Estuaries require sufficient quantity, quality and appropriate timing of freshwater inflow, referred to as environmental flow requirements, to ensure adequate health and functioning. In South Africa the environmental flow requirements of estuaries is determined using Resource Directed Measures (RDM). The present health and importance of an estuary must be considered when determining the ecological flow required to maintain an estuary in its desired state. An Estuarine Health Index that quantifies changes in abiotic and biotic components from natural conditions to present day is used. Health of biotic components is assessed according to changes in species richness, abundance and community composition. There has, however, been debate regarding the calculation of these attributes. In particular, for macrophytes, the inclusion of all habitat within the Estuarine Functional Zone (i.e. 5 m topographical contour) would affect the health and changes over time determined in past assessments. This is due to different areas being included as different areas would be included The aim of this study was to test the validity and suggest improvements to South Africa’s RDM macrophyte health score determination. The health of macrophytes were assessed at varying levels of intensity from desktop studies to thorough field studies. Rapid field studies provided a visual estimate of macrophyte health; while the intermediate and comprehensive assessments quantified change by mapping the distribution of macrophyte habitats from aerial photographs. These approaches were applied to the 64 estuaries within the Mvoti-Mzimkulu Water Management Area (WMA 11), situated in KwaZulu-Natal (KZN) on the subtropical east coast. Historically, these estuaries have supported restricted macrophyte habitats. Consequently, estuaries that presently or historically supported range limited habitats such as mangroves and swamp forest are considered important. Submerged macrophytes are scarce in KZN estuaries due to siltation and low turbidity and thus estuaries supporting this macrophyte habitat are also important. Based on available literature important estuaries were highlighted and selected for field studies. Transects spanning from the estuary water channel to the boundary of the EFZ provided a generalised distribution of KZN vegetation along an elevation gradient. The transition from estuarine to terrestrial vegetation can be used to improve the current EFZ boundaries, as estuarine area has been found to occur outside of the 5 m contour in some estuaries. Results from the desktop assessment indicated that most of the estuaries are moderately modified. There was a 50 % similarity in the macrophyte health scores determined by the desktop assessment to the 2011 National Biodiversity Assessment (NBA). Field studies mostly confirmed the desktop assessment aside from seven estuaries that had different scores. There has been a significant loss of macrophyte habitat with 100% loss of certain habitats from 9 of the 22 estuaries for which there were field assessments. Submerged macrophytes were not found at any of the estuaries that were assessed in the field. Black mangroves, Bruguiera gymnorrhiza (L.) Lam., were rediscovered at Ngane Estuary, however the few individuals could not be considered a ‘mappable’ community (i.e. <0.5 ha). Mtamvuna and Mkomazi estuaries both supported small stands of mangroves that, compared to data from 2006, appeared healthy. Macrophyte habitats and surrounding coastal forest matched the species composition described in the Vegetation Map of South Africa. The freshwater mangrove or Powder puff tree, Barringtonia racemosa (L.) Roxb, was not abundant in the estuaries. It was only found at four (Damba, Fafa, Little Amanzimtoti and Mvoti) of the estuaries that were assessed in the field. Important estuaries, from a botanical perspective, included some of the larger estuaries such as Mgeni, Durban Bay and Sipingo. Smaller, healthier estuaries that presently support mangrove and swamp forest habitat were also identified as important from a botanical perspective. Macrophyte habitats have mainly been lost due to non-flow related pressures. Sugarcane cultivation occurred within the floodplain of 25% of the estuaries. Nutrient enrichment was evident for 12.5% of the estuaries and reed encroachment was evident for 27% of estuaries for which there were field assessments. Development, aside from the N2 road bridges, was evident for 40% of the estuaries assessed in the field. Invasive plant species, including aquatic invasive plants, were present in all estuaries assessed in the field. The extent of invasive plant species was related to the degree of disturbance and surrounding land use pressures. The Mkomazi and Mvoti estuaries that were assessed at a comprehensive level, as they have earmarked for further water abstraction, had the poorest macrophyte health scores. The macrophyte health of these estuaries was much lower than previously determined by the NBA. The decline in health was attributed to the removal of macrophyte habitat for sugarcane cultivation and development as well as displacement by invasive plant species. The areas covered by the macrophyte habitats also differed from the NBA highlighting the importance of updated mapping and ground truthing. Largely differing macrophyte health scores were produced when attributes were calculated using different combinations of macrophyte habitats. Results indicate that only macrophyte habitats and no other floodplain vegetation should be included when calculating abundance. All macrophyte habitats, physical habitats and floodplain should be incorporated when calculating community composition. The minimum of these attributes is used as the overall macrophyte health score as a precautionary approach is followed. Scoring of health is subjective and the only benchmark for determining the most appropriate method is comparion with previous RDM studies. This study illustrates the need for a standardised RDM scoring method that is presented in a manner that ensures the same results irregardless of the speciliast conducting the study. The updated estuary health and importance scores for WMA 11 are necessary to inform management, particularly as few of the estuaries receive formal protection. In conclusion, this study contributed to the limited knowledge of the estuaries of WMA 11 and assisted in determining appropriate methods for assessing the health and importance of estuary macrophytes.

Knowledge management is largely a social process. It is more about the community‘s understanding, skills and values in relation to their practices than technology. Knowledge is generated and shared through social interaction of people. Exploring the community‘s acts of communication and interaction can help to understand the knowledge they have as well as the knowledge gaps that are apparent. It can also aid in discovering ways in which their practices are shaped and constrained by the knowledge they have. The purpose of this study was to determine the optimal means of knowledge sharing and knowledge distribution in an open system using the Eastern Cape Tyolomnqa Estuary as a case study. Different scholars stated in their different works that sharing knowledge is problematic in most organizations, whether they are formal or informal organizations. There are several reasons that have been identified as to why people do not want to share their knowledge. To achieve the objectives of this study, both secondary and primary sources of data were used. This included literature from various sources, such as books, journal articles and information from the Internet that has been reviewed and analyzed. Interviews and focus groups were used to collect data. Interviews were conducted with 16 people who were purposively selected from the Buffalo City Council, Tyolomnqa Conservancy, Tyolomnqa Estates, Tyolomnqa Forum, and Phozi, Ncera, Sandile and Xhama communities. The key informants were people with management positions, and community leaders. The interviews were unstructured. After collecting data by means of face-to-face interviews focus groups, workshops were convened with the Tyolomnqa Forum, and Phozi, Ncera, Sandile and Xhama communities. The self-administered questionnaire was additionally used as a data collection technique for researchers. Data were analyzed through content analysis and the use of SPSS, and presented in the form of tables and figures. It was identified that their knowledge sharing was fragmented and there was no formal organisational structure to bring communities along the Tyolomnqa Estuary to work together as one would do in bureaucratic organizations like companies. The Tyolomnqa Estuary Forum, which has vested interests in estuary management, could be used as model to provide the organisational infrastructure to facilitate the acquisition and sharing of knowledge on the management of estuaries. It is envisaged that such forums can be a viable mechanism of facilitating the harnessing and sharing of knowledge on the sustainable use of estuaries at the local level. / Thesis (M.I.S.)-University of Natal, Pietermaritzburg, 2003.

Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2007. / In South Africa, as a result of limited resources and capacity, the governance and management of estuaries occur on an ad hoc basis, with decisions about an estuary’s freshwater-flow requirements, water quality, living-resources management, mouth management and protection status being made on a largely uncoordinated and non-strategic basis. This study is aimed at developing an understanding of the opportunities and constraints affecting estuarine management at a regional scale. The objectives of this study were to: 􀂃 Review relevant policy and legislation governing estuarine management in South Africa; 􀂃 Discuss the current status of regional estuarine management in South Africa; 􀂃 Review international literature for potentially applicable management guidelines; 􀂃 Construct a management protocol for estuarine management in South Africa; 􀂃 Apply this protocol in a South African setting; and 􀂃 Recommend improved measures for regional estuarine management. The main outcome of the study was the development of the proposed National Estuarine Management Protocol, which is currently in the process of being incorporated into the National Environmental Management: Coastal Zone Bill. The CAPE Estuaries Programme was developed to test the proposed Protocol in a regional setting. The study concluded that there was an urgent need for a more holistic regional approach to estuarine management but that the proposed framework and protocol would be successful only if, in addition, they were supported by an understanding of the biophysical estuarine processes and management constraints operating at the local level.

Larval fish and zooplankton assemblages were studied in nine south and west coast estuaries in the cool-temperate and the cool/warm-temperate boundary region between June 2003 and March 2004. This study served to provide new information on previously unstudied estuaries and expand on existing knowledge of larval fish and zooplankton assemblages associated with various estuary types. The south and west coast estuaries sampled in this study showed lower salinities (12.2 - 13.7), lower water temperatures (14.5 - 16.9 °C) and higher turbidities (k = 0.02 - 0.04) in winter and spring while higher salinities (21.7 - 21.8), higher water temperatures (21.7 - 23.1°C) and lower turbidities (k <0.02) were observed in summer and autumn. Mean winter and summer water temperatures in estuaries were lower than those observed in warm-temperate and subtropical systems by other researchers. A total of 49274 larval fishes were caught, comprising 9 orders, 20 families, 29 genera and 47 taxa. The clupeid Gilchristella aestuaria (78.8 %) dominated the larval fish assemblages and occurred in all estuaries. The majority (70 %) of identified species are endemic to southern Africa and 96.4 % of larval fishes caught were estuary-resident species. The zooplankton study yielded a total of 44 taxa, comprising 7 phyla, >20 orders and >35 families. The copepod Pseudodiaptomus hessei dominated (59 %) the zooplankton and occurred in similar densities to those observed in other South African estuaries. Larval fish and zooplankton varied across seasons, peaking simultaneously in summer although zooplankton showed additional density peaks during the closed phase of some estuaries. Both plankton components were more abundant in the oligohaline and mesohaline zones within the estuaries. Freshwater input, estuary type and the biogeography of the area influenced the composition and structure of larval fish and zooplankton assemblages in these estuaries. The findings suggest that the estuaries are functioning as successful breeding areas for the larvae of endemic estuary-resident fish species and that these estuaries have to be managed to ensure an adequate freshwater supply to maintain the biological integrity of the ecosystem, specially the maintenance of the highly productive River-Estuary Interface (REI) regions.

The larval fish and zooplankton assemblages were studied in the permanently open Sundays Estuary on the south-east coast of South Africa, using standard boat-based plankton towing methods. A total of 8174 larval and early juvenile fishes were caught, representing 12 families and 23 taxa. The Clupeidae, Gobiidae and Blenniidae were the dominant fish families. Common species included Gilchristella aestuaria, Caffrogobius gilchristi, Omobranchus woodi, Liza dumerilii, Glossogobius callidus and Myxus capensis. Estuarine resident species (Category I) predominantly in the preflexion developmental stage, dominated the system. A total of 19 zooplankton taxa were recorded. Copepoda dominated the zooplankton community. Dominant species included Pseudodiaptomus hessei, Acartia longipatella, Halicyclops sp., Mesopodopsis wooldridgei, and the larvae of Paratylodiplax edwardsii and Hymenosoma orbiculare. Mean larval fish density showed similar trends seasonally, spatially and across salinity zones, with mean zooplankton density in the Sundays Estuary. Gut content analysis of five larval fish species: Gilchristella aestuaria, Pomadasys commersonnii, Monodactylus falciformis, Myxus capensis and Rhabdosargus holubi, revealed species specific diet and prey selection. Although larval fish diet contained a variety of prey items, guts were dominated by P. hessei, chironomid larvae, Corophium triaenonyx, copepod eggs and insect larvae. Physico-chemical drivers and the interactions between these two plankton communities provide information that enables a more holistic view of the dynamics occurring in the Sundays Estuary planktonic ecosystem.

Estuaries are irreplaceable natural resources that must be managed carefully for the mutual benefit of all who enjoy and depend on them. The estuarine environment is a very dynamic and complex environment, which poses threats and challenges to estuary managers and estuary users. As estuarine management is a very knowledge-intensive task, researchers in the Eastern Cape Estuaries Management Programme (ECEMP), estuary managers and estuary users have recently turned their attention to knowledge management as one of the important means of ensuring continued success and effective management of estuaries. However, knowledge management as an emerging field has been slow in formulating universally accepted methodologies for auditing, capturing, creating, acquiring, sharing and utilising knowledge. Existing methodologies do not adequately address, in particular, the knowledge audit requirements of non-traditional or non-constrained and non-formalised organisations. The purpose of this study was to develop a context-specific model for auditing knowledge in the Eastern Cape estuaries, with special reference to the Tyolomnqa Estuary. The study intended to identify the knowledge community, analyse existing knowledge and knowledge needs and gaps in the Tyolomnqa Estuary area. In order to achieve the objectives, the descriptive research design, employing the case study approach was used in the study. Focus groups and unstructured interviews were used to collect data. A literature review, concentrating on values and issues surrounding the management of estuaries and key issues in knowledge management and knowledge auditing, was carried out. The collected data was analysed according to themes such as knowledge sources, knowledge identification and knowledge needs and gaps. The study found that the communities of the Tyolomnqa Estuary lack knowledge concerning the management of estuaries. The study also established that the community has little knowledge on who to contact for expert advice in addressing estuarine issues. Furthermore, the study found that the community needed knowledge on how to address estuarine management issues and how that knowledge could be accessed. Based on the findings and the literature review, the study proposes a context-specific knowledge audit model for non-traditional organisations. The model is meant to assist non-traditional organisations to evaluate their knowledge health or status, and to develop a much better understanding of the know-how and how it can be used to effectively sustain their services. The model can be used to successfully implement knowledge management strategies in non-traditional organisations. The model needs to be tested for verification and validation purposes. / Thesis (M.I.S.)-University of KwaZulu-Natal, Pietermaritzburg, 2003.