Open Access

Konturite, also Sedimente die durch persistente Bodenströmungen abgelagert oder maßgeblich beeinflusst wurden, sind Archive für paläozeanografische und damit einhergehende paläoklimatische Veränderungen. Sie stehen im Fokus intensiver multidisziplinärer Forschung und können in den heutigen Ozeanen, vor allem dank schiffbasierter geophysikalischer Methoden, weiträumig nachgewiesen werden. Die Identifikation fossiler Konturite an Land bleibt jedoch eine Herausforderung, und neue Fallstudien zur Dokumentation der Sedimentfazies sind selten. Dies ist auf noch immer unvollständige Kriterien zur Identifikation von Konturiten im kleinen Maßstab zurückzuführen. Nur die Kombination klein-, mittel- und großskaliger Kriterien ermöglicht die eindeutige Identifikation fossiler Konturite. Unzureichende Aufschlussqualität und -größe schränken diesen Ansatz jedoch häufig ein und damit die Möglichkeit, Konturite eindeutig als solche zu erkennen und als paläoozeanographische Archive auswerten zu können. Insbesondere die Dokumentation der Variabilität einzelner Konturit-Sequenzen im kleinen Maßstab, beispielsweise mittels Mikrofazies-Analyse, ist grundlegend für die Erarbeitung zuverlässigerer diagnostischer Kriterien und besitzt demzufolge hohe Priorität. Die vorliegende Arbeit adressiert dieses Ziel mit der Untersuchung des Einflusses von Bodenströmungen auf Karbonatabfolgen des Devons, die im tiefmarinen Ablagerungsraum zwischen den konvergierenden Großkontinenten Laurussia und Gondwana akkumuliert wurden. Solche Abfolgen sind heute im Süden und Südosten Marokkos weiträumig aufgeschlossen. Die Arbeit fasst die Ergebnisse dreier Studien zusammen, welche die Variabilität von Karbonat-Konturiten und die mit deren Ablagerung assoziierten Bedingungen – wie Hydrodynamik und Sedimentverfügbarkeit – dokumentieren. Darauf aufbauend werden Rückschlüsse auf steuernde paläoozeanographische Prozesse gezogen. Auf der Grundlage detaillierter Geländearbeiten werden zwei unterschiedliche Archive vom nordwestlichen Rand Gondwanas ausgewertet: (1) eine Unterdevon-Abfolge, aufgeschlossen in der Skoura-Region des südlichen Hohen Atlas, und (2) die Mittel- bis Oberdevon-Abfolge der Tafilalt-Plattform im östlichen Anti-Atlas. Die Unterdevon-Abfolge, im Fokus der ersten Studie dieser Arbeit, wurde auf dem distalen, durch Dehnungsprozesse mäßig ausgedünnten nordwestlichen Kontinentalrand Gondwanas (Meseta-Domain) abgelagert. Sie umfasst eine Konturit-Drift (im Folgenden bezeichnet als Tiliwine-Drift), die hauptsächlich aus bioklastischen Partikeln und Karbonat-Schlamm besteht. Während des Pragiums bis ins frühe Emsium kommt es zu einer sukzessiven Zunahme der durchschnittlichen Korngröße (coarsening-upward) und der Bankmächtigkeiten (thickening-upward), gefolgt von einer plötzlichen Verfeinerung (fining-upward) unterhalb der Grenze Unter-/Ober-Emsium. Die Untersuchung der Abfolge in vier Aufschlüssen, die ein etwa 75 km langes, west-ost-streichendes Transekt aufspannen, basiert unter anderem auf detaillierter Mikrofazies-Analyse, graphischer Dokumentation der Schichtenfolge im Gelände und drift-skaliger lithostratigraphischer Korrelation zwischen den Aufschlüssen. Dokumentiert wurden (1) vier Fazies-Assoziationen, mit bis zu 80 cm mächtigen vollständigen und unvollständigen bi-gradationalen Konturit-Sequenzen sowie (2) gut erhaltene Traktionsstrukturen von Strömungsrippeln und subaquatischen Dünen, die eine westwärts gerichtete Paläozirkulation anzeigen. Zudem (3) spiegelt der aus der Abfolge rekonstruierte zunehmende Einfluss der Bodenströmung vom Pragium bis ins Unter-Emsium, gefolgt von einer plötzlichen Reduktion der Strömung an der Grenze Unter-/Ober-Emsium, die plattentektonisch kontrollierte sukzessive Einengung der ozeanischen Passage zwischen den konvergierenden Landmassen von Laurussia und Gondwana wider, welche schließlich zur vorübergehenden Schließung der Meerenge (Amerikanische Pforte) und einer Unterbrechung der Paläozirkulation zwischen dem Rheischen Ozean und der Panthalassa vor etwa 400 Ma führte. Die Mittel- bis Oberdevon-Abfolge der Tafilalt-Plattform, im Fokus der zweiten Studie, repräsentiert den nördlichen Rand des ausgedehnten Epikontinentalmeeres im Nordwesten Gondwanas. Die Tafilalt-Plattform, zuvor als eine flache pelagische Plattform beschrieben, ist weltweit bekannt für ihre fossilreichen Cephalopoden-Kalke. Die Neubewertung des Ablagerungsmilieus dieser und assoziierter Sedimente führte zu einer Neuinterpretation der Plattform als Karbonat-Konturit-Terrasse (Tafilalt-Konturit-Terrasse), gelegen am Übergang vom Schelf zum Kontinentalhang, unterhalb der Sturmwellenbasis. Die untersuchte Abfolge (Eifelium bis Frasnium) ist kondensiert und reich an Schichtlücken. Die Sedimentakkumulation wurde kontrolliert und teils unterdrückt durch Bodenströmungen variierender Intensität. Fünf Fazies-Assoziationen spiegeln die Ablagerungsbedingungen wider, u.a. geprägt durch oxische Bodenströmungen geringer Strömungsgeschwindigkeit im Wechsel mit periodisch auftretenden, teils erosiven, anoxischen Bodenströmungen. Die dokumentierten Fazies indizieren eine komplexe Interaktion aus (1) Ablagerung aus der Suspension, (2) Transport und Ablagerung von Bodenfracht, (3) temporärem dynamischem Sediment-Bypass, ursächlich verbunden mit einer frühdiagenetischen Zementation des Meeresbodens und (4) strömungsindizierter Erosion und Umlagerung. Diese Prozesse wurden durch die vertikale Verlagerung einer Wassermassengrenze gesteuert. Die Studie demonstriert mit der Dokumentation eines breiten Spektrums karbonatischer Konturit-Sequenzen und der Sedimentarchitektur der Tafilalt-Konturit-Terrasse die beträchtliche Variabilität klein- bis großmaßstäblicher Konturit-Merkmale. Darüber hinaus bietet sie Einblicke in die vielfältigen hydrodynamischen Prozesse, die den Ablagerungsraum prägten. Die dritte Studie dieser Arbeit stützt sich auf die sedimentologische Analyse der vorangegangenen Studie und untersucht die Mittel- bis Oberdevon-Abfolge einer kleineren Drift im oberen Teil der Tafilalt-Konturit-Terrasse. Der Fokus dieser Studie liegt in der Rekonstruktion paläozeanografischer Prozesse, die das synchrone Auftreten Organik-reicher bioklastischer Konturite (organic-rich coquinas - ORCs) und globaler evolutionärer Ereignisse verknüpfen. Paläoströmungsdaten, abgeleitet aus primären Sedimentstrukturen innerhalb der Corg-reichen bioklastischen Konturite, liefern zusammen mit dreidimensionalen Rekonstruktionen, mittelskaliger morphosedimentärer Konturit-Merkmale und biostratigraphischen Daten Hinweise auf starke, nordwestwärts gerichtete, hangparallele Bodenströmungen. Diese Bodenströmungen hatten einen zweiphasigen Impact auf den Sedimentationsraum der Tafilalt-Konturit-Terrasse. Sie führten zunächst, bedingt durch Erosion und Sediment-Bypass, zu (1) weitreichenden biostratigraphischen Lücken, und anschließend (2) zur Ablagerung der ORCs aus der Schichtfracht. Zurückgeführt werden sie auf wiederholte Schelfwasserkaskaden (overflows), durch die dichtes, anoxisches Schelfwasser die Tafilalt-Konturit-Terrasse überströmte. Diese Resultate bestätigen die Bildung euxinischer Wassermassen durch starke Verdunstung und wiederkehrende anoxische Verhältnisse in der photischen Zone (top-down Mechanismus) des Epikontinentalmeers südlich und südöstlich der Tafilalt-Konturit-Terrasse, innerhalb der dortigen Intra-Schelfbecken (Reggane, Ahnet, Berkine und Ghadames). Meeresspiegelschwankungen infolge kurzzeitiger, klimatischer Wärmphasen (hot-house conditions) lösten wahrscheinlich den periodischen Überlauf und das Kaskadieren dieser anoxischen Wässer von den epikontinentalen Becken, über die TCT, in Richtung Ozean aus. Erstmals wird in dieser Studie ein Konturite-Archiv genutzt, um die paläozoischen Zirkulationsmuster zu entschlüsseln, welche die anoxischen Events des Devons maßgeblich beeinflusst, wenn nicht sogar verursacht haben, und letztlich in der Kellwasser-Krise an der Frasnium/Famennium-Grenze gipfelten. Diese Doktorarbeit unterstreicht die Bedeutung von Konturiten als Archive paläozeanografischer Prozesse und plattentektonischer Ereignisse. Basierend auf multiskaligen Analysen liefert sie Einblicke in die komplexe Dynamik von Bodenströmungen und deren Rolle bei der Erosion, dem Transport und der Ablagerung von Sedimenten. Sie unterstreicht die Bedeutung von Mikrofazies- und Paläoströmungsanalysen sowie die Relevanz großräumiger Kartierungen der Faziesvariabilität von Sedimenten, um eine Rekonstruktion paläozeanografischer Zirkulationsmuster und assoziierter Umweltveränderungen zu ermöglichen.

Global change is one of the major challenges our society faces in recent times and is becoming increasingly noticeable in all aspects of our lives. In the last ten years, reports about droughts in Europe increased, contrary to expected natural climate variations and are attributed as indicators of climate change. Droughts resulted in a severe decrease in water levels of lakes, rivers and reservoirs, posing socio-economic and environmental challenges. Climate scenarios by the Intergovernmental Panel on Climate Change (IPCC) project increasing temperatures, more frequent, longer and/or more intense heat waves and warm spells, and an increase in aridity with short-term droughts in the upcoming decades for Western and Central Europe. Some areas – such as Northeast Germany – are already affected by negative water balances and the lowering of lake and groundwater levels. Additionally to possible challenges in water availability, excess nutrients and heavy metals from industrial emissions, agricultural fertilisers and land use changes lead to declining water quality. In the past century, extensive eutrophication and environmental pollution have become major water quality issues in many freshwater bodies. Nonetheless, water and its availability in a sufficient quantity and quality are prerequisites for life and must be prioritised in future development. The European Union aims for a good status in all surface and groundwater bodies by 2027 regarding their ecological, chemical and quantitative status. However, a profound understanding of eutrophication, pollution sources, and water bodies' reference conditions – referring to pre-anthropogenic conditions – should be available for each system to apply integrated restoration strategies. Moreover, an in-depth understanding of long-term climate variability and its dynamics is indispensable to approach these climate change challenges and reliably predict water availability. During the past decades, numerous paleoenvironmental studies have been carried out on Northern German sediment archives, using mainly lacustrine sediments to reconstruct hydroclimatic variability, often inferring lake-level variations as key indicators. However, most studies were carried out in areas affected by more maritime or continental climate. Studies from the transition zone are rare. Only few existing studies offer high-resolution records and/or robust chronologies, which limits the understanding of past environmental changes significantly. Besides, the Northern German lowlands have been anthropogenically affected since at least the Neolithic (~5.6 ka cal BP) and, in particular, forest composition and density have recently been shown to have at least partially an impact on lake-level variations. However, a reliable distinction between climatic impacts and anthropogenic interferences is widely missing, which is a problem because many studies were conducted on rather small lacustrine systems in which expected anthropogenic signals are higher, and single events may overprint the climatic signals. These biases lead to an incoherent picture of the past hydroclimatic variability in Northern Germany during the Holocene. To overcome this situation, it is inevitable to identify a suitable sedimentary archive from the transition zone – preferably a large lacustrine system in which natural (supra-)regional paleoenvironmental signals are expected to be not overprinted by single events. Moreover, it is necessary to establish robust chronologies and apply high-resolution methods to infer past environmental changes in a high temporal resolution. Taken together, this could contribute to an enhanced understanding of past environmental and climatic changes in Northern Germany. This thesis consolidates the evidence for Schweriner See to act as a suitable sedimentary archive in Northern Germany for (supra-)regional climate reconstructions. Schweriner See is a large lowland lake in Northern Germany located within the transition zone from maritime to continental climate. In the first step, (paleo)lacustrine landforms, i.e. beach ridges, subaerial nearshore bar, and a silting-up sequence, are investigated along the north-eastern shoreline using a combined approach of sedimentology (e.g. grain size variations) and the relatively novel method of luminescence profiling offering relative age determinations to understand depositional processes and their chronological framework. Absolute age information is mainly inferred by OSL dating. Secondly, an important prerequisite to interpreting information obtained from lacustrine sediment archives is a thorough understanding of processes controlling sedimentation. Schweriner See is characterized by a complex morphometry, which influences in-lake processes, i.e. i) in-lake productivity, ii) carbonate precipitation and iii) wind- and wave-induced processes, resulting in a distinct spatial heterogeneity. This thesis shows that it is crucial first to understand sedimentary depositional processes and controlling mechanisms to i) select suitable coring location(s) and ii) reconstruct paleoenvironmental and hydroclimatic variations reliably. Based on bathymetric considerations and inferred in-lake processes, two main coring locations were identified to infer i) the anthropogenic impacts and ii) hydroclimatic variations. Short sediment records from the shallow water areas (< 15 m water depth) cover the most recent environmental history of Schweriner See. A well-dated sedimentary record (210Pb/137Cs and 14C dating) links distinct sedimentary and geochemical changes with historical events. Schweriner See was extensively affected by lake-wide eutrophication and contamination, closely related to sewage and population dynamics within the catchment. The water quality only improved after the German Reunification in 1990 CE when sewage was precluded from Schweriner See. Contamination trends at Schweriner See showed similar trends to different archives along the southern Baltic Sea, implying a common regional driving mechanism, e.g. environmental legalisation. A well-dated sediment record from the profundal zone (52 m water depth) allowed the reconstruction of large-scale atmospheric conditions during the past 3 ka cal BP by inferring winter temperature variability, the moisture source region and/or evaporative lake water enrichment, which resemble variations in the North Atlantic Oscillation (NAO). The NAO greatly influences the Central European climate, affecting, for example, surface air temperature, precipitation or storm tracks. During 3-2.8 ka and 2.1-0.8 ka cal BP, predominantly positive NAO conditions are reconstructed, which are characterized by warmer winter temperatures, moisture conditions bringing isotopically enriched precipitation from the southern/central North Atlantic to Northern Central Europe and/or warmer temperatures that may result in a higher evaporative isotopic lake water enrichment as a result of northwards displaced westerlies. Conversely, during 2.8-2.1 ka and 0.8-0.1 ka cal BP, results correspond to predominantly negative NAO phases influenced by southwards displaced westerlies. Frequent atmospheric blocking allows for the intrusion of northerly or easterly winds, resulting in colder winter temperatures, isotopically depleted precipitation from the Northern Atlantic and Arctic region and/or a lower evaporative lake water enrichment. In addition to these long-term changes in atmospheric conditions, short-term hydroclimatic variations have been reconstructed, mainly reflecting lake-level variations in conjunction with precipitation variability, with the proxy signal being additionally amplified by wind speed and wave motion. Comparisons with other archives support these results. So far, the paleoenvironmental reconstruction is limited to the Late Holocene, but initial dating results imply possible interferences until the Late Pleistocene. Therefore, future studies should focus on extending the profundal record from Schweriner See further back in time, providing a high-resolution record covering both the Holocene and possibly the Late Pleistocene.

Underground hard coal mining operations irreversibly disrupt the pre-existing mechanical equilibrium of the geological media. The employment of high-recovery methods modifies the stress field of the sedimentary sequence, generating movement and faulting of the rock layers above and below mined seams. These new fracture zones do affect the original conditions of the hydrogeological system by modifying flow pathways and increasing the permeability of the rock sequence. Moreover, the surface area of rock exposed to air and water is increased, conditioning the water-rock interaction. Despite this rather clear conceptualization, flow and reactive transport processes in fractured overburdens are rarely modeled simultaneously. Discrete setups that consider fractures and porous matrix require extensive characterization of both media, which is impractical for regional case studies. As a result, most post-mining models explicitly ignore fracture structures by employing the equivalent porous approach or even both media with lumped parameter models. However, omitting either medium represents a delicate simplification, considering that mining-related fractures control the rate and direction of water flow within moderately permeable but relatively highly porous rock sequences. In this dissertation, the specific contribution of fractured and matrix continua to the transient discharge and water quality of a post-mining coal zone is quantified and evaluated. For this purpose, dual and multiple interacting continua models are employed to simulate fluid flow and reactive mass transport in fractured and variable water-saturated rock sequences. The effectiveness of the models is evaluated by simulating the origin, generation and transport of acid mine drainage (i.e., water with elevated concentrations of hydrogen, iron, sulfate and chloride) within the shallow overburden of the Ibbenbüren Westfield. Compared to other coal districts in Germany, this area is strongly delimited by the local geology and topography, resulting in a well-defined hydrogeological system to test the models. Petrographic and chemical analyses performed on core samples from the area show the strong influence of mining-derived fractures on the water-rock interaction within the Carboniferous sequence. The presence of oxidized pyrite along with amorphous iron hydroxide phases in weathering fronts on both sides of the fractures demonstrates the exchange of solutes and gases between the fractured and the porous matrix media. Based on the previous evidence, the TOUGHREACT software is employed to characterize flow and reactive transport processes in the Westfield. However, each of the two processes is simulated at separate stages to have more control in the adjustment of sensitive parameters for which little information is available. For the flow component, a dual continuum model, with Richard’s equations is used to characterize the unsaturated water flow in both fractured and matrix media. Under this approach, the model adequately reproduces the bimodal flow behavior of the discharges measured in the mine drainage for the years 2008 and 2017. Simulation results show how the fractured continuum generates intense discharge events during the winter months while the rock matrix controls smooth discharge limbs in summer, when water is slowly released back to the fractures. With the flow component calibrated, the second part of the study incorporates the geochemical processes into the model based on actual data from the rock samples. Their simulation requires extending the two-continuum setup to a multiple continua model with five nested block strings: one for the fractures and four for the rock matrix. This further subdivision prevents under-representations of kinetic reactions with short equilibrium length scales and numerical instabilities due to lack of chemical and flow gradients. As a result, the new multiple continua model provides good agreement with respect to long- and short-term concentrations and discharge trends measured in the mine drainage. The flow of oxygen and meteoric water through the fractured continuum leads to a high and steady release of hydrogen, iron and sulfate ions derived from pyrite oxidation in the matrix continua closest to the fractures. Moreover, high chloride concentrations result from the mixing and gradual release of relatively immobile solutes in the matrix as they interact with percolating water in the fracture. Both findings are equally congruent with the reactive pyrite oxidation and iron hydroxide precipitation fronts identified in the fractured core samples. In the end, the multiple continua models, the simulation procedure and the results of the benchmark and sensitivity analysis scenarios developed for the Westfield pave the way for the application of the approach in other mining zones. The first candidate emerges in the Ibbenbüren Eastfield, where a coupled elemental-isotopic approach included in this thesis has confirmed that water-conducting fracture zones are primary elements for solute generation and transport in the first 300 meters of the overburden. In the latter case, calibration and verification of the models can be complemented with measurements of δ34S in sulfates and δ18O, δ2H, and Tritium in water.

Seas and oceans are essential for the global ecosystem. Entire societies, economies and countless livelihoods rely on their good environmental status. Yet, pressures on marine environments are increasing. An extensive assessment and monitoring of marine habitats is a vital precondition for understanding these systems and their sustainable conservation. Remote sensing methods can temporally accelerate the mapping, improve the spatial resolution and support the interpretation of large areas. Hydroacoustic becomes the method of choice for areas deeper than the coastal zone as optical signals are limited by strong attenuation in the water column. Apart from depth measurements for the creation of bathymetric charts, the recording of backscatter strength is useful for the characterization of the seafloor surface. The direct influence of the inhabiting benthic community on the backscattered signal is rarely considered, although it can be utilized for the detection of benthic life. Information about habitat-specific backscatter responses or a hydroacoustic remote sensing catalog for benthic habitats is missing so far. The multibeam echosounder (MBES) has the advantage of recording both, bathymetry and backscatter strength simultaneously with related incidence angle. Further, recent technological developments allow to change between frequencies. Angular range curves supported the quantification of backscatter strength of different frequencies. Acoustic data sets were complemented by ground truthing in form of sedimentological and biological samples as well as video profiles. Study areas were located offshore the island of Sylt in the North Sea as well as in vicinity to Oder Bank and close to the coast offshore Hohe Düne/Rostock, both in the Baltic Sea. Investigated habitats included sand areas inhabited by tubeworms, loose mussel clusters on top of sand areas, seagrass meadows, coarse sand and gravel areas, and a reef covered by mussels. Multifrequency backscatter maps, combining frequencies between 200 kHz and 700 kHz, illustrate small-scale features at the seafloor not visible in monofrequent maps. Key habitats showed a specific backscatter response, which can partly be related to macrobenthic flora and fauna. Data sets recorded with a (partly calibrated) MBES in three different month (May, August, October) revealed that backscatter strength can further detect spatial as well as temporal habitat dynamics. Alterations in the sediment composition at the seafloor surface of the ecologically valuable coarse sand and gravel areas were caused by seasonal changes in local hydrodynamics. A newly developed 3D seismic lander has the ability to support hydroacoustic remote sensing as an additional, non-destructive ground truthing method utilizing a high frequency of 130 kHz to image the shallow subsurface. Buried objects, e.g., stones, shells, fruit gummy worms, as well as sediment disturbances could be detected and visualized in a laboratory experiment. The 3D seismic lander is likely to improve the investigation of volume scatter contribution to backscatter strength and is potentially applicable for the imaging of bioturbation.

This thesis aims to investigate effects of anthropogenic environmental impact on the Richards Bay area. Located on the east coast of South Africa, Richards Bay Harbour evolved into the country’s premier bulk cargo port. The Associated change in land-use and industrial as well as agricultural pollution pose environmental, ecological and human health risks. Here, sedimentological and geochemical investigations focus on the port as final sink for environmental and industrial pollutants, such as metal concentrations, organochlorine pesticides and microplastics. The study is based on investigations of surface sediment samples from the water-sediment interface to identify spatial distribution patterns, as well as sediment cores to follow temporal changes. Endmember modelling of grainsize distributions, proved to be a viable parameter to distinguish different accumulation spaces and enabled the classification into six harbour sub-basins. Subsequent investigations on the content of microplastics, Polyethylene terephthalate (PET) and Low-density polyethylene (LDPE), showed that these different types of microplastics predominate in two different areas: PET appears to be directly tied to higher populated (tourism) beaches, while LDPE is deposited in low-current sub-basins. Increased metal concentrations link to activities at the bulk cargo berths, where especially Cr and Cu concentrations exceeded the local sediment guideline thresholds. In the areas of high metal concentrations, bioindicators (ostracods, foraminiferas, diatoms) also indicate increased shares of malformed specimens. Multiple recovered sediment cores recorded changes in recent export practices, indicating ceased Cu handling and increased Cr handling over the past decade. Noticing multiple possible influencing factors on elemental distributions, created by the surrounding geological and industrial impact, the usefulness of different normalisers (Al, Fe, Rb, Ti and silt fraction) for Cr, Cu, Co and Pb concentrations was compared and site specific baseline metal concentrations were defined. This identified Al and Rb to be effective normalisers in Richards Bay and Fe or Ti to be affected by local conditions. Data of organochlorine pesticide pollution was gathered in the area of Richards Bay, Goedertrouw Dam and Umlalazi River. The two dominant groups of contaminants detected are dichlorodiphenyltrichloroethanes (ΣDDT, 12 – 350 ng g-1), linked to the use of malaria vector control, and hexachlorocyclohexanes (ΣHCH 35 – 230 ng g-1), an agricultural insecticide. Both indicate recent entry and exceed sediment quality guideline limits, raising concern for local communities and estuarine environments. Seismic data was used to investigate the preindustrial evolution of the incised valley system and bayhead delta at Richards Bay Harbour. A stratigraphically supported development model was created. The thesis shows that harbour sediment is an important sink for inorganic and organic contaminants. Each investigation on environmental pollutants, such as metals, pesticides, microplastics or bioindicator analyses, indicates their deposition in distinct harbour sub-basins. Therefore, their effect can be spatially differentiated and related to plausible sources of pollution. Richards Bay thus represents a variously affected system along the South African coast, in which it is necessary to take environmental protection measures in terms of sustainable and environmentally friendly management.