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Using the first high-resolution geophysical data set collected from the uThukela Banks Marine Protected Area (MPA), we reveal a plethora of hitherto unknown or poorly resolved seabed features. In tandem with several remotely operated vehicle dives, we improve on the previous National Biodiversity Assessment map for the area and reveal a more complex picture of the seabed geology and geomorphology on which the MPA is predicated. The upper slope (-120 m and deeper) is dominated by small canyons, gullies and rills that occasionally extend to the shelf edge and form a series of slumps. Suspected cold-water corals were imaged on the interfluves of the Thukela Canyon. The mid to outer shelf (-60 to -100 m) is mostly rocky, and is composed of Pliocene-age siltstones for the most part. Aeolianite shorelines are found at depths of 60 m and 100 m, in which palaeo-lagoons and parabolic aeolian dune systems are also preserved. These features provide habitat for mesophotic corals and demersal fishes. Overlying and abutting hard rock substrates are unconsolidated sandy sediments that are mobilised by the inshore movement of the Agulhas Current. An inshore mud belt characterised by pockmarks associated with free gas expulsion is mapped for the first time. A well-developed palaeo-drainage pattern is also revealed, posing exciting new opportunities for the study of benthic communities associated with palaeo-estuaries and lagoons now exposed at the seabed. Several new habitats, both inside and out of the MPA boundaries, should form the basis for future research within the MPA, in addition to informing expansions of the MPA. Significance: • Using a newly collected geophysical data set, we provide an unprecedented glimpse into the newly proclaimed uThukela Banks Marine Protected Area. • We reveal a complexity of marine habitats hitherto unknown from previous biodiversity surveys. These habitats include areas of possible expansion given the recognition of keystone species that occur just outside the MPA limits. [ABSTRACT FROM AUTHOR]

Beachrocks are a common characteristic of tropical and subtropical coastlines. It is known that they have a substantial influence on beach morphodynamics and they are commonly utilised as indicators of palaeo‐sea levels. At the same time, facies variability in beachrocks is understudied and their effect on shoreline evolution is poorly understood. At Mission Rocks on the KwaZulu‐Natal coastline of South Africa a narrow beach with isolated sand patches occupies low points of an otherwise continuous 3 m thick, raised shore platform of sandy and gravelly beachrocks. These beachrocks are in the process of disintegrating into megagravel deposits through chemical and mechanical weathering in a wave‐dominated, high‐energy setting. The breakdown is potentially slowed by a contemporary, fast‐forming beachrock facies, that blankets the surface and fills fractures and potholes within the older platform. The accumulation and cementation of this recent beachrock is the focus of this study. The beachrock is dated by historical evidence to post‐World War II. Data from field observations, petrographic and geochemical methods reveal that the cementing agents of the beachrock were precipitated from marine water in a phreatic setting despite its position above the intertidal zone. Not only does this facies have implications for the interpretation of palaeo‐beachrock as a sea‐level indicator, it also raises further questions regarding modelling of coastal erosion of beaches associated with outcrops of beachrock. [ABSTRACT FROM AUTHOR]

Evidence for sea-level change during and around Marine Isotope Stage (MIS) 5e (ca. 125 ka) in southern Africa derives from a wide variety of geomorphic and sedimentological sea-level indicators, supported in the past 2 decades by absolute chronological control, particularly on littoral deposits, some of which have a quantifiable relationship to former sea level. In addition to these proxies, data provided by both terrestrial (dune sediments and archaeological remains) and marine (lagoonal and nearshore littoral sediments) limiting points provide broad constraints on sea level. Here, we review publications describing such data points. Using the framework of the World Atlas of Last Interglacial Shorelines, we insert in a standardized database (10.5281/zenodo.4459297, Cooper and Green, 2020) all the elements available to assess former palaeo-relative sea level (palaeo-RSL) and the chronological constraints associated with them (including uncertainties). Overall, we reviewed 71 studies, from which we extracted 39 sea-level indicators and 26 limiting points. As far as age attribution is concerned, early analysis of molluscs and whole-rock beachrock samples using U series allowed dating of several sea-level indicators during the 1980s, but the more widespread application of optically stimulated luminescence (OSL) dating since 2004 has yielded many more (and more accurate) sea-level indicators from several sites. This has helped resolve the nature and timing of MIS 5e shorelines and has the potential to further elucidate the apparent presence of two or more sea-level peaks at several South African sites during this interval. The standardized sea-level database presented in this paper is the first of its kind for this region. Future research should be directed to improve the stratigraphic description of last interglacial shorelines and to obtain better dating, high-accuracy elevation measurements with better palaeo-RSL interpretation. [ABSTRACT FROM AUTHOR]

Evidence for sea-level change during and around Marine Isotopic Stage 5e (ca. 125 ka) in southern Africa derives from a wide variety of geomorphic and sedimentological sea-level indicators, supported in the past 2 decades by absolute chronological control. In addition to these proxies, data provided by both terrestrial (dune sediments and archaeological remains) and marine (lagoonal and nearshore littoral sediments) limiting points provide broad constraints on sea level. Here, we review publications describing these data points. Using the framework of the World Atlas of Last Interglacial Shorelines, we insert in a standardized database all the elements needed to assess former paleo relative sea level, and the chronological constraints associated with them (including uncertainties). Overall, we reviewed 69 studies, from which we extracted 35 sea-level indicators and 25 limiting points. As far as age attribution is concerned, early dating of molluscs and whole-rock beachrock samples using U-Series allowed ating of several sea-level indicators during the 1980s but the more widespread application of Optically Stimulated Luminescence dating since 2004 has yielded many more (and more accurate) dates from several sites. This has helped resolve the nature and timing of MIS5e shorelines and has the potential to further elucidate the apparent presence of two or more sea-level peaks at several South African sites during this interval. The standardized sea-level database presented in this paper is the first of its kind for this region. Future research should be directed to improve the stratigraphic description of LIG shorelines and to obtain better dating, high-accuracy elevation measurements with better palaeo-RSL interpretation. [ABSTRACT FROM AUTHOR]

The morphodynamics and structure of barriers with persistent tidal inlets have been well studied. In contrast the stratigraphy and functioning of barrier systems with ephemeral inlets is poorly understood. This article examines the barrier‐inlet systems of two intermittently closed open lagoons or temporarily open closed estuaries on the east coast of South Africa. Multiple geophysical surveys using ground‐penetrating radar (GPR) were correlated with exposed sections of the barrier where inlet formation revealed the internal stratigraphy. Stratigraphic observations were placed in the context of the contemporary wave dynamics and mesoscale geomorphic evolution. The integrated databases reveal an absence of migrating channel features. Instead the stratigraphy is dominated by landward dipping sheets of alternating high‐ and low‐amplitude reflectors. These correlate with gravel, shell debris and heavy mineral‐lined beds formed by overwash processes. Where ephemeral inlet structures are preserved in the stratigraphy, their fills comprise aggrading, high‐amplitude reflectors, linked to washover infilling of the inlet mouth. Multiple small channels in the more distal portions of the barrier in georadar stratigraphy are related to channelized washover flow. These barriers often breach during high swell and are subsequently sealed during fairweather wave conditions. Time series analysis of waves and satellite imagery shows a link between storms from the south and breach events. This is consistent with the truncations in subsurface images and inferred barrier lowering by overwash channelling. These barriers experience quasi‐stable oscillations in their landward and seaward shore position, punctuated by periods of barrier rollover associated with the most intense storms. As overwash is responsible in part for both the constructive and destructive phases of the barrier, these barriers have low preservation potential. Persistent rollover driven by overwashing will terminate once accommodation space is eliminated and the barriers are eroded by storm activity. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Terrestrial signals in marine sediment archives are often used for paleoclimatic reconstructions. It is therefore important to know the origin of the different terrestrial sedimentary components. The proximity to a river mouth is often the key location to determine the source. Especially in regions with strong ocean currents, such an assumption might, however, lead to considerable misinterpretations. To investigate the source of various terrigenous sediment fractions in southeastern Africa, a region with strong sediment redistribution, we have performed an extensive comparison between terrestrial material (pollen, plant lipids, detrital modes, and heavy minerals as well as bulk inorganic geochemical composition) from potential source regions and the same components in the adjacent coastal and continental shelf sediments. Onshore the proxy‐indicators reflect small‐scale diversity in sampling locations and associated environments (riverbank sediments, flood deposits, suspension loads, and soils). Nevertheless, the overall trends reflect significant environmental gradients along a SW to NE transect. We note a general comparability of the studied parameters between the continental and marine sediments regardless of their specific differences in transport and depositional characteristics. We propose that the influence of the Agulhas Current affects sediment deposition and distribution only seaward of the midshelf and that pockets of sediment remain preserved in the lee of coastal protrusions where they are protected from erosion. This study provides the essential prerequisite to allow the attribution of temporal variations of compositional changes in marine sediment cores to environmental changes in southeastern Africa. [ABSTRACT FROM AUTHOR]

This study examines a Holocene-aged submerged shoreline, Limestone Reef, located in the shallow subtidal zone of South Africa's east coast. It comprises an elongate, coast-oblique, slab-like outcrop of beachrock situated above the contemporary fair-weather wave base. It is currently undergoing mechanical disintegration. Its unique and rare preservation in a high-energy setting affords an opportunity to examine the mechanical processes occurring during wave ravinement associated with rising sea level. The submerged shoreline and the adjacent shoreface were examined using high-resolution seismic reflection, side-scan sonar and shallow-water multibeam echosounding techniques. Limestone Reef rests on top of unconsolidated Holocene deposits. The structure's surface is characterised by reef-perpendicular gullies with rubble derived from the slab fringing its seaward edge. Limestone Reef slopes gently seawards and has a steep landward-facing edge where gullies are most prominently developed. Teardrop-shaped rippled scour depressions, marked by high backscatter, are located seawards of the submerged shoreline. These elongate in a seaward direction and are filled with bioclastic gravels and residual rubble from Limestone Reef. The gullies in the upstanding structure are indicative of wave plucking and abrasion of the shoreline. The material exposed by the rippled scour depressions is identical to that comprising the postglacial ravinement surface identified in the offshore stratigraphy. These deposits are considered to represent the contemporary, actively forming wave ravinement surface. The results suggest that wave ravinement of submerged shorelines is a discontinuous process dominated by the seaward entrainment of material from its landward edge controlled by high-energy drawback during storm surges. The ravinement process appears to operate at the seasonal scale and averages out over the long-term millennial scale for the continuous surface. [ABSTRACT FROM AUTHOR]

On the SE African shelf, a submerged shoreline at a depth of 60 m is examined and its attributes compared between two shelf sectors with different morphologies, yet similar energy regimes. The aim is to assess the controls of antecedent conditioning on shoreline development and later preservation from transgressive ravinement. Using a combination of multibeam bathymetry and single-channel seismic profiles, the stratigraphy and morphology of the shoreline is investigated. Low-gradient bedrock examples reveal several distinctive seismic facies, including onlapping chaotic reflector packages which are interpreted as calcarenite rubble fields. These palaeo-shorelines possess planform equilibrium morphologies, including parabolic dunes and blowout forms along with relict shore platforms. They are strongly associated with incised valleys of last glacial maximum age which underlie the shoreline locations; these provide wide, back -barrier accommodation space during transgression. In contrast, palaeo-shorelines on the steeper-gradient shelf have a simpler stratigraphic arrangement. They are not as well preserved, are generally covered by thick drapes of sediment, and lack the elaborate planform morphologies of their lower-shelf gradient equivalents. Isolated incised valleys and the steep bedrock gradient limit accommodation space. The comparison indicates that antecedent bedrock slope and available accommodation are amongst the dominant controls on overstepping, and thus potential preservation, of palaeo-shorelines on the shelf. Lower-gradient shelves not only promote rapid shoreline translation but, together with wide, sandy back -barrier accommodation, also foster larger barrier volumes. In suitable climates such as in the Mediterranean and other sub-tropical areas, the ensuing shoreline stability promotes rapid and effective cementation of the barrier. In comparison, steep bedrock profiles with limited back -barrier accommodation have much lower preservation potential. Transgressive ravinement is more focussed on steep slopes, effectively removing more material during the ravinement process. The more dynamic environment may also reduce the effectiveness of diagenesis. The potential of beachrock and aeolianite palaeo-shorelines as submerged sea-level indicators may be optimal in low-gradient settings in Mediterranean to subtropical environments. [ABSTRACT FROM AUTHOR]

The seismic stratigraphy, architecture and evolution of a large subtropical embayment, Maputo Bay, Southern Mozambique is described. Nine seismic units are documented; and show repeated phases of incised valley formation and transgressive infilling. Trangressive infilling alternates between the classic wave-dominated transgressive succession of fluvial and central estuarine bay deposits and the filling by intertidal flat and tidal bedforms developed during stages of inlet restriction and shallowing associated with barrier growth at stillstand intervals. Imprinted on the succession are several key facets of subtropical stratigraphy, hurricane-generated erosional surfaces and beachrock horizons. The upper stratigraphy comprises the highstand bayhead delta, a prograding feature constructed by several flood events. In comparison with literature from other similar systems such as lagoons, coastal lakes and estuaries, a generic three stage stratigraphic model of large marine embayments is proposed that includes incision during glaciations; transgressive infilling during deglaciations; and shallowing during the stillstand episodes of the recent deglaciation. [ABSTRACT FROM AUTHOR]

Selective development and preservation of major shoreline complexes on the continental shelf provide geomorphic evidence in support of alternating periods of Holocene sea-level stillstand and rapid rise during meltwater pulses. On a tectonically stable far-field setting (the southeast African shelf), regionally developed, well-preserved shoreline complexes occur at ~-100 m and ~-60 m within an overall shelf sequence dominated by transgressive ravinement (non-preservation of shorelines). The development of geomorphically mature submerged shorelines with equilibrium forms is attributed to extended periods of sea-level stability, and their preservation is the result of early cementation followed by very rapid sea-level rise (several centimeters per year) that caused overstepping. Meltwater Pulses 1A and 1B are recorded in the shelf stratigraphy and geomorphology. Setting aside local influences of topography and sediment supply, we hypothesize that shelf stratigraphies should preferentially preserve shorelines at water depths associated with the stillstands or slowstands immediately preceding meltwater pulses. A reappraisal of shelf stratigraphy and geomorphology, in particular the preservation potential of former shorelines, is required in the light of contemporary understanding of postglacial sea-level history. [ABSTRACT FROM AUTHOR]

Abstract: The late Holocene evolution of the Durban Bight shoreface is documented on the basis of core, seismic and micropalaeontological data. From a sedimentological perspective the shoreface comprises three fining-upward packages resting on either granule or pebble layers with well-defined erosional bases. The best developed of these is a lowermost pebble conglomerate that has been tied to a regionally developed erosion surface (g). The surfaces are interpreted as having formed on the lower shoreface during sediment exchange with the upper shoreface via storm-driven erosion. The succession is capped by a monotonous series of small sandy climbing bedforms, terminating in a thin, mudball-rich layer. The mudballs are the product of a large-scale fluvial flood that occurred in 1987. From a palaeontological perspective, the shoreface shows fluctuations in nutrient supply and temperature, identified by the relative abundance of F. profunda in terms of the high small placolith to lower photic species ratios, in addition to the changing bridge angle of Gephyrocapsa sp. Where storm-event layers are recognised, corresponding peaks in sea surface temperature (marked by high-bridge Gephyrocapsa assemblages) and low nutrient contents (low relative abundances of F. profunda) occur. Periods between storm events are characterized by cooler sea surface temperatures and increased nutrient contents. The controls on such fluctuations are the presence of the warm, oligotrophic Agulhas Current that occasionally meanders and impinges on the shelf; the local coastal upwelling triggered when the current migrates offshore; and the relatively lesser influences of the fringing fluvial sources during flooding. We consider that the event layers recorded in the shoreface succession are persistent stratigraphic features formed at times of increased storminess associated with the inshore meandering of the Agulhas Current. Where significant exchange of sediment occurs in the offshore as in the present case, this sediment is lost from the system and the shoreface recovery is stunted. [Copyright &y& Elsevier]

Purpose |!|#8211; The purpose of this study is to explore the causal link between procurement route and ongoing buyer-supplier relationship. Design/methodology/approach |!|#8211; The research draws on literature in the areas of: facilities management (FM) outsourcing; purchasing and supply chain strategy; and collaborative business relationship management. The research methodology is qualitative, and comprised semi-structured interviews with buyers and suppliers of FM services. Findings |!|#8211; Findings suggest that in general clients are seeking more collaborative relationships and this may determine a more relational procurement process. Some organisations appear more practiced than others in defining the level of collaboration and business benefits sought. Results support the view that a relational procurement process provides greater clarity of service requirements and facilitates cultural alignment between the buyer and supplier. However, additional time, effort, and cost are incurred, and concerns arise regarding the maturity of the supplier-market and the sincerity of client intentions to collaborate. Practical implications |!|#8211; A major practical implication is that facilities managers should recognise the importance of determining relationship objectives and the benefits sought within the context of FM procurement activity and select a purchasing route which supports the achievement of those objectives. Originality/value |!|#8211; Originality exists in the qualitative approach used to inquire into the causality between relationships and procurement routes. The study offers potential value to both buyers and suppliers of FM services through describing the attributes of a successful collaborative relationship and how they link to a given procurement process, and identifying the potential risks and rewards involved. [ABSTRACT FROM AUTHOR]

Ecological data on soil living amphibians and reptiles are largely lacking. Specialised methods relying on substrate excavation are required to adequately quantify fossorial herpetofaunal densities as surveying techniques which rely on surface movement (e.g. pitfall or funnel trap surveys) are biased against soil-living species which infrequently move over the soil surface. As part of a larger study, we quantified baseline densities for fossorial herpetofauna in grassland at Sileza Nature Reserve and in savanna at Tembe Elephant Park. All sites were underlain by aeolian sand. Grassland surveys were conducted at two adjoining sites, one during summer, and one in winter while both savanna sites were only surveyed during winter. Quadrats of 4 m2 (2 m x 2 m) were excavated to a mean depth of 0.25 m (volume of 1 m3) as most species of fossorial herpetofauna are considered to live at shallow soil depths. The excavated substrate was momentarily stored in 20 litre buckets before being sifted through a 2 mm x 2 mm (4 mm2) metal mesh, exposing soil living reptiles and amphibians. Grassland fossorial herpetofaunal densities were marginally lower during winter (0.56 individuals.m-2) compared to the summer (0.67 individuals.m-2) survey. Grassland species richness consisted of a single amphibian, Breviceps mossambicus, as well as five reptile species. Although amphibian species richness was considerably lower in grassland compared to reptiles, densities were higher especially during summer. Inter-seasonal demographic variability was observed in the grassland amphibian population with higher numbers of juveniles present during the summer. Herpetofaunal fossorial densities at savanna sites were on average more than four times lower (0.11 and 0.14 individuals.m-2 respectively) compared to grassland. Once again, the only amphibian present was B. mossambicus, but in much lower densities (0.01 and 0.02 individuals.m-2). It is hoped that the outcomes of this study will contribute to a better ecological understanding of soil megafauna in grassland and savanna ecosystems. [ABSTRACT FROM AUTHOR]

RECENT OBSERVATIONS MADE FROM THE submersible Jago have shed new light on palaeo-sea levels found off the continental margins of southeastern Africa. The discovery of deep-water caves within the northern KwaZulu-Natal submarine canyon system, and their corresponding intertidal erosional features, indicates three deeper than present sea levels at depths of 106 m, 124 m and 130 m. A clast-supported, cobble conglomerate is associated with caves of 124 m depth. This is interpreted as a beach deposit that formed during the Last Glacial Maximum (LGM) at 18 BP. This is the first evidence of the LGM for the east coast, and suggests tectonic stability throughout southern Africa since that time. [ABSTRACT FROM AUTHOR]