgymnorrhiza and due R. tomucronata harvesting juvenile Unprotectedcommunitylocal 98 Table 8.2: Tree density of respective mangrove species found in the Transkei estuaries. Mntafufu Living Dead Heightlm Total Trees ha1 RhizophoraBruguieraAvicennia gymnorrhizamarina mucronata 256201749 40 04 363154 220735174 256205789 AvicenniaHibiscusMngazana tiliaceus marina 952152 148 0 289 0 811152 1100 1 402 152 HibiscusRhizophoraBruguiera tiliaceus gymnorrhiza mucronata 436141754 8578 0 602 32 0 489230141 2 594 141521832 AvicenniaRhizophoraBruguieraMtakatye marina gymnorrhiza mucronata 357710 20 0 14 08 104785 559710 AvicenniaMtataHibiscus marina tiliaceus 89 o 65 o 16 o 138 o 154162 o HibiscusRhizophoraBruguiera tiliaceus gymnorrhiza mucronata 42 o8 o6 o 1 47 o8 48 o8 AvicenniaMbashe marina 141 23 12 152 210164 HibiscusRhizophoraBruguiera tiliaceus gymnorrhiza mucronata 102 o 97 o 0o5 45 5o 5o AvicenniaMzamba marina o o o o 174 o HibiscusRhizophoraBruguiera tiliaceus gymnorrhiza mucronata 5o 0oQ 0o 5o 5o AvicenniaBruguieraMtentu marina gymnorrhiza 1815 20 15 4 16 0 201510 AvicenniaKobonqabaHibiscusRhizophora tiliaceus marina mucronata 85o 9o 80o 95o 17 5o HibiscusRhizophoraBruguiera tiiaceus gymnorrhiza mucronata o oo o o 17 o 99 Table 8.2 continued. Living Dead Heightlm Total Trees ha1 AvicenniaRhizophoraBruguieraNxaxo marina gymnorrhiza mucronata 1487 5 15 0 14 27 95 03 102 14 5 AvicenniaHibiscusNqabara tiliaceus marina 62 O 12 O 8O 66 O 121 74 O HibiscusRhizophoraBruguiera tiliaceus gymnorrhiza mucronata O O O OO O BruguieraAvicenniaXora gymnorrhizamarina 117 91 2031 1511 5675 718674 HibiscusRhizophora tiliaceus mucronata O O O O 157 O BruguiéraAvicenniaMdumbi gymnorrhizamarina 10 O 15 O O 1 24 O 25 O HibiscusRhizophora tiliaceus mucronata O O O O 25 O BruguieraAvicenniaMtamvuna gymnorrhizamarina 4O 4O 0O 4O 5O HibiscusRhizophora tiliaceus mucronata O O O O 5O AvicenniaBruguieraMzintlava marina gymnorrhiza 5723 20 40 5919 5923 HibiscusRhizophora tiliaceus mucronata O O O O 82 O 8.4 DISCUSSION AND CONCLUSION expected17With ha no have that major beenthere developments lostwould in 4be estuaries a occurringnegligible while in change thereTranskei was in mangrovecompared an increase coverto theof 17.6 overrest haoftime thein 6in South estuaries the study African over region. coast, the However,last it was eleven years; therefore a net increase of 0.6 ha (no evidence of overall decline). Four estuaries showed no change 100 andMangrovesin mangrove Avicennia previously cover marina in the haveoccurred 11-year been in lostperiod. 17 inestuaries the No Mzimvubu new but occurrences are River now founddue of mangroveto in excessive 14. Stands stands bank of were Bruguierascour recorded. due gymnorrhízato a high wereresultedincidence inundated in of the floods, for mouth a five while of month the mangrove Bulungula period stands (Knight Estuary in pers. the closing Bulungula comm. and 1998). because Estuary Consequently ofhave back been flooding Jostthe trees thedue mangrove todied a drought. stands This and have communitiescontainedsince been all harvested inthree the speciesMnyameni leaving (A. only EstuarymarIna, tree have Brustumps. guiera been This completelygymnorrhiza estuary wasremoved and one Rhizophora offor five wood estuaries mucronata).leaving that dead previously Mangroves tree stumps. Wardestuaries,The development and Steinkesuch as of(1982)the large Mngazana had mangrove observed and stands Mntafufu, both isBruguiera restricted have extensive gymnorrhiza by the naturalintertidal and geomorphology Avicenniafloodplain marinadeltas of that anin thisarea. support system. Some TheMngazanamangrove foliage treesand on theseMntafufu in the trees form Estuaries are of complexcurrently testify riverine grazed to the forests.denseby cattle. form The A ofbrowsehigh mangrove tree line densities occurred that occur that on inwere the these trees recorded two at estuaries. in the approximatelySnedakerFringe mangrove 1974). 1 .5 These m, communities while trees the are upper are adapted different canopy to aremainedto lower the riverine freshwater intact. mangrove input andforest narrow mentioned channel above geomorphology (Lugo and estuaries.(Medinatiiaceus. and These Areas Francisco estuariesstill available 1997). had This forlow colonisation typetree densitiesof mangrove by and mangroves communityusually no are mangrovewas limited found by associates inthe the steep other geomorphologysuch 14 Transkei as Hibiscus that has Themangroveled fringe to a lackmangrove fringe of floodplain communities communities habitats. with are theOther highest exception mangroves at risk, of St with found Lucia the in andlow South Mhlathuzetree Africa density could estuaries in these also (KwaZulu-Natalestuariesbe considered having coast). a Theloweredin overallnature sustainable reserves.protection Further statusyield. ofremoval mangroves of mangroves in Transkei within was the low estuaries with only south 18% ofof thethe Mzimvubumangroves River being is found areexpectedpresent usually inin selected thethe fringeMtamvuna, and mangrove this Mzamba, has communitiesaffected Mtakatye, mangrove as Mtata,most regeneration are Mdumbi, unprotected Mzintlava as there and is andeasily a lowKobonqaba accessible. percentage Estuaries. Mature of juveniles trees This lepidopterastockinhibits to the produce future(Dandouh-Geubas enough generation propagules of et propagules al. 1997) that can andas saturatemangrove keep the the colonisedstands seed predatorscan banks only survivestabile. such as ifCopicing thethere coleoptera is wassufficient only and evidentparent dueconservationin four to estuaries,the high of levelsmangrove namely: of use Mbashe, areas of these in Mtakatye,the systems, Mdumbi, Nxaxo with Mzamba little and or Mngazana,and no Mtamvunarecruitment and Estuariesonly observed by Avicennia are (no of juveniles). particular marina. concernThe 101 areasThepropagules mangrove and is almost to fern, the permanentlynorthAcrostichum is unlikely openaureum, as (Harrisonfew was suitable only et al. foundestuaries i 999a; in the iexist. 999b). Mkozi The Possible Estuary. Mkozi Estuary colonisationThe future has distribution largeof the intertidal fern ofin factorandestuaries geomorphology. that to could the south threaten No could major the include fern's developments existencethe Mbotyi isor and thesettlements Mzimpunzi expansion occur Estuariesof forestry around as from the they Mkozithe have adjacent Estuary similar Mbotyi mouthand the River dynamics only anelevatedcatchment extended sediment to period, the Mkozi loads back River that flooding cancatchment. affectcould theoccur Impacts mouth and usuallydynamicsresult in associated the of drowningthe estuary. with of forestry theIf the fern. mouthinclude remains runoff that closed contains for southwardsseenMangrove in the species overallalong theincreasefound Eastern in Transkeiin dominanceCape coast.are mostly of These Bruguiera primary species gymnorrhiza colonisers are particularly ofand intertidal Avicennia dominant mud marina andin estuaries sandflats. in estuaries found This futhernear is to onlythémentioned southern found in mostspecieslo of thelimit over 37 of estuaries theira 20 distribution.to 30 (Ward year periodand World Steinke (Zakir wide Rhizophora1982),1996), fourbut along ofmucronata which the areSouth usually found African inreplaces Transkei. coast thethis Estuaries above- species is mostimportancethat have complexity a ofhigh these indensity terms two estuariesof of this succession species in terms alongare of the themthe Mngazana Transkei being the andcoast. only Mntafufu riverine Estuaries. forest community This elevates that have the the al.Comparedis between 1998), Transkei toloo mangrove 000 systemsand 200 systems appear000 km2, in insignificant.North with America,the greatest South proportion America, contained North Africa in Indonesia and Austral-Asia (42 550 km2),(Blasco Brazil et lt is estimated that the present mangrove cover in the world Thevariety(13 mangroves 400 of km2) mangroves andon the Australia easttypes and and(11 west 500their Africankm2) associates (Blasco continent, when et al. excluding cover 1998). measurements The those wide found range areon in Madagascar,made area estimates(Blasco are et isal.estimated due 1998). to the appearsannum,to cover becauseapproximatelyinsignificant of tree (Blasco 54 removal 000 pers. ha. and Incomm. expansionAfrica 1999). with ofestimated This agriculture, does rates not the mean of loss loss thatof between mangroves the South 1 500 inAfrican tothe 2 Transkei 000 mangroves ha per region SaegnerMacNaeshould be 1963.and ignored. Bellan Secondly, They (1995) should they suggested are be at protected the that southern mangroves because most foundof limit their ofalong unique their the distribution species east coast composition (Saegner of Africa et areas al. describedthreatened 1995). by withbePresently over-utilisation a consideration mangrove (wood for ecosystems the harvesting). mangrove world-wide estuariesThis increases are in valuedthe theTranskei. asconservation a timber resource, importance and offor such the contribution systems and they must communitiesandmake nurseries to the stabilisation surrounding for invertebrates of the coastlines mangroves. and fish. and The Anthe fisheconomic creation and invertebrates of evaluation land, filtration ofprovide mangroves of runoff, a protein inas Bintuni wellresource as Bay, providing for Indonesia, rural habitats indicated that undisturbed mangrove forest is worth US$ 4 800,0O.ha1. This was based on the economic 102 protectionvalue of the and ecosystem fisheries. services Compared the to mangrove this the market communities value ofprovide, mangrove, such timber as coast is only stabilisation worth US$ storm 3 600,00. environmentslossesha1 (Ruitenbeek have hasadversely been 1992). highlighted affected The importance fish by recruitment the lossof mangrove of andsuch led systems systems to a decline in to North the in estuarinefisheries America in andand these surroundingthe regionsPhilippines. (Sheridan These coastSouth1997; andAfrica. Gilbert due With to and agriculture no Janssen large-scale activities (1998). fishery Subsistence that associated dominate and thiswith recreational region,any of theSouth fishermen mangrove African predominantly mangrovessystems along are use theconsidered estuariesTranskei to in Althoughbeactivities, more there important mangroves was no as net havea wood change been resource. inlost mangrove completely cover, from through three estuaries. a combination Any reduction of natural in events mangrove and humancover was theirshouldalso distribution reflected be the infocusand the there habitatof future is a integrity lackconservation of suitableof these proposals. habitatestuaries. for The colonisationConservation Transkei mangrovesof of additional the mangroves are estuaries at the is southerly importantdue to the limitand limited of Thisfornumber the protected northern of permanently area area would of the openinclude Transkei estuaries the coast Mtamvuna with would intertidal andincrease Mzamba regions. the conserved Estuaries The future asarea proposal well of asmangroves theof a unique Marine by Mkozi 5%Protected to Estuary 23%. Area thatpriorityReserve. contains need With the to the mangrovebe increasedset for thefern. demandremaining The Mtentu for mangroves. crops, Estuary water is alreadyand land protected for development, within the the Mkambati value and Nature conservation

103 9 GENERAL CONCLUSIONS AND RECOMMENDATIONS attainedcanThe berequirement used by countries in decision-making for an in importanceEurope that and ratingare setting 90% has management urbanised arisen due (Blake to objectives. the 1991), need Withforwhich accessible 0% is notpopulation likely scientific in growthAfrica, information theonly being that Transiresourcesdemands ei areas forand resources theas theyprotection areby anunderdevelOped ofincreasing natural ecosystems human and populationthere have is little become will available continue. crucial. information The This management study on targeted the rivers of thewater or Ciskeiestuaries. and TheseestuariesThemajor included ofobjective the microalgae,Ciskei of this and study Transkei. mangroves was toAdditional reviseand swamp the plant botanical forest. community Inimportance the types previous were rating botanical incorporated formula importance and into apply the ratingit formula.to the indicatedinclusion(Coetzee ofaset productivity al.the 1996, area (ha)1997) the component relativethe contribution importance was retained. of theof the plants Aerial different to photographs secondary individual production wereplant acommunity valuable was not sourcetypes included. could of information With be the verifiedfromOnce which the in 92the the estuaries field. area covered were surveyed, (ha) by the the plant functional community importance types could of the be Ciskei determined. and Transkei These estuaries areas were could then be determined.estuariescovered by had reeds. extensive This wassalt marshtrue for or the mangrove majority areasof the and,estuaries. thus, high However, functional the largeimportance permanently scores. open lt was expected that functional importance would be low, as most estuaries were small and estuaries,andThe plantconcept communityshowed of botanical that type functional importance rarity. The importance wasstudy extended on (area the Pondoland xfurther productivity to includeestuaries, value) species waspart inadequateof and a Rapid community Reserve to describe type estimate richness botanical for appliedandimportance. rarity) to thewere Traditional Ciskei included and measures inTranskei the overall ofestuaries conservation assessment and successfully importance of botanical highlighted(species importance. diversity, importance The richness,revised of estuaries rating habitat system basedrichness was on functionalTherelating reasons importancethe for distribution the botanical as well of the asimportance plantsthose thatto theof had estuaries phy a diversecal environment. in the or rareCiskei assemblage Basedand Transkei on theof species regionsplant species orwere habitats. described composition, by the Theestuariescouldmangroves. characteristic Thisbe dividedplant region community intois a thosetransition types that between werefor the permanently permanently the warm temperateopen open versus estuaries and those subtropical were that intertidalwere biogeographic temporarily salt marsh closed. zones and and forestEstuaries.both north permanently of In the permanently Mrigazana open and open Estuary. temporarily estuaries The closed temporarily the mangroves estuaries closed showedoccurred estuaries divisions north in theof atthe Ciskei the Great Great were Kei Kei characterised Estuary and Mngazana and swampby salt marsh and reeds. Salt marsh occurred because of the high salinity and wide intertidal and supratidal 104 zones.Macroalgae These estuarieswere also were common. characterised Reeds and by sedgesover wash occurred from the north sea of and, the Greatthus, had Kei highRiver salinity. and reeds, sedges characterisedtheand physical swamp forestenvironment by a occurredhigh diversity (MAR north and of of plant morphologythe Mngazana types. This and Estuary wastemperature) also where evident resultedthey in replaced the in fish a unique assemblagesthe salt group marsh. of that estuaries Variations were in Althoughuniqueimportance afor rating each of an index of estuary the should different should summarise types also of be estuariesinformation, highlighted. (Maree the This factors and has Whitfield been or components achieved 1998; Harrison in that the determine botanical et al. I 999b). theimortance overall creationisrating related as of theto the management components habitat integrity thatof resources makeindex upthat shouldthe shows rating also the are have effects identified. a monitoring of development Secondly, function. an as importance wellThis as has natural been rating change.achieved or index This in that the theDevelopmentwas last demonstrated sixty years, within using comparedthe Swartkops the change to the Estuary inNhlabane functional basin Estuary hasimportance reduced that had over the its functionaltime functional in the importance Swartkops importance byEstuary. reduced almost halfby 80% over in largelake,half that thebrackish timeweir whenhas reed divided acommunity. weir thewas system constructed The effects into a infreshwaterof this little system or no lake management (Riddin and a temporarily1999). were The evident Nhlabaneclosed inestuary the was study anwith estuarine onloss the of a PondolandharvestingThe greatest ofestuaries. threatmangroves. to Thisthe CiskeiNo small new andregion mangrove Transkei had the stands estuaries highest were densityis foundagriculture ofwith unimpacted almostin the floodplains no estuaries gain in mangroveand in Southunsustainable Africa.area in the threatenedRhizophoralast eleven years.mangrove mucronata, A further systems two conservation species are those that haveconcernin the been southern is thatcompletely harvestersregion removedof the are Transkei. targeting from three These Bruguiera estuaries. are fringegymnorrhiza The most and hascommunities1m reduced in height thethat was number cover low compareda ofsmall adults. area toSeedling andmangroves are recruitment easily where accessed harvesting was affected by harvesters. does as notthe takedensityThe place.intense of mangroves Thus, rate ofthe harvesting remaining less than mangrovecommunitiesOther threats forests haveinclude such a limited the as proposed those regeneration found dune at theminingcapacity. Mntafufu at Copicingthe andNxaxo Mngazana was Estuary only Estuaries.evident(Wavecrest). in larger Mining more of complex the dunes will eastriver.result coast These¡n a physicalof mangroves Africa. disturbance are important and possible as they mouth exist closureat the southern due to the most need limit for of water their abstractiondistribution fromalong the the lt is not known whether these are pioneer or climax communities and how resilient they fisherieswillFuture be to (andevelopmentfurther important impacts. ecotourismof agricultureThe value attraction) ofand mangroves industrial is also centresin not terms well in of understoodthe sustaining interior of inthe thisthe subsistence studyregion. region and will recreational increase pressure on the available resources. The large estuaries have been shown to be important as they are 105 toannualusually be upgraded runoff,characterised these and eitherrivers by more thewill Mzintlavabespecies targeted or or habitats. firstMsikaba for waterBecause Rivers abstraction. have of their been large Currently earmarked catchment the for Lusikisiki theareas construction and Water high Scheme mean of is becauseHowever,dams. This water there is inevitable wouldare unused have in this todams be region pumped such as as increased tothe the Magwa required industrial Dam sites. near and Magwa Lusikisiki.agricultural Dam This wasdevelopment dam constructed is not isconsidered foreseen. to supply viablethe teastudiedMsikaba plantations. and and through MtataFortunately, Estuaries. a process the Department of either a rapid of Water or intermediate Affairs and determinations, Forestry have initiated the environmental studies on waterboth the In the Mtata River study 12 other estuaries in the surrounding area will also be Asreservepermanently mentioned, will be theopen established larger and rivercontain for systems these salt marshes estuaries. will be targetedor mangroves. for water The use. potential Most ofthreats these oflarger freshwater estuaries reduction are extendedwheninclude the mouthperioda change closedof inundation.in salinity during gradients aThis drought has andoccurred period. mouth The in closure. other mangroves South This Africanhaswere already back-flooded estuaries, occurred such and in as drownedthe St. Bulungula Lucia after and anestuary basedmaintenanceMgobezeleni on these ofEstuaries.case base studies flow Mangroves that and maintains past canecophysiological onlysalinity tolerate gradients studiesca. five and onmonths keeps the mangrove theof submersion. mouth species. of the Thus, estuary the open allocation can be and 9.1The FUTURE dynamic RESEARCHnature of estuaries and the influence of this on conservation importance needs further apparentTheunderstanding. KwaZulu-Natal in terms Thisof estuaries the applies need requirefor not adaptive only more to the managementattention botanists as thesebut of water.to estuariesother fields were as well.not adequately This need representedis particularly in regions.havethe analyses. a high Also, number Thisthis regionwould of important hasaid thethe testingestuaries,greatest of number theas ithypothesis is theof estuarine transition that the lakeszone northern suchbetween as KwaZulu-Natal St. the Lucia subtropical and region Kosi and Bay. shouldtropical classificationaThe number Cape ofestuaries discrepanciesof the plant should community withbe surveyed regard types to as species in the this past region. identification information in needs the past to beliterature. updated This for accuracy.would clarify There the are 106 Adams,IO REFERENCES J.B. and Bate, G.C. 1994. 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-s -s Appendix Table -General estuarine information with a list of activities or impacts occurring on the estuary Estuary Code Province Region Classification Information Impacts or activities Berg (Groot) 0W 15 Western Cape Cool temperate Permanently open Moderate Bilanhioto NS 12 Kwazulu/Natal Subtropical Temporarily closed Poor Bira CSE 20 Ciskei Warm temperate Temporarily closed Nit Bridge, embankments, bait digging and grazing on floodptains Blind OSE 42 Eastern Cape Warm temperate Temporarily closed Poor Blinde CSW 26 Western Cape Warm temperate Temporarily closed Nil Bloukrans CMS 26 Eastern Cape Warm temperate River mouth Nit Blue Kraus CSE 24 Ciskei Warm temperate Temporarily closed Nit Small weir, trampling and rubble Boboyi NS 18 Kwazulu/Natal Subtropical Temporarily closed Poor Boknes CSE 6 Eastern Cape Warm temperate Temporarily closed Poor Bokrarnspruit CW 29 Western Cape Warm temperate Temporarily closed Poor Bot/Kleinmond CSW 13 Western Cape Warm temperate Estuarine lake Excellent Bree 05W 22 Western Cape Warm temperate Permanently open Moderate Buffalo CSE 41 Eastern Cape Warm temperate Permanently open Poor Buffets CW 3 Western Cape Cool temperate Temporarily closed Moderate Roads, golf course and mine dump Buffets Oos CSW 11 Western Cape Warm temperate Temporarily closed Moderate Buffets Wes CSW 1 Western Cape Warm temperate Temporarily closed Poor Bululo TS 61 Transkei Subtropical Temporarily closed Nit Causeway, rubble and grazing Bulungulu TS 34 Transkei Subtropical Temporarily closed Nil Mangroves have been lost due to drought conditions between 1993 - 1997 Bulura 05E 48 Eastern Cape Warm temperate Temporarily closed Nit Bushmans OSE 7 Eastern Cape Warm temperate Permanently open Moderate Butsha TN 28 Transkei Subtropical Temporarily closed Nil None - within Mkambati Nature Reserve Cebe TS9 Transkei Warm temperate Temporarily closed Nit Reed areas on the west bank used for grazing. Cefane CSE SI Eastern Cape Warm temperate Temporarily closed Nit Cintsa OSE 50 Eastern Cape Warm temperate Temporarily closed Nil Ounge CSE 49 Eastern Cape Warm temperate Temporarily closed Nil Cwili CSE 58 Eastern Cape Warm temperate Temporarily closed Nit Damba NS 23 Kwazulu/Natal Subtropical Temporarily closed Moderate Duiwenhoks CSW 23 Western Cape Warm temperate Permanently open Moderate Durban Bay NS 63 Kwazulu/Natal Subtropical Estuarine bay Good Eerste CSW 6 Western Cape Warm temperate Temporarily closed Moderate Elands CMS 36 Western Capo Warm temperate River mouth Poor Elandsbos OMS 29 Western Capo Warm temperate River mouth Nit Elsies Western Cape Warm temperate Temporarily closed Nil Fafa NS 34 Kwazulu/Natal Subtropical Temporarily closed Moderate Freshwater Poort OSE 23 Ciskei Warm temperate Temporarily closed Nit None Gamtoos OMS 48 Eastern Cape Warm temperate Permanently open Good Formal agriculture on floodplain, abstraction of water from tributary and recreational fishing Goda OSE 36 Eastern Cape Warm temperate Temporarily closed Nit Goukamma OMS 12 Western Cape Warm temperate Temporarily closed Poor Goukou CSW 24 Western Cape Warm temperate Permanently open Moderate Gourits 05W 25 Western Cape Warm temperate Permanently open Moderate Gqunqe TS 10 Transkei Warm temperate Temporarily closed Nil Grazing and bait digging Gqunube OSE 46 Eastern Cape Warm temperate Permanently open Poor Gqutywa OSE 21 Ciskel Warm temperate Temporarily closed Nit Grazing and alien vegetation (Opuntia sp) Gqwara TS 1 Transkei Warm temperate Temporarily closed Nit Reed areas used for grazing Great Fish OSE 15 Oiskei Warm temperate Permanently open Good Bait digging, bridges and alien vegetation, informal settlements Great Kei 05E 59 Transkei Warm temperate Permanently open Moderate Roads, embankments and stipways at the mouth and road across salt marsh Groen OW 7 Western Cape Cool temperate Temporarily closed Moderate Groot Brak OMS 3 Western Cape Warm temperate Temporarily closed Good Groot Oos OMS 37 Western Cape Warm temperate River mouth Poor Groot Wee OMS 23 Western Cape Warm temperate Temporarily closed Moderate Gwaing OMS 6 Western Cape Warm temperate Temporarily closed Poor Gxara Transkei Subtropical Temporarily closed Nit Gxulu OSE 35 Eastern Cape Warm temperate Temporarily closed Nit Gxwaleni TS 60 Transkei Subtropical Temporarily closed Nit Haga-haga OSE 54 Eastern Oape Warm temperate Temporarily closed Poor Hartenbos CMS I Western Cape Warm temperate Temporarily closed Moderate Heuningnes CSW 19 Western Cape Warm temperate Permanently open Moderate Hickmans CSE 38 Eastern Cape Warm temperate Temporarily closed Nil Hlaze CSE 43 Eastern Cape Warm temperate Temporarily closed Poor Hiozi CSE 37 Eastern Cape Warm temperate Temporarily closed Nil Hluleka TS 50 Transkei Subtropical Temporarily closed Nil Causeway at head of estuary Hout Bay CW 27 Western Cape Cool temperate Temporarily closed Moderate lntshambili NS 25 Kwazulu/Natal Subtropical Temporarily closed Moderate Jujura TS 15 Transkei Warm temperate Temporarily closed Nil Bait digging Kaalmans CMS 9 Western Cape Warm temperate Permanently open Poor Kaba NS 9 Kwazulu/Natal Subtropical Temporarily closed Poor Kabeljous CMS 47 Eastern Cape Warm temperate Temporarily closed Moderate Farming in upper reaches of catchment and residential development along west bank of estuary Kandandhlovu NS 6 Kwazulu/Natal Subtropical Temporarily closed Poor Kariega CSE 8 Eastern Cape Warm temperate Permanently open Good Kasuka CSE 9 Eastern Cape Warm temperate Temporarily closed Poor Keiskamma CSE 26 Ciskei Warm temperate Permanently open Poor Grazing, boating, bait digging, alien vegetation Keurbooms CMS 19 Western Cape Warm temperate Permanently open Good Kiwane CSE 29 Ciskei Warm temperate Temporarily closed Nil Alien vegetation (A. cyclops) Klein CSW 16 Western Cape Warm temperate Estuarine lake Good Klein Brak CMS 2 Western Cape Warm temperate Temporarily closed Poor Kleinemond Oos CSE 14 Eastern Cape Warm temperate Temporarily closed Poor Kleinemond Wes CSE 13 Eastern Cape Warm temperate Temporarily closed Moderate Klipdrif CMS 43 Western Cape Warm temperate Temporarily closed Nil Klipdrifsfontein CSW 20 Western Cape Warm temperate Temporarily closed Poor Knysna CMS 13 Western Cape Warm temperate Estuarine bay Excellent Kobonqaba TS 7 Transkei Warm temperate Permanently open Nil Removal of mangroves, bait digging and boating (slipways and boat houses) Koega CSE 4 Eastern Cape Warm temperate Temporarily closed Poor Kongweni NS 13 Kwazulu/Natal Subtropical Temporarily closed Poor Koshwana NS 24 Kwazulu/Natal Subtropical Temporarily closed Poor Kosi NN 21 Kwazulu/Natal Subtropical Estuarine lake Excellent Kowie CSE 10 Eastern Cape Warm temperate Permanently open Good Krom Oos CMS45 Eastern Cape Warm temperate Permanently open Excellent Krom Wes CW 31 Western Cape Cool temperate Temporarily closed Poor Ku-amanzimuzama TS 35 Transkei Subtropical Temporarily closed Nil Reed harvesting Ku-Bhula TS 27 Transkei Subtropical Temporarily closed Nil Ku-boboyi NS 4 Kwazulu/Natal Subtropical Temporarily closed Poor Ku-Mpenzu TS 26 Transkei Subtropical Temporarily closed Nil Grazing Kwa-Makosi NS 30 Kwazulu/Natal Subtropical Temporarily closed Poor Kwa-Nyambalala NS Kwazulu/Natal Subtropical Temporarily closed Nil Kwanyana TN 35 Transkei Subtropical Temporarily closed Nil None Kwa-Suka TS 29 Transkei Subtropical Temporarily closed Nil Kwelera CSE 47 Eastern Cape Warm temperate Permanently open Poor Kwenxura CSE 52 Eastern Cape Warm temperate Temporarily closed Nil Langebaan Western Cape Cool temperate Estuarine bay Lilyvale CSE 31 Eastern Cape Warm temperate Temporarily closed Nil Little Manzimtoti NS 48 Kwazulu/Natal Subtropical Temporarily closed Poor Lottering CMS 28 Western Cape Warm temperate River mouth Nil Lourens CSW 7 Western Cape Warm temperate Temporarily closed Moderate Lovu NS 47 Kwazulu/Natal Subtropical Temporarily closed Poor Lupatana TN 21 Transkei Subtropical Temporarily closed Nil None Lwandilana TS 47 Transkei Subtropical Temporarily closed Nil Crop production on floodplain and reed harvesting. Lwandile TS 48 Transkei Subtropical Temporarily closed Nil Bait digging Maalgate CMS 5 Western Cape Warm temperate Temporarily closed Poor Mahlongwa NS 41 Kwazulu/Natal Subtropical Temporarily closed Poor Mahlongwana NS 42 Kwazulu/Natal Subtropical Temporarily closed Poor Maitland CMS 50 Eastern Cape Warm temperate Temporarily closed Nil Manzimtoti NS 49 Kwazulu/Natal Subtropical Temporarily closed Moderate Mapuzi TS 44 Transkei Subtropical Temporarily closed Nil Housing on floodplain Matigulu/Nyoni NN 12/13 Kwazulu/Natal Subtropical Permanently open Poor Matjies CMS 20 Western Cape Warm temperate Temporarily closed Poor Mbango NS 19 Kwazuiu/Natal Subtropical Temporarily closed Poor Mbashe TS 25 Transkei Subtropical Permanently open Moderate Hydroelectric scheme Mbhanyana TS 27 Transkei Subtropical Temporarily closed Poor Mbizana NS 10 Kwazulu/Natal Subtropical Temporarily closed Poor Mbokodweni NS 50 Kwazulu/Natal Subtropical Temporarily closed Moderate Mbotyi TN 14 Transkei Subtropical Temporarily closed Poor Causeway at head of estuary, crop production on floodplain leading to a reduction in reed cover. Mcantsi CSE 34 Eastern Cape Warm temperate Temporarily closed Nil Mdesingwana NS 35 Kwazulu/Natal Subtropical Temporarily closed Poor Mdlotane NN 8 Kwazulu/Natal Subtropical Temporarily closed Poor Mdloti NN 3 Kwazulu/Natal Subtropical Temporarily closed Moderate Mdumbi TS 46 Transkei Subtropical Permanently open Nil Removal of mangroves and crop production Mendu TS 23 Transkei Warm temperate Temporarily closed Nil None - found within Dwesa Nature Reserve Mfazazana NS 29 Kwazulu/Natal Subtropical Temporarily closed Poor Mfolozi NN 18 KwazululNatal Subtropical River mouth Poor Mgeni NN I Kwazulu/Natal Subtropical Temporarily closed Good Mgobezeleni NN 20 Kwazulu/Natal Subtropical Estuarine lake Moderate Mgwalana CSE 19 Ciskei Warm temperate Temporarily closed Nil Bridges, grazing and bait digging Mgwegwe TN 31 Transkei Subtropical Temporarily closed Nil None, found within the Mkambati Nature Reserve Mgwetyana TN 32 Transkei Subtropical Temporarily closed Nil None, found within the Mkambati Nature Reserve Mhlabatshane NS 27 Kwazulu/Natal Subtropical Temporarily closed Poor Mhlali NN 5 Kwazulu/Natal Subtropical Temporarily closed Poor Mhlambankulu NS 22 KwazululNatal Subtropical Temporarily closed Poor Mhlanga NN 2 Kwazulu/Natal Subtropical Temporarily closed Good Mhlangeni NS 15 Kwazulu/Natal Subtropical Temporarily closed Poor Mhlathuze NN 16A Kwazulu/Natal Subtropical Permanently open Moderate Mhlungwa NS 28 Kwazulu/Natal Subtropical Temporarily closed Moderate Mkomazi NS 43 Kwazulu/Natal Subtropical Permanently open Moderate Mkozi TN 15 Transkei Subtropical Temporarily closed Nil Grazing within reed areas Mkumbane NS 37 Kwazulu/Natal Subtropical Temporarily closed Poor Mkweni TN 22 Transkei Subtropical Temporarily closed Nil None Mlalazi NN 15 Kwazulu/Natal Subtropical Permanently open Moderate Miele CSE 33 Eastern Cape Warm temperate Temporarily closed Nil Mnamfu NS 31 Kwazulu/Natai Subtropical Temporarily closed Poor Mncwasa TS 37 Transkei Subtropical Temporarily closed Nil Crop production in larger islands Mnenu TS 51 Transkei Subtropical Temporarily closed Nil None found within Dwesa Nature Reserve Mngazana TS 56 Transkei Subtropical Permanently open Good Mangrove removal, boating, boat houses, slipways, jetties and bait digging Mngazi TS57 Transkei Subtropical Temporarily closed Poor Slipways, jetties, boating and bait digging Mntafufu TN 6 Transkei Subtropical Permanently open Moderate Mangrove removal, terracing of floodplain for crop production Mnyameni TN 37 Transkei Subtropical Permanently open Nil Baiting digging, crop production and possible reed removalLoss of mangroves. Morgan CSE 57 Eastern Cape Warm temperate Temporarily closed Nil Mpahlane TN 39 Transkei Subtropical Temporarily closed Nil None Mpahlanyana TN 38 Transkei Subtropical Temporarily closed Nil None Mpako TS 40 Transkei Subtropical Temporarily closed Nil Grazing in floodplain resulting in erosion Mpambanyoni NS 40 Kwazulu/Natal Subtropical Temporarily closed Poor Mpande TS 53 Transkei Subtropical Temporarily closed Nil Mpekweni CSE 17 Ciskei Warm temperate Temporarily closed Nil Bridges, bait digging and boating Mpenjati NS 7 Kwazulu/Natal Subtropical Temporarily closed Poor Msikaba TN 27 Transkei Subtropical Permanently open Moderate None, found between the Msikaba and Mkambati Nature reserves. An increase in swamp forest observed. Msimbazi NS 46 Kwazulu/Natal Subtropical Temporarily closed Moderate Mtakatye TS 49 Transkei Subtropical Permanently open Nil Removal of mangroves, bait digging and housing. Mtambane TS 62 Transkei Subtropical Temporarily closed Poor Roads cuaseway and litter. Mtamvuna NS 1 Kwazulu/Natal Subtropical Temporarily closed Poor Mtana CSE 25 Ciskei Warm temperate Temporarily closed Nil Grazing and terracing of floodplain. The fallow fields have been invaded by A. karroo Mtata TS 45 Transkei Subtropical Permanently open Moderate Severe erosion in catchment, harvesting of mangroves and bait digging. Mtati CSE 18 Ciskei Warm temperate Temporarily closed Poor Bridges, grazing and boating Mtendwe CSE 55 Eastern Cape Warm temperate Temporarily closed Nil Mtentu TN 33 Transkei Subtropical Permanently open Poor High suspended sediment loads in water oolumn during flood periods Mtentwana TN 41 Transkei Subtropical Temporarily closed Poor Dam constructed at the head of estuary, boating and landfillin catchment. Mtentweni NS 21 Kwazulu/Natal Subtropical Temporarily closed Moderate Mtolane TN 36 Transkei Subtropical Temporarily closed Nil None Mtonga TS 52 Transkei Subtropical Temporarily closed Nil Grazing and bait digging Mtumbane TS 62 Transkei Subtropical Temporarily closed Nil Causeway, grazing Mtwalume NS 32 Kwazulu/Natal Subtropical Temporarily closed Moderate Mvoti NN 7 Kwazulu/Natal Subtropical River mouth Poor Mvubukazi CSE 39 Eastern Cape Warm temperate Temporarily closed Nil Mvutshini NS 11 Kwazulu/Natal Subtropical Temporarily closed Poor Mvuzi NS 33 Kwazulu/Natal Subtropical Temporarily closed Poor Myekane TN 16 Transkei Subtropical Temporarily closed Nil None Mzarnba TN 40 Transkei Subtropical Permanently open Moderate Grazing and access roads for the Wild Coast Casino complex (Set for a number of upcoming movies) Mzimayi NS 39 Kwazulu/Natal Subtropical Temporarily closed Poor Mzimkulu NS 20 Kwazulu/Natal Subtropical Permanently open Moderate Mzimpunzi TN 12 Transkei Subtropical Temporarily closed Nil Crop production on small floodplain acoompanied by reed removal Mzimvubu TS 63 Transkei Subtropical River mouth Nil Erosion in upper catchment, bridges and slipways Mzintlava TN 10 Transkei Subtropical Permanently open Nil None Mzinto NS 36 Kwazulu/Natal Subtropical Temporarily closed Poor Mzumbe NS 26 Kwazulu/Natal Subtropical Temporarily closed Moderate Nahoon CSE 44 Eastern Cape Warm temperate Permanently open Moderate Ncera CSE 32 Eastern Cape Warm temperate Temporarily closed Nil Ncizele TS 4 Transkei Warm temperate Temporarily closed Nil East bank is used for access to beach (4x4, 4x4 motorcycles) Nenga TS 43 Transkei Subtropical Temporarily closed Nil Causeway, agriculture and rubble Ngadla TS 26 Transkeí Warm temperate Temporarily closed Nil Grazing, crop production and bait digging Ngane NS 44 Kwazulu/Natal Subtropical Temporarily closed Poor Ngculura CSE 22 Ciskei Warm temperate Temporarily closed Nil Weir used for farmland abstraction, grazing and erosion in upper catchment. Ngogwane TS 2 Transkei Warm temperate Temporarily closed Nil Refuse tip for local holiday residents Ngoma TS 22 Transkei Warm temperate Temporarily closed Nil Grazing and reed harvesting Ngqenga CSE 40 Eastern Cape Warm temperate Temporarily closed Nil Ngqinisa CSE 25 Ciskei Warm temperate Temporarily closed Nil None Ngqusí\lnxaxo TS 8 Transkei Warm temperate Temporarily closed Crop production, grazing Ngqwara TS 11 Transkei Warm temperate Temporarily closed Nil Grazing and bait digging Nhlabane NN 17 Kwazulu/Natal Subtropical Estuarine lake Poor Nlcanya TS 31 Transkei Subtropical Temporarily closed Nil Grazing, housing, sand winning andbait digging Nkodusweni TN 4 Transkei Subtropical Temporarily closed Nil None Noetsie CMS 14 Western Cape Warm temperate Temporarily closed Poor Nonoti NN 9 Kwazulu/Natal Subtropical Temporarily closed Poor Nqabara TS 20 Transkei Warm temperate Permanently open Poor Reed and mangrove harvesting Ntlonyane TS 30 Transkei Subtropical Temporarily closed Nil Grazing and reed harvesting Ntlupeni TN 2 Transkei Subtropical Temporarily closed Nil Grazing, with an increase in ooastal forest cover. Nyara CSE 53 Eastern Cape Warm temperate Temporarily closed Nil Old woman's CSE 16 Ciskei Warm temperate Temporarily closed Nil Walkway, treated sewage and bait digging Olifants CW 10 Western Cape Cool temperate Permanently open Moderate Onrus CSW 14 Western Cape Warm temperate Temporarily closed Moderate Orange CW I Western Cape Cool temperate River mouth Good Palmiet CSW 12 Western Cape Warm temperate Permanently open Good Papkuils CSE 2 Eastern Cape Warm temperate Canalised Poor Piesang CMS 18 Western Cape Warm temperate Temporarily closed Moderate Qinira CSE 45 Eastern Cape Warm temperate Temporarily closed Poor Qolora TS 3 Transkei Warm temperate Temporarily closed Nil Boating, skiing and fishing Qora TS 14 Transkei Warm temperate Permanently open Nil Slipways, bait digging Quko CSE 56 Eastern Cape Warm temperate Temporarily closed Poor Ratel CSW 18 Western Cape Warm temperate Temporarily closed Poor Riet CSE 12 Western Cape Warm temperate Temporarily closed Nil Rietvlei/Diep CW 24/25 Western Cape Cool temperate Temporarily closed Good Rooiels CSW 10 Western Cape Warm temperate Temporarily closed Moderate Rufane CSE 11 Eastern Cape Warm temperate Temporarily closed Nil Sand CSW 4 Western Cape Warm temperate Temporarily closed Good Sandlundlu NS 3 Kwazulu/Natal Subtropical Temporarily closed Poor Schuster CW 30 Western Cape Cool temperate Temporarily closed Poor Seekoe CSW 5 Western Cape Warm temperate Temporarily closed Moderate Seekoei CMS 46 Eastern Cape Warm temperate Temporarily closed Good Seteni NN 6 Kwazulu/Natal Subtropical Temporarily closed Poor Sezela NS 36 Kwazulu/Natal Subtropical Temporarily closed Moderate Shixini IS 17 Transkei Warm temperate Permanently open Poor Bait digging, grazing and erosion of estuary banks Shwele-Shwele CSE 27 Ciskei Warm temperate Temporarily closed Nil None Sihiontlweni TS 12 Transkei Warm temperate Temporarily closed Nil Grazing and reed harvesting Sikombe TN 34 Transkei Subtropical Temporarily closed Nil Grazing on floodplain Silvermine CSW 3 Western Cape Warm temperate Temporarily closed Moderate Sinangwana TS 54 Transkei Subtropical Temporarily closed Nil Grazing, crop production and reed harvesting Sipingo NS 51 Kwazulu/Natal Subtropical Modified permanently oper Moderate Sir Lowrys Pass CSW 8 Western Cape Warm temperate Temporarily closed Moderate Siyaya NN 14 Kwazulu/Natal Subtropical Temporarily closed Poor Sout Oos CMS 22 Western Cape Warm temperate Permanently open Moderate Sout Wes CW 26 Western Cape Cool temperate Temporarily closed Poor Spoeg Western Cape Cool temperate Temporarily closed Nil None St Lucia NN 19 Kwazulu/Natal Subtropical Estuarine lake Excellent Steenbras CSW 9 Western Cape Warm temperate Permanently open Moderate Storms CMS 32 Eastern Cape Warm temperate River mouth Nil Sundays CSE 5 Eastern Cape Warm temperate Permanently open Excellent Sundwana TS 32 Transkei Warm temperate Temporarily closed Swartkops CSE 3 Eastern Cape Warm temperate Permanently open Excellent Swartvlei CMS 11 Western Cape Warm temperate Estuarine lake Excellent Tongati NN 4 Kwazulu/Natal Subtropical Temporarily closed Moderate Tongazi NS 5 KwazululNatal Subtropical Temporarily closed Poor Tshani None Transkei Subtropical Temporarily closed Nil None Tsitsikamma CMS 42 Eastern Cape Warm temperate Temporarily closed Poor Tugela NN 11 Kwazulu/Natal Subtropical River mouth Poor Tyolomnqa CSE 30 Ciskei Warm temperate Temporarily closed Nil Boating and bait digging Uilkraals CSW 17 Western Cape Warm temperate Temporarily closed Moderate Umgababa NS 45 Kwazulu/Natat Subtropical Temporarily closed Moderate Umhlangankulu NS 8 Kwazulu/Natat Subtropical Temporarily closed Moderate Uvuzana NS 12 Kwazulu/Natat Subtropical Temporarily closed Poor Van Stadens CMS 49 Eastern Cape Warm temperate Temporarily closed Nil Verlorenvlei CW 13 Western Cape Cool temperate Temporarily closed Moderate Vungu NS 14 Kwazulu/Natal Subtropical Temporarily closed Moderate Wilderness CMS 10 Western Cape Warm temperate Estuarine lake Excellent Wildevoèlvlei CW 28 Western Cape Cool temperate Temporarily closed Poor Xora 15 33 Transkei Subtropical Permanently open Nil Mangrove removal, boating, boat houses, jetties, slipways and bait digging Zalu None Transkei Warm temperate Temporarily closed Nil Grazing and reed harvesting Zinkwazi NN 10 Kwazulu/Natal Subtropical Temporarily closed Poor Zolwane NS 2 Kwazulu/Natal Subtropical Temporarily closed Poor Zotsha NS 17 Kwazulu/Natal Subtropical Temporarily closed Moderate AppendixEstuary Table - Availability of information for the different estuaries YesBotanical survey YesNitrate YesPhytoplankton Chi-a YesBenthic Chi-a YesPhytoplankton counts N/AMangrove transects GqunqeCebeBulungulaBululoBita Yes YesYesNo YesNo YesNo YesNoNo N/ANIA GweGwaraGreatGgutywa Gwe Kei Yes YesYes Yes Yes Yes N/A JujuraKiwaneKeiskammaHiuleka Yes YesNo YesNo YesNo YesNo N/A LupatanaKwanyanaKu-amanzimuzamaKobonqaba Yes YesNoNo YesNo NoYesYesNo YesNoNo YesN/A MbasheMapuziLwandileLwandilana Yes YesNo NoYes NoYes YesNoYes YesN/A MgwalanaMenduMdumbiMbotyi Yes YesYes Yes Yes YesYes N/AYes MnenuMncwasaMkweniMkozi Yes Yes Yes Yes Yes N/A MpahlaneMnyameniMntafufuMngazi Yes NoYes YesNo NoYes NoYes N/AYes MsikabaMpekweniMpakoMpahlanyana Yes YesNo YesNo YesNo YesNo N/A MtataMtanaMtambaneMtakatye Yes YesNo YesNo YesNo YesNo YesN/A MtongaMtentwanaMtentuMtati Yes NoYes NoYes NoYes NoYes N/AYes MzimvubuMzimpunziMzambaMyekane Yes YesNo YesNo YesNo YesNo YesN/A NgculuraNengaNcizeleMzintlava Yes Yes YesNo YesNo YesNo N/AYesN/A NkanyaNgqwaraNgomaNgogwane Yes NoYes YesNo NoYes YesNo N/A NtlupeniNtlonyaneNqabaraNkodusweni NoYes No NoNo NoNo NoNo N/AYesN/A QoloraOldNxaxo womans YesNo Yes YesNo YesNo YesNo YesN/ANIA SikombeSihlontiwentShwele-ShweleShixiniQora YesNo YesNo YesYesNo YesNo YesNo N/A XoraUmganzanaTyolomnciaSinangwana Yes Yes Yes Yes Yes YesN/A Appendix Table -Past area (ha) covered by the different plant community types Estuary Intertidal salt marsh Supratidal salt marsh Submerged macrophytes Reeds and sedges Mangroves Benthic microalgae Phytoplankton Macroalgae Swamp forest Berg (Groot) Bilanhiolo Bira 0 5.3 2.2 23.3 o 18.41 122.45 o o Blind Blinde Bloukrans Blue Krans 0 0 0 1.58 o 0.12 0.58 0.26 o Boboyl Boknes Bokramspruit Bot/Kleinmond 0 92.4 0 113.5 0 152.3 1340.2 O O Bree Buffalo Buffets 0 37.5 0 152 0 50 0.5 0 0 Buffets Oos 0 1.78 0 0.47 0 0.45 12.26 0 0 Buffets Wes O 0 0 0.48 0 1.67 1.58 0.02 0 Bululo 0 0 0 4.5 0 0.02 6.3 0 0 Bulungulu 0 2.8 0 4.65 - 3.5 6 8.9 0 0 Bulura Bushmans Butsha O 0 0 0.35 0 0 0.8 0 2.9 Cebe O 0 0 7.89 0 1.4 7.5 0 o Cefane Cintsa Cunge Cwili Damba Duiwenhoks 50.78 0 0 0 0 19.38 72.91 0 0 Durban Bay Eerste Elands Elandsbos Elsies O 0 0 3.76 0 1.13 1.52 0 0 Fafa Freshwater Poort O 0 0 0.5 0 0.1 0.15 0.15 0 Gamtoos 112.46 245.07 0 33.39 0 34.89 274.78 0 0 Goda Goukamma Goukou 44.2 0 0 0 0 62.78 47.78 0 0 Gourits 21.07 0 0 0 0 28.75 91.51 0 0 Gqunqe O 0 0 9.2 0 0.89 7.85 0 0 Gqunube Gqutywa 0 1.85 1.96 2.02 0 4.47' 38.1 1.56 0 Gqwara 0 5.4 0 7.56 0 0.05 10.1 2.3 0 Great Fish 47.3 154.2 0 16.6 0 4.54 139.5 0 0 Great Kel 4.2 7.8 0 11.2 0 6.7 189.4 0 0 Groen 0 8.15 5.63 5.23 0 5.64 12.45 2.35 0 Groot Brak Groot Oos Groot Wes Gwaing Gxara 0 1.89 0 6.31 0 1.5 14.2 0 0 Gxulu Gxwaleni O 0 0 5.6 0 0.02 4.5 0 0 Haga-haga Hartenbos 2.04 13.62 1.2 0 0 9.21 15.72 0.2 0 Heuningnes 0 26.15 0 3.13 0 101.86 39.37 0 0 Hickmans Hlaze Hiozi Hiuleka O 0 0 1.45 0 4.1 8.96 0 0 Hout Bay O 0 0 17.15 0 2.53 1.37 0 0 lntshambili Jujura 0 0 0.01 1.2 0 0.07 3.45 0 0 Kaaimans Kaba Kabeljous 0 8.29 1.68 0.87 0 0 49.36 0 0 Kandandhlovu Kariega Kasuka Keiskamma 210.37 311.78 12.03 103.07 0 49.18 277.8 0 0 Keurbooms 42.9 0 64.05 5.78 0 5442 192.07 1.03 0 Kiwane 0 0 3.56 7.25 0 15 8.95 1.57 0 Klein 156 45 37 15.2 0 452.1 2250 3.6 0 Klein Brak Kleinemond Oos Kleinemond Wes Klipdrif Klipdrifsfontein Knysna 405.8 389.2 348.2 105.26 0 1000 1633 0 0 Kobonqaba 2.3 4.5 0 2.4 3.5 4.6 11.2 0 0 Koega Kongweni Koshwana Kosi Kowie Krom Oos 17.64 74.01 2.35 0 0 52.58 116.62 0 0 Krom Wes Ku-amanzimuzama O 0 0 1.2 0 1.05 1.4 0 0 Ku-Shula O 0 0 2.7 0 0 2.6 2.3 0 Ku-boboyi Ku-Mpenzu O 0 0 4.3 0 1.24 6.54 1.3 0 Kwa-Makosi Kwa-Nyambalala O 0 0 0.02 0 0.01 0.57 0 0 Kwanyana O 0 O 0.45 0 0.1 6.32 0 0 Kwa-Suka 0 0 2.3 7.6 0 0.01 8.23 0 0 Kwelera Kwenxura Langebaan Lilyvale Little Manzimtoti Lottering Lourens Lovu Lupatana O 0 0 0.22 0 0.15 2.73 0 0.42 Lwandilana O O 0 2.4 0 0.08 7.21 0 0 Lwandile O O 0 7.4 0 2.4 12.4 0 0 Maalgate Mahlongwa Mahlongwana Maitland Manzimtoti Mapuzi O O O 7.45 0 0 8.45 0 0 Matigulu/Nyoni Matjies Mbango Mbashe 2.8 0 0.9 12.56 12.5 6.7 89.2 0 4.8 Mbhanyana 0 0 0 6.3 0 1.4 6.98 1.2 0 Mbizana Mbokodweni Mbotyi 0 0 0 4.16 0 11.41 32.32 0 1.25 Mcantsi Mdesingwana Mdlotane 0 0 0.66 9.97 0 0 5.93 O 1.92 Mdloti O 0 0 10 0 7.3 33 7.8 0 Mdumbi 0 17.1 0 7.9 1 13.88 45.57 0 0 Mendu O 0 0 9.51 0 0 14.32 0 0 Mfazazana Mfolozi Mgeni Mgobezeieni Mgwalana 0 8.53 5.65 36.14 0 5.34 154.3 9.56 0 Mgwegwe O 0 0 0.15 0 0.8 3.39 0 0.45 Mgwetyana O 0 0 0.27 0 0.56 2.45 0 0 Mhiabatshane Mhlali Mhlambankulu O O O 0 0 0.68 0.94 0 0 Mhlanga O 0 0 69.9 0 0 30 0 0.2 Mhlangeni Mhlathuze 50 0 63 590 150 110 2000 0 29 Mhlungwa Mkomazi O 0 0 8 9 4.9 62.8 0 0 Mkozi O 0 0 0.5 1.29 0.12 2.1 0 0 Mkumbane Mkweni O 0 0 0.34 0 0.15 5.19 0 1.32 Mlalazi 0 204.47 4.3 19.92 0 19.8 95.86 0 0.94 Miele Mnamfu Mncwasa O 0 0 7.7 0 0.156 15.36 0 0 Mnenu O O 0 51.44 0 0.08 46.46 0 0 Magazana 1.5 8.9 2.3 8.9 150 2.3 45.6 0 7.3 Magazi O 0 0 5.7 0 2.3 12.5 0 0 Mntafufu O 0 0 5.4 15.05 0.75 7.65 0 1.09 Mnyameni O 0 0 8.46 3 2.34 17.11 0 0.01 Morgan Mpahlane O 0 0 0.66 0 0.29 2.97 0 0 Mpahlanyana O 0 0 0.74 0 0.1 3.01 0 0 Mpako O 0 0 6.68 0 0.96 7.42 0 0

Mpambanyoni - Mpande O 0 0 6.7 0 0.5 7.84 0 0 Mpekweni 0 8.59 1.12 19.2 0 15.24 63.39 0 0 Mpenjati Msikaba O O 0 0.49 0 2.81 10.94 0 0 Msimbazi Mtakatye 0 13.94 3.56 3.72 9 5.21 75.6 0 0 Mtambane O O 0 4.51 0 0.12 4.12 0 0 Mtamvuna Mtana 0 2.75 2.5 1.25 0 0.75 7.1 0 0 Mtata 0 26.86 0.15 9.45 34 5.62 102.41 0 0 180.15 0 0 Mtati O 69.3 5.2 26.2 0 1.45 Mtendwe 1 0 3.67 Mtentu O o o 2.76 8.08 34.95 0 0 Mtentwana O o o 1.76 0 1.22 10.21 Mtentweni 0.14 1.15 0 0 Mtolane O O O 0 0 1.2 15.4 0 0 Mtonga O o 0 15.6 0 0 0 Mtumbane O o 0 4.56 0 1.2 9.56 Mtwalume Mvoti Mvubukazi Mvutshini Mvuzi 0 0 Myekane O o 0 0.3 0 0.49 1.13 0 4.74 Mzamba O o 0 24.11 1 3.97 37.87 Mzimayi Mzimkulu 3.07 0 0 Mzimpunzi O o 0 1.41 0 0.6 102.23 0 11.23 Mzimvubu O o 0 24.3 1 15.23 14.42 0 0.35 Mzintlava O o 0 3.09 2.31 2.89 Mzinto Mzumbe Nahoon Ncera 5.4 0 0 Ncizele O o 0 1.23 0 0.005 5.74 0 0 Nenga O o 0 5.01 0 2.17 8.65 0 0 Ngadla O O 0 5.23 0 0.004 Ngane 1.15 0.5 0 0 Ngculura O o 0 0.35 0 2.1 4.67 0 0 Ngogwane O o 0 2.35 0 4.56 1.23 0 0 Ngoma O o 0 4.32 0 Ngqenga 9.05 0.56 0 Ngqinisa O O 0 1.34 0 0.15 Ngqusi\lnxaxo 2.67 12.56 1.2 3.56 14 4.56 124.32 0 0 0 2.1 10.24 0 0 Ngqwara O 2.34 0 4.68 0 5.7 0 0.3 Nhlabane O 0 0.6 9.3 0 7.52 0.5 0 Nkanya O o 0 7.4 0 0.05 5.5 22.4 0 0 Nkodusweni O o 0 4.7 0 Noetsie Nonoti 89.54 0 1.23 Nqabara O 0 1.2 4.56 9 4.63 0 0 Ntlonyane O o 0 17.18 0 3.89 29.46 0.14 4.1 0 0 Ntlupeni O o 0 0.13 0 Nyara 0.1 10.7 0.15 0 Old woman's O o 0 19.27 0 Olifants Onrus 652.5 0 0 Orange 289.8 136.79 0 73.4 0 108.3 11 21.4 0 0 Palmiet 0.1 O O O 0 Papkuils Piesang Qinira 0 1.5 7.9 4.1 0 Qolora O O 0 9.5 0 10.23 65.23 0 0 Qora O o 7.56 5.67 Quko Ratel 0 36.2 1.52 0 Riet O 17.4 2.64 12.3 3 Rietvlei/Diep Rooiels 0.13 0.2 0.03 1.81 0 8.3 1.8 0.01 0 Rufane Sand Sandlundlu Schuster Seekoe 0 0 0.2 0.66 0 1.48 0.78 0.05 0 Seekoei 0 11.05 0 12.92 0 7.49 63.52 0 0 Seteni Sezela Shixini O 0 0 5.64 0 5.23 11.23 0 0 Shwele-Shwele O 0 0 1.34 0 0.41 5.65 0.56 0 Sihiontlweni O 0 0 2.56 0 0.05 8.4 0 0 Sikombe O 0 0 0.3 0 0.79 9.21 0 1.18 Silvermine O 0 0 2.02 0 1.65 0.09 0 0 Sinangwana O 0 0 8.9 0 0 5.8 0 0 Sipingo Sir Lowrys Pass O 0 0 0.04 0 1.74 1.17 0 0 Siyaya 0 0 0.36 0.27 0 0 3.19 0 0.24 Sout Oos Sout Wes Spoeg StLucia 632 1270 181 6032 169 206 31610 0 0 Steenbras O O O 0 0 0.32 1.88 0 0 Storms Sundays Sundwana O 0 0 2.3 0 0.01 4.32 0 0 Swartkops 215 40 16 10 0 177 135 0 0 Swartvlei 53.03 0 22.89 114.03 0 133.36 630.91 122.41 0 Tongati O 0 0 17.2 0 2.8 13.9 0 3.4 Tongazi Tshani 0 0 0 1.23 0 0.004 2.78 0 0 Tsitsikamma Tugela Tyolomnqa 10.48 30.15 0 0.25 0 0.07 87.71 0 0 Uilkraals 0 37.7 1.4 5.6 0 46 21 0.5 0 Umgababa Umhlangankulu Uvuzana Van Stadens Verlorenvlei 16.2 7.56 3.68 2.3 0 0 4.5 0.5 0 Vungu Wilderness Wildevoêlvlei 12.72 0 0.05 15.38 0 172.31 30.46 1.2 0 Xora 0 15.65 0.56 21.18 16 17.13 91.45 0 0 Zalu O O 0 5.2 0 0.02 7.14 0 0 Zinkwazi O O 0 44.47 0 0 23.63 0 3.53 Zoiwane Zotsha Appendix Table - Recent area (ha) covered by the different plant community types Estuary Intertidal salt marsh Suprtidal salt marsh Submerged macrophytes Reeds and sedges Mangroves Benthic microalgae Phytoplankton Macroalgae Swamp forest Berg (Groot) 141.8 1 536.1 322.7 898.9 o 193.5 522 0 0 Bilanhlolo Bira 0 2.59 5.3 15.16 o 18.04 122.45 O O Blind 0 0.1 0 0 o 0 0.4 o O Blinde Bloukrans Blue Krans O 0 0 1.58 0 0.12 0.58 0.26 0 Boboyi Boknes Bokramspruit Bot/Kleinmond Breé 41.08 0 0 0 0 43.46 370.74 0 0 Buffalo 0 0.1 0 0.2 0 0 97.7 0 0 Buffels Buffels Oos 0 1.48 0 3.37 0 0.05 12.38 0 0 Buffels Wes Bululo O 0 0 6.3 0 0.02 6.3 0 0 Bulungulu 0 2.3 0 4.7 0 2.5 8.9 0 0 Bulura 2.8 5.6 0.4 2.7 0 4.6 19.4 0 0 Bushmans O Butsha O 0 0 0.35 0 0 0.8 0 1.74 0 Cebe O 0 0 7.63 0 1.4 7.5 0 Cefane 28.1 21.4 0 1.9 0 8.8 22.5 0 0 Cintsa 7 7.1 0 1 0 1.6 12.6 0 0 Cunge O 0 0 0.2 0 0 0.3 0 0 Cwili O 0 0 0.6 0 0 0.6 0 0 Damba O Duiwenhoks 50.78 0 0 0 0 79.38 72.91 0 0 Durban Bay O Eerste 0.29 0 0 1.36 0 6.15 2.4 0 0 Elands O Elandsbos O Elsies O 0 0 3.76 0 1.67 13.02 0 0 Falo O Freshwater Poort O 0 0 0.5 0 0.1 0.15 0.15 0 Gamtoos 40.45 163.23 0 36.02 0 71.13 215.35 0 0 Goda 0 1.9 0 1.1 0 0.6 13.6 0 0 Goukamma O Goukou 44.2 0 0 0 0 62.78 47.78 0 0 Gourits 21.07 0 0 0 0 0 91.51 0 0 Gqunqe O 0 0 9.2 0 0.89 7.85 0 0 Gqunube 3.7 2.2 0.8 0.4 0 6.3 40 0 0 Gqutywa 0 1.23 2.5 3.78 0 4.47 38.1 1.56 0 Gqwara 0 5.4 0 7.56 0 0.05 10.1 2.3 0 Great Fish 46.7 152.3 0 16.6 0 10.58 139.5 0 0 Great Kei 5.8 6.2 0 12.3 0 8.7 189.4 0 0 Groen 6.03 27.34 10.56 0 0 Groot Brak 5.36 34.83 0 4.34 0 30.93 38.46 0 0 GrootOos O GrootWes 0 0.76 0 2.54 0 8.12 27.86 0 0 Gwaing O Gxara 0 1.89 0 6.31 0 1.5 14.2 0 0 0 Gxulu 1 11.9 0 0.6 0 4 31 0 0 Gxwaleni O 0 0 5.6 0 0.02 4.5 0 Haga-haga 0 0.3 0 0.4 0 1.4 1.3 0 0 Hartenbos 2.04 13.62 0 0 0 9.21 15.72 0 0 Heuningnes 28.15 0 0 3.13 0 101.86 39.37 0 0 Hickmans 0 0.8 0 0.4 0 0 3.1 0 0 Hiaze 0 0.1 0 0.7 0 0 0.7 0 0 Hiozi O 0 0 0.3 0 0 0.4 0 0 Hluleka O 0 0 2.35 0 4.1 8.45 0 0 Hout Bay O lntshambili O Jujura 0 0 0.05 1.2 0 0.07 3.45 0 0 Kaaimans O Kaba O Kabeljous 0 10.45 21.51 8.56 0 0 77.42 0 0 Kandandhlovu

Kariega O

Kasuka O Keiskamma 210.37 91.26 11.33 103.9 0 49.18 277.82 0 0 Keurbooms 42.9 0 0 5.78 0 54.42 192.07 0 0 Kiwane 0 0 3.56 4.56 0 0.15 8.96 1.57 0 Klein O Klein Brak O Kleinemond Oos O Kleinemond Wes O Klipdrif O Klipdrifsfontein O Knysna 464 60 355 82 0 1 000 1 633 0 0 Kobonqaba 2.3 4.5 0 2.4 1.5 4.6 11.1 0 0 Koega 0 2.3 1.2 4.3 0 0.04 2.3 0 0 Kongweni O Koshwana O Kosi O Kowie 35.2 0 0 6.36 0 33.99 43.08 0 0 KromOos 18.13 67.17 11.98 3.07 0 37.03 102.96 0 0 Krom Wes O Ku-amanzimuzama O 0 0 1.2 0 1.05 1.4 0 0 Ku-Bhula O 0 0 2.7 0 0 2.6 2.3 0 Ku-boboyi O Ku-Mpenzu O 0 0 4.3 0 1.24 6.54 1.3 0 Kwa-Makosi O Kwa-Nyambalala O 0 0 0.02 0 0.01 0.57 0 0 Kwanyana O 0 0 0.71 0 0.1 6.32 0 0 Kwa-Suka 0 0 2.3 7.6 0 0.01 8.23 0 0 Kwelera 9.3 7.2 2.3 0.3 0 4.4 26.6 0 0 Kwenxura 0 3.3 0 2.6 0 5 18.2 0 0 Langebaan 123.3 250.61 0 0 0 10.2 450.6 0 0 Lilyvale O 0 0 0.5 0 0 1.8 0 0 Little Manzimtoti O Lottering O Lourens O 0 0 0.58 0 4.01 2.5 0 0 Lovu O Lupatana O O 0 0.22 0 0.15 2.73 0 0.45 Lwandilana O O 0 2.4 0 0.08 7.21 0 0 Lwandile O O 0 7.4 0 2.4 12.4 0 0 Maalgate O Mahlongwa O Mahlongwana O Maitiand O Manzimtoti O Mapuzi 0 0 0 7.45 0 0 8.45 0 0 MatigululNyoni O Matjies O Mbango O Mbashe 2.3 0 1.5 13.45 14 6.7 89.2 0 4.8 Mbhanyana 0 0 0 6.3 0 1.4 6.98 1.2 0 Mbizana O Mbokodweni O Mbotyi O O 0 4.16 0 11.41 32.32 0 2.5 Mcantsi 0 0.5 0 4 0 0.5 4 0 0 Mdesingwana O Mdiotane 0 0 0.71 6.03 0 0 6.35 0 12.33 Mdioti O O O io o 7.3 33 0 7.8 Mdumbi 0 8.17 0.05 7.9 0.5 13.88 45.57 0 0 Mendu O O 0 9.51 0 0 14.32 0 0 Mfazazana O Mfolozi O Mgeni O Mgobezeieni O Mgwaiana 0 7.62 1.12 48.78 0 5.34 154.3 9.56 0 Mgwegwe O 0 0 0.15 0 0.8 3.39 0 4.45 Mgwetyana O 0 0 0.27 0 0.56 2.45 0 0 Mhiabatshane O Mhiaii O Mhiambankuiu Mhianga O 0 0 69.9 0 0 30 0 0.2 Mhiangeni Mhiathuze 60 0 5 205 652 90 679 0 0 Mhiungwa Mkomazi O 0 0 5 5.2 4.9 62.8 0 0 Mkozi O 0 0 0.5 1.29 0.12 2.1 0 0 Mkumbane Mkweni O O 0 0.34 0 0.15 5.19 0 1.32 Mlalazi 0 39.31 0.001 19.64 24.37 19.8 95.86 0 3.46 Miele 0 0.4 0 0.5 0 0 2.7 0 0 Mnamfu Mncwasa O 0 0 3.7 0 0.156 15.36 0 0 Mnenu O 0 0 44 0 0.08 46.44 0 0 Mngazana 1.25 7.4 0.8 11.4 145 5.6 45.6 0 7.8 Mngazi O 0 0 4.6 0 0 12.5 0 0 Mntafufu O 0 0 1.5 13.7 0.75 7.65 0 0.47 Mnyameni O 0 0 8.46 0 2.34 17.11 0 0.01 Morgan 0 2 0 1 0 1 20 0 0 Mpahiane O 0 0 0.66 0 0.29 2.97 0 0 Mpahianyana O 0 0 0.74 0 0.1 3.01 0 0 Mpako O 0 0 5.13 0 0.96 7.42 0 0 Mpambanyoni Mpande O O 0 6.7 0 0.5 7.84 0 0 Mpekweni 0 27.2 1.59 20.98 0 13.15 63.39 15.1 0 Mpenjati Msikaba O O 0 0.49 0 2.81 10.94 0 0.89 Msimbazi Mtakatye 0 18.19 1.25 7.56 9 5.21 75.6 0 0 Mtambane O O 0 5.41 0 0.12 5.41 0 0 Mtamvuna 0 0 0 15.23 0.25 2.36 45.69 0 0 Mtana 0 2.5 2.54 1.25 0 0.15 7.1 2.15 0 Mtata 0 21.03 0 6.23 33.5 5.62 102.41 0 0 Mtati 0 54.25 3.2 26.2 0 1.45 180.15 21.1 0 Mtendwe Mtentu O O 0 4.76 1.47 8.08 34.95 0 3.67 Mtentwana O O O 0 0 1.22 10.21 0 0 Mtentweni Mtolane O O O 0 0 0.14 1.15 0 0 Mtonga O 0 0 15.6 0 1.2 15.4 0 0 Mtumbane O 0 0 4.56 0 1.2 9.56 0 0 Mtwalume Mvoti Mvubukazi O O O O 0 0 0.1 0 0 Mvutshini Mvuzi Myekane O 0 0 0.3 0 0.49 1.13 0 0 Mzamba O 0 0 24.11 0.25 3.97 37.87 0 4.74 Mzimayi Mzimkulu Mzimpunzi O 0 0 1.41 0 0.6 3.07 0 0 Mzimvubu O 0 0 22.3 0 15.23 102.23 0 11.23 Mzintlava O 0 0 3.09 2.31 2.89 14.42 0 0.35 Mzinto Mzumbe Nahoon 2.8 0 2.3 0.2 0.6 4.5 47.3 0 0 Ncera 0 2.9 1 0.9 0 6.7 16.9 0 0 Ncizele O 0 0 1.23 0 0.005 5.4 0 0 Nenga O 0 0 2.1 0 2.17 5.74 0 0 Ngadla O 0 0 5.23 0 0.004 8.65 0 0 Ngane Ngculura O 0 0 0.7 0 1.15 0.5 0 0 Ngogwane O 0 0 2.35 0 2.1 4.67 0 0 Ngoma O 0 0 4.32 0 4.56 1.23 0 0 Ngqenga O O O O 0 0 0.1 0 0 Ngqinisa O 0 0 2.3 0 0.12 9.05 1.2 0 Ngqusi\lnxaxo 2.35 8.56 0.04 4.65 15 4.56 124.32 0 0 Ngqwara 0 2.34 0 4.68 0 2.1 10.24 0 0 Nhlabane 0 0 1.1 7.8 0 0 5.2 0 0.3 Nkanya O 0 0 7.4 0 0.05 7.52 0.5 0 Nkodusweni O 0 0 4.7 0 5.5 22.4 0 0 Noetsie Nonoti Nqabara 0 0 1.2 4.56 8.5 4.63 89.54 0 1.23 Ntlonyane O 0 0 7.99 0 3.89 29.46 0 0 Ntlupeni O 0 0 0.13 0 0.14 4.1 0 0 Nyara 1.1 6.3 0 0.6 0 1.7 7.4 0 0 Old womans O 0 0 14.17 0 0.1 10.7 0.15 0 Olifants 196.79 284.9 0 0 0 55.92 164.08 0 0 Onrus O O 0 41.08 0 0 0.05 0 0 Orange 83.9 107.8 0 22.02 0 108.3 652.5 0 0 Palmiet 0.1 0 0 0 0 11 21.4 0.5 0 Papkuils O O O O O O O O O Piesang O O 0 3.14 0 80.6 8.5 0 0 Qinira 16.83 5.7 0 15.2 0 0 34.4 0 0 Qolora O O 0 8.7 0 1.2 7.4 5.6 0 0 0 Qora O O 8.5 5.67 0 10.23 65.23 Quko 3.9 0 0 1.2 0 0.08 31 0 0 Ratel Riet Rietvlei/Diep Rooiels 0 0 0.03 1.81 0 8 I O O Rufane Sand 11.55 0 0 39.76 0 7.02 97.15 0 0 Sandlundlu Schuster Seekoe Seekoei 0 8.18 14.25 26.42 0 0 83.37 0 0 Seteni Sezela Shixini O 0 0 5.64 0 5.23 11.23 0 0 Shwele-Shwele O O 0 1.34 0 0.41 5.65 0.56 0 Sihlontlweni O 0 0 2.56 0 0.05 8.4 0 0 Sikombe O 0 0 0.3 0 0.79 9.21 0 1.18 Silvermine 0 0.19 2.02 2.21 0 2.01 0.09 0 0 0 Sinangwana O 0 0 7.4 0 0 5.8 0 Sipingo Sir Lowry's Pass 0.04 1.74 1.17 Siyaya 0 0 0.08 5.31 0 0.21 0.76 0 1.33 Sout Oos 0 0.49 0 0 0 9.3 42.43 0 0 Sout Wes Spoeg St Lucia 516 1 706 181 3789 279 206 31 610 0 3 0 0 Steenbras O O O O 0 0 1.88 Storms Sundays 1.56 2.56 4.56 15.23 0 4.23 145.23 0 0 Sundwana 0 0 0 2.3 0 0.01 4.32 0 0 Swartkops 165 5 12.5 4.5 0 177 135 0 0 Swartvlei 0 3.4 Tongati O O 0 17.2 0 2.8 13.9 Tongazi 0 0 Tshani O O 0 1.23 0 0.004 2.78 Tsitsikamma Tugela Tyolomnqa 3.7 15.67 0 0.29 0 0.07 87.71 0 0 Uilkraals O 0 37.7 0 0 46 21 0 0 Umgababa Umhlangankulu Uvuzana Van Stadens Verlorenvlei Vungu Wilderness 0 Wildevoêlvlei 12.72 O 0 15.38 0 172.31 30.46 0 Xora 0 12.96 2.6 10.12 16.32 17.13 91.45 0 0 0 0 Zalu O O 0 5.2 0 0.02 7.14 0 11.28 Zinkwazi O O 0 39.51 0 0 20.37 Zoiwane Zotsha AppendixEstuary Table - Water quaIit data for the different estuaries Average Minimum Salinity (g 11) Maximum Average ChlorophyllMinimum a (pg Maximum F1) Average MinimumNitrate (pM) Maximum CebeBulungulaBululoBira 23.37515.28 9.520.1 23.526.4 6.1412.06 3.29.2 7.515.2 26.5815.44 12.412.1 52.123.2 GwaraGreatGqutywaGqunqe Kel 17.3215.8616.3217.42 15.212.312.512.3 23.223.619.218.5 11.1413.4613.9612.98 6.57.211.29.5 14.326.415.6 26.8419.3224.0413.466 1225.121.111.2 25.128.332.116.4 KeiskammaJujuraHiulekaGwe Gwe 15.4614.92 12.512.311.2 38.918.518.9 17.5614.29.42 11.35.2 16.215.3 14.4214.44 15.11212.3 18.218.3 KwanyanaKu-amanzimuzamaKobonqabaKiwane 17.7615.3429.8 15.4.12.3 21.418.5 23.9212.06 22.19.515.4 26.515.621.2 23.4419.2213.5 15.611.1 21.415.632.3 MapuziLwandileLwandilana,Lupatana 6.49.4219.4816.46 4.55.312.214.2 12.115.626.518.9 14.4817.766.3211.9 12.112.35.310.1 23.215.67.813.5 19.713.7213.315.02 9.612.110.211.2 26.322.115.6 MenduMdumbiMbotyiMbashe 5.49.6610.26 7.52.34.5 14.27.912.3 23.1615.927.16 4.52114.2 26.118.412.3 26.1624.2422.38 23.621.512.1 29.226.826.2 MncwasaMkweniMkoziMgwalana 13.7812.4617.911.16 4.511.210.112.4 22.315.617.5 22.5816.5617.1214.38 2112.515.4 20.426.119.516.2 22.5614.4416.4426.24 21.312.314.225.1 24.115.928.318.2 MnyameniMntafufuMngaziMnenu 13.2611.9416.6616.92 2.56.514.512.3 20.521.316.3 25.162217.514.52 15.223.511.215.3 23.227.120.126.4 25.5225.115.123.94 23.521.512.322.1 26.729.216.5 MpekweniMpakoMpahlanyanaMpahlane 12.664.72 5.61.2 21.58.9 19.4618.14 15.613.4 25.622.1 25.6216.5 15.221.6 18.332.5 MtanaMtambaneMtakatyeMsikaba 13.026.2815.44 10.24.512.3 15.69.520.3 13.6615.316.86 11.215.4 15.117.218.7 23.2224.6624.04 22.122.321.2 26:225.326.3 MtentwanaMtentuMtatiMtata 18.113.3623.1414.48 11.212 25.315.63218.9 12.5613.2213.8813.74 5.611.212.312.1 15.215.4 25.1224.3219.2810.74 20.18.621.315.2 23.626.332.515.2 MzimpunziMzambaMyekaneMtonga 15.22 11.5 21.1 14.9 12.1 17.3 20.4 18.5 24.3 NengaNcizeleMzintlavaMzimvubu 15.6822.5613.14 12.311.212.3- 18.915.635.6 5.028.6416.82 2.55.615.6 7.110.118.4 12.6414.2220.621.62 9.211.615.615.2 26.229.516.318.2 NkanyaNgqwaraNgomaNgogwaneNgculura 14.6413.810.2615.76 12.311.25.614.3 18.415.614.517.4 9.815.1812.466.2 4.59.25.411.2 8.117.215.415.2 14.3216.0423.822.64 12.512.322.115.6 15.719.526.5 NtlupeniNtlonyaneNqabaraNkodusweni QoraQoloraOldNxaxo womans 13.5817.0215.28 12.114.512.3 15.619.218.4 15.1213.2815.02 12.211.2 18.915.618.4 16.9817.3619.06 14.216.215.2 19.519.225.6 SikombeSihlontlweniShwele-ShweleShixini 15.9614.1214.84 12.3 18.515.616.5 13.4415.0413.62 9.511.212.3 15.616.515.4 21.4216.5213.7 15.612.611.2 25.419.516.2 XoraUmganzanaTyolomnqaSinangwana 19.625.0618.0813.34 16.915.612.511.2 2335.621.216.4 15.4820.3613.3412.86 13.512.311.22.3 18.727.115.421 22.8429.0424.4823.68 21.221.521.619.5 25.427.926.436.5