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Relevant bibliographies by topics / Estuarine ecology – South Africa – Swartvlei / Dissertations / Theses

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Dissertations / Theses on the topic 'Estuarine ecology – South Africa – Swartvlei'

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Published: 4 June 2021

Last updated: 6 February 2022

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1

Roets, Adriaan. "A preliminary analysis of the sediment budget across the Swartvlei estuary mouth." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95958.

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Thesis (MEng)--Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: The Swartvlei estuary and lake system is situated on the southern coast of the Western Cape Province of South Africa and forms part of the core conservation area of the Wilderness National Park. The Swartvlei system comprises two interlinked water bodies, namely Swartvlei Lake and Swartvlei estuary. SANParks have been monitoring this estuary closely over the past two decades, due to its importance to the ecology and to tourism. There are also low-lying properties on the perimeter of the Swartvlei estuary which run the risk

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Roos, Aneri. "Perspectives of stakeholders on engagement around benefits and use of the Wilderness and Swartvlei lakes." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/6588.

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The objective of this research was to determine how stakeholder engagement impacts on the use and sharing of ecosystem service benefits derived from large lake systems. The Wilderness and Swartvlei lake systems, which form an integral part of the Wilderness Section of the Garden Route National Park (GRNP), were chosen as the study area. The park is juxtaposed with urban and other land uses making it one of the most integrated urban conservation areas in South Africa. The park is an open-access park with only enclosed areas being the camping and chalet areas that borders onto the Touw River Est

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3

Snow, Gavin Charles. "Contributions to the use of microalgae in estuarine freshwater reserve determinations." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/709.

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The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each

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4

Veldkornet, Dimitri Allastair. "Morphological variation and species diversity of South African Estuarine macrophytes." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1013001.

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Studies on morphological variation are important as it can depict the relationship with environmental factors clearly and convey an understanding of the manner, mechanism and factors influencing plant adaptation and evolution. Although many studies have been conducted on South African salt marsh plant physiology and phytosociology there are at present very few morphological studies on estuarine plants. The aim of this study was to compare the morphological variation of estuarine macrophytes in three different estuary types in the warm temperate biogeographic zone of South Africa and to compare

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5

Strydom, Nadine Amelia. "Dynamics of early stage fishes associated with selected warm temperate estuaries in South Africa." Thesis, Connect to this title online, 2002. http://eprints.ru.ac.za/25/.

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6

Masefield, Vincent Antony. "A preliminary assessment linking altered catchment land-cover to the health of four temporarily open/closed South African estuaries." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013096.

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Estuaries worldwide are being subjected to various degrees of catchment degradation, which is having severe consequences on the integrity of these aquatic ecosystems and their ability to function properly. This thesis investigated the relationship between catchment land-cover and estuarine health in four temporarily open/closed estuarine systems (TOCEs) in South Africa, namely the Groot Brak, East Kleinemonde, Mdloti and Tongati. GIS techniques were employed to delineate catchments, lower sections of catchments, 1 km and 100 m buffer zones, and to quantify the extent of land-cover classes pres

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7

Norton, Olivia Bridget. "The population structure of two estuarine fish species, atherina breviceps (Pisces: Atherinidae) and gilchristella aestuaria (Pisces: Clupeidae), along the Southern African coastline." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1005431.

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Phylogeographic patterns of coastal organisms with different life histories and breeding strategies may reveal patterns not consistent with the current delineation of the biogeographic provinces around South Africa. The subdivision of the South African coastline into these three main climatological or biogeographic regions: namely the cool temperate west coast, the warm temperate south coast and the subtropical east coast, is based on average seawater temperatures and hydrological conditions. Genealogies of two estuarine fish species Atherina breviceps, a marine breeder, and Gilchristella aest

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8

Akoto, William. "Valuing preferences for freshwater inflows into selected Western and Southern Cape estuaries." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/915.

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An estuary is the last stage of a river. It is where the river meets the sea. Estuaries are one of the most significant features of the South African coastline. In recent years, South Africa has witnessed an increase in the demand for freshwater for both industrial and domestic purposes. At the same time, there has been a gradual deterioration of river systems and their catchments. To add to this, there has been a gradual reduction in the amount of recorded rainfall, which is the primary source of freshwater for rivers. This has resulted in decreased freshwater inflow into estuaries, a situati

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9

Bergamino, Roman Leandro. "Spatial and temporal variations in trophic connectivity within an estuarine environment : benthic-pelagic and terrestrial-aquatic linkages via invertebrates and fishes." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017799.

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Estuarine ecosystems are among the most biologically productive areas and they provide important ecosystem services such as erosion control, habitat and refugia for several species. These environments are characterized by the presence of a variety of organic matter sources due to their transitional position between rivers and the sea. The biotic compositions can undergo spatial and seasonal changes along the estuary due to the spatial and temporal fluctuations of environmental factors such as salinity, temperature and seston loads. Therefore, the different combinations of biotic and abiotic fa

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10

Harrison, Trevor D. "Biogeography and community structure of fishes in South African estuaries." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1005078.

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The biogeography and community structure of the fishes of South African estuaries was investigated. In all, 109 systems were examined representing two broad types: temporarily closed and permanently open estuaries. Multivariate analyses of the fish communities identified three biogeographic regions. A cool-temperate region extended along the west and southwest coasts; a warmtemperate zone stretched along the south, southeast and east coasts and a subtropical region occurred along the east coast. The boundaries of these biogeographic regions were also delineated. The general physico-chemical ch

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11

Veldhuis, Helen Anne. "An analysis of factors controlling the distribution of zooplankton in the Knysna estuary, South Africa." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/22015.

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The Knysna estuary system, on the south coast of South Africa, was sampled for zooplankton over period of one year. All species were recorded and an attempt was made at relating the distribution of populations to physical factors within the estuary. Over 50 species were identified. Pseudodiaptomus hessei, Acartia(Paracartia) longipatella and A.(Acartiella) natalensis were the dominant copepods in the upper estuary. Paracalanus spp. were dominant near the mouth. Zooplankton distribution was found to be related to tidal exchange. The zooplankton displayed a seasonal cycle of abundance, with maxi

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12

Kaambo, Eveline. "Investigation of South African estuarine microbial species and genome diversity." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8171_1186398717.

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<p>A study of the microbial diversity in sediments of the Great Berg River estuary is carried out using modern molecular phylogenetic methods. The aim of this study was to determine the effect of (pollution by) the effluents of the fish industry on the composition of the microbial community in the sediments. The diversity in microbial groups of sediment samples that received wastewater from the local fishing industry was investigated by a PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) approach and compared to an unaffected site.</p>

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13

Muller, Cuen. "Evaluating the importance of mangroves as fish nurseries in selected warm temperate South African estuaries." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/12080.

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The value of mangrove habitats as fish nurseries was assessed by comparing communities of early stage and juvenile fishes between estuaries with and without mangroves. Early stage fishes were sampled using boat-based plankton towing while juveniles were sampled by seine netting. Sampling took place at five sites spaced 1 km apart starting near the estuary mouth in four estuaries along the temperate coastline of the Eastern Cape Province of South Africa. Four estuaries were selected based on shared similarities which included catchment area, estuarine area and shared habitats barring the presen

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14

Harrison, Trevor D. "Ecology of the ichthyofauna in three temporarily open/closed estuaries on the Natal coast." Thesis, Rhodes University, 1994. http://hdl.handle.net/10962/d1005113.

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The ichthyofauna of three small Natal estuaries, the Mhlanga, Damba and Zotsha was sampled over a period of two years. A total of 68 kinds of fishes representing 24 families, 39 genera and 56 species were captured during this study. Forty seven kinds of fishes were recorded in the Mhlanga of which Gilchristella aestuaria,Oreochromis mossambicus, Valamugil cunnesius, Valamugil sp. and juvenile mugilids numerically dominated. In terms of biomass, O. mossambicus, V. cunnesius, Liza alata, Myxus capensis and Mugil cephalus dominated the ichthyofauna of the Mhlanga. In the Damba, 24 kinds of fishes

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15

Kaselowski, Tanja. "Physico-chemical and microalgal characteristics of the Goukamma Estuary." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1011130.

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Estuaries are intrinsically complex and dynamic ecosystems that display marked spatial and temporal variability. Because estuaries are situated at the receiving end of catchment activities, they are at particular risk of alterations to their natural complexity. The overarching objective of this study was to gain an overview of the abiotic conditions and biotic response of the Goukamma Estuary, a small temporarily open/closed estuary (TOCE) which is situated in a relatively undisturbed catchment in the Southern Cape. Physico-chemical properties drive estuarine ecology, and together with biologi

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16

Paterson, Angus William. "Aspects of the ecology of fishes associated with salt marshes and adjacent habitats in a temperate South African estuary." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1013010.

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There is a paucity of published information on fish utilization of salt marshes outside North America. This dissertation represents the first intensive examination of the ichthyofauna associated with salt marshes in southern Africa and examines the species composition, diversity, size structure, distribution and estuarine dependence of fishes that utilize salt marshes in the Kariega Estuary. The research was concentrated on Taylor's salt marsh, with comparative studies being conducted on other salt marshes and habitats within the marine dominated Kariega Estuary. The possible importance of sal

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17

Bezuidenhout, Chantel. "Macrophytes as indicators of physico-chemical factors in South African Estuaries." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1387.

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This study investigated the response of macrophytes to physico-chemical factors in seven South African estuaries and showed that dominant salt marsh species that occur in different estuaries respond to the same environmental factors. The most important variables influencing distribution were elevation, water level, sediment- and groundwater electrical conductivity and depth to the water table. In permanently open estuaries (Kromme and Olifants) transect surveys identified three distinct vegetation zones i.e. submerged macrophytes, intertidal salt marsh and supratidal salt marsh. In the Kromme

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18

Cowley, Paul D. (Paul Denfer) 1964. "Fish population dynamics in a temporarily open/closed South African estuary." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1008543.

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The primary aim of this study was to investigate the population dynamics of the fishes associated with a small (17.5 hectares) temporarily open/closed estuary on the south east coast of South Africa. The results are based on the findings of an intensive sampling programme conducted over a period of four years in the East Kleinemonde estuary (33° 32' S : 27° 03' E). By adopting a quantitative approach, this study addresses the need for information on estuarine-associated fish population sizes, standing stock (biomass) estimates and productivity. The ichthyoplankton assemblage in the surf zone a

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19

Chege, Jedidah. "Valuing preferences for freshwater inflows into five Eastern Cape and Kwazulu-Natal estuaries." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/932.

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An estuary, according to the National Water Act of 1998, is a partially or fully enclosed body of water which is open periodically or permanently to the sea within which the sea water can be diluted, to an extent that is measurable with freshwater from inland. Estuaries and the lands surrounding them are places of transition from land to sea, and from freshwater to saltwater. Although influenced by the tides, estuaries are protected from the full force of ocean waves, winds, and storms by the reefs, barrier islands, or fingers of land, mud, or sand that surround them. South Africa’s estuaries

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20

Van, der Westhuizen Henri. "Valuing preferences for freshwater inflows into the Bira, Bushmans, Kasouga, Keiskamma, Kleinemond East, Nahoon and Tyolomnqa estuaries." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/628.

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There are about 259 estuaries in South Africa that can be classified as “functioning” and their “health” status is directly related to the quantity and quality of freshwater that flows into them. Many of South Africa’s estuaries have become smaller due to a steady decrease in the amount of freshwater that flows into them. This reduction in freshwater inflows decreases their ecological functioning and undermines the recreational activities and subsistence services available from them. The National Water Act (ACT No. 36 of 1998) recognises the right of the environment to water, but a large amoun

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21

Vorsatz, Jeanne Pauline. "Ecological role of estuarine brachyuran crabs in mangrove and salt marsh estuaries, Eastern Cape, South Africa." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1108.

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Crabs are conspicuous inhabitants of temperate salt marshes and tropical mangroves and interact with their environment through several processes. However, detailed information on crab community processes is absent for most South African estuaries and nearshore coastal regions. This study evaluated the primary producers supporting crab species in the salt marsh dominated Swartkops estuary and the mangrove Mngazana estuary. Various methods estimating crab abundances were also assessed in different microhabitats and the larval distribution of crabs in the coastal zone was also investigated. Vario

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22

Montoya-Maya, Phanor Hernando. "Dynamics of larval fish and zooplankton in selected south and west coast estuaries of South Africa." Thesis, Rhodes University, 2009. http://eprints.ru.ac.za/1641/.

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23

Tweddle, Gavin Paul. "Population dynamics of selected ichthyofaunal components in the temperate, temporarily open/closed Kasouga Estuary, South Africa." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1005428.

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The spatial and temporal pattern of ichthyofaunal community composition in relation to selected physico-chemical (temperature and salinity) and biological variables (chlorophyll-a and zooplankton) was investigated at ten stations in the temperate temporarily open/closed Kasouga estuary. In addition, the food web structure in the estuary was investigated using stable carbon isotope analysis. Results of the 5 metre seine net survey indicated that ichthyofaunal composition and biomass in the Kasouga estuary was largely determined by seasonality and mouth condition. Maximum abundance and biomass o

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Cowie, Meredith. "Environmental flows, health and importance of macrophytes in the estuaries of water management area 11." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/7930.

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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

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25

Henninger, Tony Oskar. "Aspects of the ecology and biology of the isopod, Exosphaeroma hylocoetes, (Barnard, 1940) in three temporarily open/closed southern African estuaries." Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1005322.

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Temporarily open/closed estuaries (TOCE’s) are the numerically dominant type of estuary accounting for ≈ 70 % of all estuaries along the South African coastline. Despite their numerical dominance, aspects of the biology of organisms within these systems, particularly macrocrustacea remain poorly understood. This study firstly assessed the abundance and biomass of the most common isopod, Exosphaeroma hylocoetes, in three Eastern Cape TOCE’s, (the West Kleinemonde, East Kleinemonde and Kasouga Estuaries), and their response to mouth breaching events. This study was followed by aspects of the bio

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Jafta, Nolusindiso. "The botanical importance and health of the Bushmans estuary, Eastern Cape, South Africa." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1255.

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The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators f

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Gama, Phumelele Thuthuka. "Phytoplankton chlorophyll a concentration and community structure in two temporarily open/closed estuaries in the Eastern Cape, South Africa." Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/707.

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River flow is important in controlling phytoplankton distribution in estuaries. Data on the effect of river inflow on phytoplankton distribution patterns in temporarily open/closed estuaries is lacking. This study investigated the influence of river inflow on size-fractionated phytoplankton biomass (Chl a), community composition and environmental parameters measured monthly over three years in two temporarily open/closed estuaries in the Eastern Cape, South Africa. A once-off primary production study over an annual cycle was completed in the Van Stadens and Maitland estuaries. The study monito

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Vosloo, Mathys Christiaan. "Network analysis of trophic linkages in two sub-tropical estuaries along the South-East coast of South Africa." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1010966.

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Estuaries are some of the most productive yet threatened ecosystems in the world. Despite their importance they face significant threats through changes to river flow, eutrophication, rapid population growth long the caost and harvesting of natural resources. A number of international studies have been conducted investigating the structure and functioning of an array of ecosystems using ecological network analysis. Energy flow networks have been contsructed for coastal, lagoonal, intertidial and, most notably, permantently open estuaries. Despite the valualble insights contributed by these and

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Nsubuga, Yvonne Nakalo. "Towards sustainable utilisation of the fishery resources of the Kowie Estuary, South Africa." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1007154.

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The annual biomass of fish caught from estuaries in South Africa is currently estimated at over 24,800 tons. These estuarine fishes are caught by over 73,000 fishers, most of them recreational. Annual income derived from South Africa’s total estuarine fishery was worth approximately R430,000,000 in 1997. There is increasing concern that unless our estuarine fisheries are effectively managed, we will not be able to sustain these benefits into the future. Two factors that contribute to inadequate management of the estuarine fisheries in South Africa are a lack of data on which to base management

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Deyzel, (Shaun) Herklaas Phillipus. "Mesozooplankton dynamics in a biogeographical transition zone estuary." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1007901.

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This thesis presents the first intensive community-level investigation of the mesozooplankton from a biogeographical transition zone estuary. The Mgazana Estuary is located along a rural, semi-undeveloped part of South Africa’s east coast, believed to represent a transition zone between the subtropical and warm-temperate biogeographical zones. The research represented in this thesis involves data collected over a five year period between 2002 and 2006, with additional data collection made in 2008. The study focussed on five areas of investigation, the first of which investigated the physico-ch

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Sheppard, Jill Nicole. "Structure and functioning of fish assemblages in two South African estuaries, with emphasis on the presence and absence of aquatic macrophyte beds." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1005166.

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Temporarily open/closed estuaries (TOCEs) are the dominant estuary type in South Africa. These systems are often characterized by extensive beds of submerged macrophytes, which form important foraging and shelter habitats for fishes, especially for estuary-dependent fish species such as the Cape stumpnose Rhabdosargus holubi and Cape moony Monodactylus falciformis that are commonly associated with them. A loss of submerged macrophytes from an estuary has been shown to affect the fish community as well as reducing overall system productivity. The TOC East Kleinemonde Estuary, situated in the wa

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Naidoo, Lyndle Sherae. "Identification and classification of micro-estuaries using selected abiotic and biotic characteristics along the Eastern Cape coast, South Africa." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/11920.

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Many of the larger estuaries along the South African coastline are highly degraded due to human impacts, highlighting the need to conserve pristine systems. There are approximately 100 micro-estuaries along our coastline which have not yet been identified or classified and hence their ecological functioning is unknown. The aim of this study was to identify and classify micro-estuaries along the Eastern Cape coast. Specific objectives of the study were to: 1) map the distribution of estuarine habitats in a selection of micro-estuaries and assess changes over time; 2) measure the physico-chemica

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Groenewald, Christoff J. "Macrobenthic community structure across an inter- and subtidal gradient in a mangrove estuary." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1240.

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Macrozoobenthic community structure and composition was investigated along a subtidal-intertidal gradient in the Mngazana Estuary. Six transects were sampled between the spring high water mark (HWST) and the bottom of the river channel in the lower estuary. Fifteen replicate samples were collected along each transect using a Van Veen type grab (211 cm2 bite) during each of three sampling sessions. Samples were sieved through a 500 μm mesh bag and the invertebrates stored in bottles for further analysis in the laboratory. Additional grab samples were collected for sediment particle size analysi

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Nunes, Monique. "Microalgae and macrophytes as indicators of ecological health in the Great Brak Estuary." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1012097.

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The Great Brak temporarily open/closed estuary was subjected to a drought during the spring and summer of 2009/2010 resulting in the mouth remaining closed for a prolonged period. According to the Great Brak Estuary management programme, the mouth of the estuary had to be open for a total of 308 days during spring and summer of 2009/2010, respectively, but was closed for almost the entire two years (693 days). The aim of this study was to assess monthly changes in the abiotic characteristics (salinity, temperature, oxygen, pH and nutrients) and the biotic responses of phytoplankton and macroal

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Snook, Deborah Jane. "Some aspects of the autecology of Rhizoclonuium riparium (Roth) Harv. with special reference to its growth in the maturation ponds of the Grahamstown sewage works." Thesis, Rhodes University, 1986. http://hdl.handle.net/10962/d1004724.

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During 1982 benthic and floating filamentous algal mats appeared in the maturation ponds of the Grahamstown Sewage Disposal Works. These mats clogged the ponds and reduced the efficiency by which the effluent was purified. As they continued to be a problem despite numerous efforts to remove them, this study was initiated to investigate the alga, establish why it was successful in the pond environment, and how its growth could be controlled. The physico-chemical environment of a representative maturation pond was characterised while laboratory studies were conducted to investigate the growth, p

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Grant, Walter Lawrence. "The community structure and feeding ecology of the ichthyofauna in the Mngazana and Mngazi estuaries, Port St. Johns, South Africa." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/513.

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The Mngazana and Mngazi estuaries are situated just south of Port St. Johns close to the biogeographical boundary between the warm temperate and subtropical zones along the east coast of Southern Africa. The Mngazana estuary is a permanently open estuary with three species of mangrove. The Mngazi estuary is a temporarily open/closed system. The ichthyofauna was sampled with seine nets and gillnets during June 2005, August 2005, November 2005, February 2006 and April 2006. The fish community structure was significantly different between the two estuaries with the differences being especially no

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James, Nicola Caroline. "Trends in fish community structure and recruitment in a temporarily open/closed South African estuary." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1005178.

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Long-term interannual changes in richness, abundance, diversity and structure of the fish community in the temporarily open/closed East Kleinemonde Estuary, Eastern Cape, are described and the recruitment success of two estuary-dependent marine species assessed. In addition, laboratory experiments were conducted to assess the possible role of olfaction in the recruitment process of an estuary-dependent marine fish species. Multivariate analyses of the annual marine fish communites identified two distinct groups with more species recorded during years that succeeded spring (September to Novembe

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Sutherland, Kate. "The dynamics of Larval fish and Zooplankton assemblages in the Sundays Estuary, South Africa." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1119.

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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 st

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Vorwerk, Paul D. "A preliminary examination of selected biological links between four Eastern Cape estuaries and the inshore marine environment." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1005434.

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The coastal transition zone (CTZ), which links the terrestrial and marine environments, has been identified as a region of high biological diversity and elevated production. Results of studies conducted in the northern hemisphere indicate that the links between estuaries and the adjacent marine environment is critical to ecological functioning within the CTZ. This study assessed the influence of selected estuaries with different hydrodynamic characteristics on the adjacent marine environment along the south-eastern coastline of southern Africa. Four estuaries were examined, including two perma

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Ngesi, Hlekani Ntombizakithi. "Microalgal biomass and distribution in the Mngazi and Mngazana Estuaries." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1591.

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The present study was undertaken in the temporarily open/closed Mngazi and permanently open Mngazana estuaries, located on the subtropical east coast of South Africa. The results from this research will assist decision makers in the freshwater management of these systems. Intertidal and subtidal benthic chlorophyll a concentrations, water column chlorophyll a, nutrients and several physico-chemical parameters were measured between June 2002 and November 2003. The objective of this study was to determine if the presence of freshwater in the estuaries had an effect on the microalgae of both estu

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Vromans, Deborah Claire. "Macrophyte phenology in a temporarily open/closed Estuary compared with a permanently open Estuary." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1393.

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Temporarily open/closed estuaries (TOCEs) are unpredictable environments that change in response to mouth condition, which is influenced by freshwater flooding or sea storm surges. The aim of the study was to determine whether macrophyte phenology in a TOCE was event driven rather than cyclically predictable and if it differed from permanently open estuaries (POEs). Macrophyte growth and flowering phenology in response to environmental conditions was investigated in the East Kleinemonde Estuary (TOCE) and the Kowie Estuary (POE) along the eastern coastline of South Africa. The lack of freshwat

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Prinsloo, Shireen. "The distribution and diversity of macroalgae in selected estuaries along the Eastern Cape coast of South Africa." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1012314.

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The growth and accumulation of macroalgae in estuaries are a common sight throughout the world (Boyer and Fong, 2005). Because macroalgae establish such complex but important links with other components within an estuary, it is essential to know which variables control and regulate their occurrences. The type of algae that will occur in an estuary depends however, on the physical and chemical features of the particular estuary (Lobban and Harrison, 1994). The focus of this study was to document and provide a listing of algae from estuaries around the Eastern Cape coast of South Africa and desc

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Richardson, Naomi. "A preliminary investigation into the use of biomarkers and a fish community index to assess estuarine health in selected Eastern Cape estuaries." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1007480.

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The aims of this study were to determine the potential use of biomarkers at multiple levels of biological organisation together with a fish community bioindicator to assess the estuarine health status of three temporarily open/closed estuaries. The estuaries investigated were the East Kleinemonde (EK), Old Woman's (OW) and Mtana (MTN), all of which are situated in the Eastern Cape Province. Three biomarkers, the acetylcholinesterase (AChE) assay, lipid peroxidation (LPx) assay, liver histopathology and a condition factor were used to determine sub-organism health and one bioindicator, the Estu

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Louw, Liezel. "The zooplankton of Mngazana estuary." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/702.

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The zooplankton community of the main channel of the Mngazana estuary was investigated on six occasions over one year. Spatial and temporal variability in zooplankton abundance and distribution were sampled using two slightly modified WP2 plankton nets of 200 μm mesh and 57 cm mouth diameter. Nets were fitted with calibrated Kahlsico 005 WA 130 flow meters. A set of environmental variables were also measured at each site. The water column of the main channel of Mngazana estuary was stratified in summer but well mixed in winter. Temperature progressively increased from the lower stations to the

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Pretorius, Liaan Marié. "Spatial and temporal variability in water quality characteristics of the Swartkops Estuary." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/4176.

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Water quality characteristics of the heavily urbanised and industrialised Swartkops River catchment in the Eastern Cape has been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTW), polluted stormwater runoff and solid waste have had a negative impact on the water quality status of the Swartkops River and estuary. Past studies have revealed that a distinct relationship exists between land use activities and the water quality of the Swartkops Estuary, which in turn has raised concerns pertaining to the ecological, economic, recreation

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Njozela, Cuma. "The role of the sandprawn, Callichirus kraussi, as an ecosystem engineer in a temporarily open/closed Eastern Cape estuary, South Africa." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1001539.

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The role of the sandprawn, Callichirus (=Callianassa) kraussi (Stebbing), as an ecosystem engineer was assessed in the lower reach of the temporarily open/closed Kasouga Estuary situated along the Eastern Cape coastline of southern Africa over the period April 2010 to June 2011. The study comprised two distinct components, a field study and a caging experiment. The field study assessed the correlation between sand prawn densities and selected physico-chemical (organic content of the sediment and bioturbation) and biological (microphytobenthic algal concentrations and macrobenthic abundance and

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Allan, Elizabeth Louise. "Ecological role of free-living bacteria in the microbial food web of the temporarily open/closed East Kleinemonde Estuary, South Africa." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005351.

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The main aim of this study was to assess the “top-down” and “bottom-up” control of bacterial production in the small temporarily open/closed East Kleinemonde Estuary, situated on the south-eastern coastline of southern Africa. Spatial and temporal patterns in bacterial abundance, biomass and production and the importance of abiotic and biotic factors were investigated over the period May 2006 to April 2007. The trophic interactions between bacteria, phytoplankton, nanoflagellates (< 20 μm), microzooplankton (< 200 μm) and mesozooplankton (< 2 000 μm) were investigated during winter and summer.

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Human, Lucienne Ryno Daniel. "The contribution of submerged macrophytes and macroalgae to nutrient cycling in the Great Brak Estuary." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1021102.

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An ecological reserve study by the Department of Water Affairs on the Great Brak Estuary stated that there was a need to determine how much nitrogen and phosphorus was flowing through the estuary as well as how effective the macroalgae were at removing N and P. The objective of this study was to investigate the physico-chemical characteristics in the estuary and the influence of these on the submerged macrophytes and macroalgae. A nutrient budget for the estuary was developed in order to quantify the contribution of the submerged macrophytes and macroalgae relative to other contributing source

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Orr, Kyla Kathleen. "Spatial and temporal variations in metals in the sediment and water of selected Eastern Cape Estuaries, South Africa." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005457.

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The spatio-temporal patterns in concentrations of selected metals within the sediment (Cd, Co, Cu, Fe, Pb, Ni and Zn) and water (Cd and Pb) of three permanently open estuaries (Kariega, Kowie, Great Fish) and six temporary open-closed estuaries (Mpekweni, East Kleinemonde, West Kleinemonde, Riet, Kasouga, Boknes) were investigated. The concentrations of metals were influenced by size composition and total organic content of the sediments. Enrichment factors (EFs), using Fe as a reference element, and baseline linear regression models for metals vs. Fe were calculated to assess the extent of me

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Jooste, Jakobus Gerrit. "An assessment of bait availability, utilization and management guidelines in Eastern Cape estuaries." Thesis, University of Port Elizabeth, 2003. http://hdl.handle.net/10948/334.

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Aspects around the management of benthic soft sediment bait organisms, with special focus on the mud prawn (Upogebia africana) of eastern Cape estuaries was investigated. The recreational linefishery of the Gamtoos estuary was described, and compared to previous studies. Target fish species was identified, and a large dependency on bait sourced from estuaries needed for the capture of these species was noted, especially for spotted grunter (Pomadasys commersonnii). A comparison between bait use, success and the natural diet of target fish species was also made. The structure and distribution o

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