Durban Harbour Research Articles

An Exploration of Police Corruption at Durban Harbour Port of Entry in South Africa

This study delves into the pervasive issue of police corruption within a critical context of the Durban Harbour port of entry in South Africa. Police corruption poses a significant challenge to the integrity of law enforcement functioning of ports. This research highlights the role of inadequate training, resource constraints, bureaucratic inefficiencies, and lack of oversight as a significant contributing factor. It emphasises the necessity of enhancing organisational accountability, improving training programmes, and fostering a culture of ethical conduct to mitigate corruption. Lastly, this article recommends that addressing police corruption at the Durban Harbour port of entry demands a holistic and interdisciplinary approach involving law enforcement agencies, government bodies, civil society, and the private sector. The insights gained from this investigation can inform targeted interventions and policy reforms to fortify the integrity of law enforcement and enhance the security and efficiency of harbour port operations.

Reflective memories: The Indian diaspora who call South Africa home

Durban, a coastal city in KwaZulu-Natal (one of the nine provinces in South Africa) boasts the Durban Harbour. One hundred and sixty-two years ago, this harbour was referred to as the Port of Natal. Between the year’s of 1860 and 1911, 152 184 indentured Indian labourers entered the British owned Colony of Natal through this port. Even though indentureship was officially abolished in Natal on 21 July 1911, the hardships and challenges endured by Indian nationals in Natal continued. This article shines a spotlight on the period 1895–1960 through the theoretical prism of indentureship by focusing on the reflective memories of the respondent, Mr J.S. Singh, a nonagenarian. Using oral history methodology, face-to-face interviews were held with the respondent. His reflective memories brought alive the reality of life experiences in Natal between 1895 and 1960. He shared the journey of his Indian born paternal grandmother, Mrs Takurine Mahesh Singh who constitutes the cohort that left their country of birth as Indian nationals but subsequently created the Indian diaspora in Natal, where their descendants now call South Africa their home.Contribution: The content of this article is not simply described but also briefly reflected upon and explored as certain issues may be of interest to new, emerging and established oral historians. Furthermore, audio and video recordings of the interviews, which clearly illustrate oral history as the methodology as applied in this research, are available for academic, education and research purposes.

Time Integrated Metal Accumulation on Pellets in an Industrial Harbour “Durban Harbour”

Once in the environment, preproduction plastic polymers between 2–5 mm in size, also known as pellets, can cause physical harm to animals that mistake them for food as they have been reported to accumulate toxic substances, including on their surface. However, the rate of metal enrichment on pellets is not well investigated. In October 2018, Durban experienced a storm that resulted in ±2000 tons of polyethylene pellets being spilt into Durban Harbour, which caused environmental pollution concerns. This event provided a unique opportunity to study metal accumulation on pellets. Pellets were collected at one-month intervals for 6 months following the spill from October 2017 to March 2018, and metal concentrations were compared to concentrations found on pellets collected before the spill. The pellets were digested using a mixture of concentrated nitric acid (55%) and sulphuric acid (60%) at a ratio of 3:1 and analysed for numerous trace metals (Al, As, Pb, Cd, Cr, Fe, Cu, Mn, Ni, and Zn) using the Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Pellets collected in Durban Harbour prior to the spill in a related study (unpublished data) showed higher metal accumulation; however, there was no evident linear increase in metal concentration in pellets over time. ANOVA showed no significant difference for all metals (p > 0.05) in metal concentration between months; however, there was a significant difference between aged and newly introduced pellets.

Nurdle drifters as indicators of egg and early-stage larval fish dispersion and transport on the south-east coast of South Africa

There is considerable uncertainty about fish population connectivity and the trajectory for larval transport following adult spawning migrations from temperate to subtropical oceanic waters off the south and east coast of South Africa. In particular, the role of the Agulhas Current and local wind drift has not been fully elucidated as drivers for connecting coastal and offshore waters, and the results of a previous study that modelled the movements of plastic nurdles following a spill in Durban Harbour are used to infer dispersal and transport. Planktonic fish eggs and early stage larvae are passive and behave in a similar way to nurdles, and the rapid movement of the nurdles provided a unique opportunity to track coastal dispersal trajectories and provide insights into population connectivity in some migratory fish species. Under the variable wind conditions typical along the coast, the nurdles tended to remain localised but when winds blew consistently for a few days in one direction, the nurdles drifted from localised surrogate spawning areas and moved via Agulhas Current connectivity and onshore wind assistance to distal coastal locations hundreds of kilometres away. The rapid and extensive dispersal of nurdles served as a valuable surrogate for understanding dispersal dynamics of planktonic organisms in the surface layer of the ocean which has important implications for genetic dispersal in fishes.

Comparative analysis of trace metal levels in the crab Dotilla fenestrata, sediments and water in Durban Bay harbour, Richards Bay harbour and Mlalazi estuary, Kwazulu-Natal, South Africa

Durban Bay and Richards Bay Harbours are the largest and most economically active shipping harbours in South Africa supporting a diversity of ecosystems and biota of ecological importance. This study assessed and compared levels of metals in selected tissues of the sand bubbler crab (Dotilla fenestrata), water and sediments from anthropogenically impacted Durban and Richards Bay Harbours with those of Mlalazi estuary, a considered pristine site due to its sheltered catchments. Metal concentrations (Cd, Cu, Pb and Zn) were investigated using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Metals concentrations in crab tissues were as follows; exoskeleton > gill > digestive gland, metal concentrations in tissues followed the order Cu > Zn > Pb > Cd. Metal levels in crabs from Durban Harbour (Cd 0.42, Cu 83.8, Pb 2.43and Zn 6.4 μg/g) were significantly higher than Richards Bay (Cd 0.22, Cu 27.7, Pb 1.23 and Zn 9.54 μg/g) and Mlalazi estuary (Cd 0.17, Cu 18.7, Pb 3.53 and Zn 6.91 μg/g). Metal levels in sediments followed the order Zn > Cu > Pb > Cd. Mlalazi had significantly elevated metal levels in sediment (Cd 6.83, Cu 35.63, Pb 33.43 and Zn 56.27 μg/g) compared to Durban Harbour (Cd 2.73, Cu 16.07, Pb 12.20 and Zn 38.70 μg/g) and Richards Bay (Cd 3.10, Cu 16.00, Pb 11.43 and Zn 26.07 μg/g). Metal concentrations in water were Cu > Zn > Pb > Cd save Mlalazi estuary with significantly higher Zn levels. Mlalazi estuary, the considered pristine site had significantly elevated metal levels in the sediments and water compared with the impacted sites; however, had significantly lower metal levels in the crabs’ tissues due to lower metal bioavailability. Factors such as high natural metal concentrations, metal speciation, sediment grain and organic matter content could possibly account for high metal concentrations without corresponding bioaccumulation and magnification in crabs from Mlalazi estuary.

Prioritising potential incursions for contingency planning: pathways, species, and sites in Durban (eThekwini), South Africa as an example

Increased trade and travel have resulted in an increasing rate of introduction of biological organisms to new regions. Urban environments, such as cities, are hubs for human activities facilitating the introduction of alien species. Additionally, cities are susceptible to invading organisms as a result of the highly altered and transformed nature of these environments. Despite best efforts at prevention, new incursions of alien species will occur; therefore, prioritising incursion response efforts is essential. This study explores these ideas to identify priorities for strategic prevention planning in a South African city, Durban (eThekwini), by combining data from alien species watch lists, environmental criteria, and the pathways which facilitate the introduction of alien species in the city. Three species (with known adverse impacts elsewhere in the world) were identified as highly likely to be introduced and established in Durban (Alternantheraphiloxeroides,LithobatescatesbeianusandSolenopsisinvicta). These species are most likely to enter at either the Durban Harbour; pet and aquarium stores; or plant nurseries and garden centres – therefore active surveillance should target these sites as well as adjacent major river systems and infrastructure. We suggest that the integrated approach (species, pathways, and sites) demonstrated in this study will help prioritise resources to detect the most likely and damaging future incursions of alien species.

Nurdle drifters around South Africa as indicators of ocean structures and dispersion

Dispersion processes in the ocean typically involve wind, ocean currents and waves. All these factors were included in an analysis to model nurdle dispersion from an accidental spill in Durban Harbour, South Africa, in October 2017. Nurdle sightings on beaches by members of the public are used as indicators of the dispersion which extended over 2000 km of the South African coastline in a period of 8 weeks. Using known oceanographic current structures, satellite imagery, wave data and surface wind drift values of between 5% and 8% of wind speed, good agreement was found between the modelled dispersion and nurdle sightings. In particular, it was found that nurdles remained in specific sections of the coast for long periods, and that sporadic wind events were required to move them into new coastal areas. Such results may also contribute to understanding the dispersal behaviours and strategies adopted by larval stages of marine organisms, particularly fishes, that have pelagic larval durations that extend over weeks to months. The event was recognised as a major pollution incident rivalling other nurdle spillages reported worldwide, and extensive efforts were made to collect the nurdles, particularly along the northern KwaZulu-Natal coast. However, 9 months later, less than 20% had been recovered. The results emphasise the connectivity of different ocean regions, and in particular that pollution of the ocean is not a localised activity. Matter discharged at one point will disperse over a wide area – in this case, significantly further afield than the area of recovery operations.
 Significance: 
 
 Wind drift in the upper metre or two of the ocean has been notoriously difficult to quantify, and the spread of nurdles along the South African coastline can only be explained by using drift percentages two or three times the generally accepted value of 3% or less. Nonetheless, it is important to realise that there are substantial differences in dispersion rates between the upper few centimetres of the ocean and that even a metre or two deeper.
 The rapid manner in which nurdles, and other microplastics, can be dispersed is important in terms of understanding the spread of this form of pollution in the world’s oceans. The results also confirm the important role that wind can play in the movement of eggs, larvae and invertebrates and the significance of vertical migrations in and out of the surface layers.

Do microplastic loads reflect the population demographics along the southern African coastline?

Plastic pollution is a major anthropogenic contaminant effecting the marine environment and is often associated with high human population densities and industrial activities. The microplastic (63 to 5000μm) burden of beach sediment and surf-zone water was investigated at selected sites along the entire length of the South African coastline. It was predicted that samples collected in areas of high population density, would contain a higher microplastic burden than those along coasts that demonstrate very low population densities. With the exception of water column microplastics within Richard's Bay Harbour (413.3±77.53particles·m−3) and Durban Harbour (1200±133.2particles·m−3), there were no significant spatial differences in microplastic loads. This supports the theory that harbours act as a source of microplastics for the surrounding marine environment. Additionally, the absence of any spatial variation highlights the possible long range distribution of microplastic pollutants by large scale ocean currents.

Erratum to: Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour, South Africa

The uMhlatuzana, uMbilo and aManzimnyama river catchments located on the eastern seaboard of the KwaZulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only natural freshwater inflows to the Bayhead Canal portion of the Durban Harbour. In this study, seasonal discharges and physico–chemical water properties were used to quantitatively determine the material mass transport capacity of the river systems on the basis of hydrographic inputs and chemical loading from the surrounding land use sectors. The mass transport of the total dissolved solids (TDS), ammonia (NH4), phosphorous (P), aluminum (Al), calcium (Ca), copper (Cu), chromium (Cr), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), nickel (Ni), lead (Pb), sulphur (S) and vanadium (V) was determined for each river. Results indicated that land use, seasonality and river flow were significant determinants for the material loading in the rivers and the receiving port waters. The spatio-temporal distribution patterns of chemical fluxes indicated that industrial activity associated with the aManzimnyama canal contributed the most, with regards to TDS, NH4, Ca, K, Mg, Na, S and V, loading in both wet and dry seasons, as well as Al, Cu, Hg and Pb during the dry season. Similarly, industrial activity associated with the uMbilo/uMhlatuzana Canal at the lower reaches accounted for the highest P, Al, Cu and Pb fluxes in the wet season alone. Fluxes of these parameters are used to explain the observed elemental concentrations and patterns of the receiving port waters of the Bayhead Canal.

The invasive Asian green mussel Perna viridis in South Africa: all that is green is not viridis

The Asian green mussel Perna viridis is an invasive Indo-Pacific species recently reported from South African harbours. To verify the invasion, a phylogenetic (and morphological) analysis of green-shelled mussels (n = 39), found in six South African harbours, was conducted using the mitochondrial cytochrome c oxidase subunit I gene (COI). Estimates of genetic distances using the neighbour-joining analysis identified P. viridis only from Durban Harbour. All other green mussels were more than 3.2% divergent from P. viridis and were identified as green-shelled variants of indigenous P. perna. The only reliable morphological differences distinguishing the two species were the poorly developed mantle papillae and the wavy pallial line in P. viridis. The confirmed occurrence of P. viridis in a South African harbour suggests that there is a possible threat of the species becoming established and then spreading onto the open coast and competing with indigenous P. perna.

Plastic ingestion by estuarine mullet Mugil cephalus (Mugilidae) in an urban harbour, KwaZulu-Natal, South Africa

Coastal urban environments have high plastic pollution levels, and hence interactions between plastic debris and marine life are frequent. We report on plastic ingestion by mullet Mugil cephalus in Durban Harbour, KwaZulu-Natal, South Africa. Of 70 mullet (13.0–19.5 cm total length), 73% had plastic particles in their guts, with a mean of 3.8 particles per fish (SD 4.7). Plastic ingestion showed no relation to digestive tract content or fish length. White and clear plastic fibres were ingested most commonly. This urban population of M. cephalus had a higher incidence of plastic ingestion than has been reported in studies on fish from other coastal areas or the oceanic environment.

Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour, South Africa

Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour, South Africa

Oceanic Mobility and Settler-Colonial Power: Policing the Global Maritime Labour Force in Durban Harbour C. 1890–1910

Recent scholarship on seafarers in the late nineteenth and early twentieth century has tended to emphasise the mobility and diverse geographical origins of the global steamship workforce. This article, while sharing that perspective, cautions that a more nuanced view is called for, which also recognises the limits of their mobility. In doing so, it suggests, more broadly, that the period before the First World War cannot be thought of simply as an ‘Age of Acceleration’, but also needs to be seen as a period in which new kinds of limitation to mobility emerged. In the British colonial port of Durban, although there was in this period a vast increase in shipping activity, seamen were subject to an intense regime of restriction. An immigration bureaucracy initially created to exclude Indian immigrants, also shut out sailors of all nationalities and races. A particular precipitant of this policy was the hostility of Natal officials to the crews of ‘cattleboats’, ships bringing livestock to southern Africa from the Mediterranean, Argentina, Australia, the US and elsewhere. Across the globe, immigration controls in this period were in general less intense than they became after 1914, but in some places, such as Durban, new forms of limitation on mobility were being tried out. The article also highlights the vast worldwide system of labour documentation operated by the British merchant marine through Shipping Offices and Consuls in almost every significant port. Mobility in the British Empire was radically differentiated, with numerous centres of power making their own claims to control movement.

Spatiotemporal characterization of water chemistry and pollution sources of the Umhlatuzana, Umbilo and Amanzimnyama River catchments of Durban, KwaZulu-Natal, South Africa

The physical, chemical and microbiological properties of three freshwater systems contributing inflows to the Bayhead Canal of the Durban Harbour: the Umhlatuzana and Umbilo Rivers, and the Amanzimnyama Canal of KwaZulu-Natal, South Africa are presented. Parameters targeted for analysis collectively included pH, total dissolved solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, conductivity, ammonium ions, phosphorous, sodium ions, sulphur, copper, calcium, magnesium, chromium, aluminium, nickel, lead, vanadium, mercury, potassium ions, Escherichiacoli and total coliforms. These parameters were analyzed seasonally during the wet and dry seasons in relation to land use change for spatial characterization. Comparisons with relevant South African Water Quality Guidelines for freshwater systems showed that pollution associated with catchment activities was the main factor governing water quality, with nutrient concentrations that frequently exceeded prescribed standards and often rendered the system hypertrophic. In addition, the sanitary state of the rivers across all land use types was shown to be contaminated and polluted. This study also attempted to determine spatiotemporal (dis)similarity in the water quality of sample sites through Principal Components Analysis (PCA) with varimax rotation. Results show that although these systems were separated on the basis of water quality (both spatially and temporally), there were generally no apparent trends in water quality based on specific land use patterns which linked sites across different catchments. In the wet season, a few exceptions were noted for residential sites across the Umbilo and Umhlatuzana catchments and industrial sites across the Amanzimnyama catchment which showed spatial similarity. Finally, the study examined the impacts of the three freshwater systems on the water quality of the Bayhead Canal of the Durban Harbour, and identified the Amanzimnyama Canal as the most influential on heavy metal and microbiological contamination near the confluence.

Spatial and temporal variations in incised valley systems from the Durban continental shelf, KwaZulu-Natal, South Africa

Abstract The evolution of several incised valley systems from the KwaZulu-Natal shelf is compared over time. These represent the shelf extension of the collective Durban Harbour drainage system, and the Mgeni, Mhlanga, and Mdloti Rivers. Two main ages of incision are apparent; early Santonian (Cretaceous), and late Pleistocene/Holocene. The early valleys formed by tectonic controls, namely phases of higher frequency base level fall superimposed on lower frequency, higher order transgression. The results are complex networks of stacked compound valleys that have been exploited by some of the younger networks formed by glacio-eustatic fall prior to the last glacial maximum (LGM) of ~ 18 Ka BP. The valley fills have evolved from high energy basal fluvial deposits, low-energy central basin fines, mixed-energy estuarine mouth plug deposits, clay-rich flood deposits through capping sandy shoreface deposits. The earliest fills are dominated by central basin deposits and were underfilled as a result of low gradient and limited sediment supply. The more recent late Pleistocene/Holocene fills have significantly thicker fluvial deposits as a result of increased gradient and stream competence during the later stages of valley and shelf evolution. The youngest valleys show a situation of differential evolution along the valley length due to varying rates of sea level rise in the Holocene. Initial rapid sea level rise caused drowning and overstepping of the outer segment of the incised valley, whereas slower rates of sea level rise in the late Holocene caused shoreface ravinement of the inner-mid segments of the valley. This differential exposure to accommodation has resulted in a sedimentological partitioning between tide-dominated facies in the outer valley segment and river-dominated facies in the inner segment (cf. Cooper, 2001 ).

Isolation of a phenol-utilizing marine bacterium from Durban Harbour (South Africa) and its preliminary characterization as Marinobacter sp. KM2

Many aromatic hydrocarbons assigned to the so-called high production volume chemicals (HPVCs) are frequently encountered constituents of wastewaters that end up in the sea. Although the pollutant-degrading capabilities of freshwater bacteria are well known, the catabolism of pollutants by marine bacteria has received limited attention. A marine bacterium with the ability to aerobically utilize phenol - an HPVC and common aromatic pollutant - as its sole source of carbon and energy, was isolated from water samples from Durban Harbour, South Africa. The isolate, designated strain KM2, was assigned to the genus Marinobacter based on a variety of phenotypic properties and by analysis of the 16S rRNA gene sequence. The isolate displays an absolute growth requirement for NaCl which cannot be offset by replacement of NaCl with other salts. In addition to 4-methylphenol and 3,4-dimethylphenol, it utilizes a range of aliphatic hydrocarbons such as butan-1-ol and hexadecane under aerobic conditions. The transient formation of an intermediate exhibiting the UV-Vis spectral characteristics for 2-hydroxymuconic semialdehyde in cultures growing on phenol suggests that the isolate catabolizes this compound via the meta cleavage pathway. These results indicate that members of the genus Marinobacter might participate in the elimination of aromatic pollutants in South African marine environments.

Comparison of larval fish assemblages in three large estuarine systems, KwaZulu-Natal, South Africa

The structure of the larval fish assemblages in three large estuarine systems on the KwaZulu-Natal coast of South Africa was examined using a combination of univariate, distributional and multivariate techniques. The database was comprised of a full annual set of larval fish samples taken from each estuarine system: Durban Harbour, Richards Bay Harbour and St Lucia Estuary. The mean monthly densities of each species in each system were used in the species matrix, and the mean monthly values of salinity, temperature and turbidity were used in the environmental matrix. The mean species diversity and evenness index were significantly higher in Durban Harbour (H′ = 1.03, J′ = 0.65) than in the other two systems. The cumulative dominance curve showed that St Lucia Estuary has a high dominance of a few species, with Richards Bay Harbour intermediate and Durban Harbour being the most diverse. Classification and MDS (multiple-dimensional scaling) analyses of larval fish densities in all three systems grouped together into three main clusters on the basis of system. The species similarity matrix (inverse analysis) clustered into five groups at the 25% similarity level. The MDS analysis of the same matrix showed that the groups separated out according to the degree of estuarine association of a species and hence habitat type. The species most responsible for system groupings were: Glossogobius callidus, Gilchristella aestuaria, Stolephorus holodon, Croilia mossambica and Gobiid 12. The “best fitting” of the environmental variables to explain the larval fish community patterns in each system was turbidity on its own (weighted Spearman's rank correlation, ρw = 0.55). The relationship of larval densities to environmental conditions was shown to be species-specific with estuarine species (e.g. G. callidus and G. aestuaria), having a strong positive correlation with temperature and turbidity but negative correlations with salinity. In summary, much longer term studies with more sites within each system are needed to assess whether the larval fish assemblages are stable or at an equilibrium (both spatially and temporally) and whether these assemblages are indicative of the relative “health” and nursery function of the system.

Composition, abundance and seasonality of fish larvae in the mouth of Durban Harbour, KwaZulu-natal, South Africa

Ichthyoplankton samples were collected every six weeks at night on consecutive ebb and flood tides over an 18-month period (June 1991–December 1992) at surface, middle and bottom depths near the entrance of Durban Harbour to investigate the composition, abundance, seasonality and developmental stages of fish larvae in the harbour. In all, 8 797 fish larvae, representing 144 species and 64 families were collected. The Clupeidae and Gobiidae were the dominant families, representing 30 and 15% of the total catch respectively. The most abundant larvae were the blueline herring Herklotsichthys quadrimaculatus, which contributed 29.7% of the total catch. Larvae of estuarine-independent species dominated the total catch, both in terms of density (78%) and number of species (81%). In all, 28 species dependent on estuaries at some stage in their life cycle were recorded; of these 13 were species totally dependent on estuaries. Temperature and salinity accounted for 31% of the variation in larval densities of estuarine-dependent species. Turbidity was a significant variable for estuarine-independent species, larval densities of the abundant species being negatively correlated to turbidity. Larval density peaked mainly in August 1992 (winter), with a mean larval density of 118 larvae·100m−3. Larvae of estuarine-associated species were mainly at the flexion and postflexion developmental stages, whereas most larvae of estuarine-independent species were at preflexion and flexion stages. Larval densities of certain estuarine-associated species (e.g. Argyrosomus sp.) were significantly higher in bottom samples, mainly on flood tides but also on ebb tides, suggesting that selective tidal stream transport is a recruitment mechanism used by these species. The impact of harbour development is shown by the dominant marine component of the larval fish assemblage in the harbour. However, despite the seminatural estuarine environment of Durban Harbour, the high species diversity of fish larvae in the system indicates that the harbour is in a relatively good ecological condition.

A quantitative assessment of recreational angling in Durban Harbour, South Africa

Durban Harbour is one of the busiest in Africa, its estuarine waters also being a popular angling venue for city-dwellers who pursue their sport from light-tackle boats or from the shores around the 21-km harbour perimeter. Light-tackle boat competition data and shore-angling data from the South African National Marine Linefish System for the years 1976–1991 were used to analyse angler catch rates and catch per species for the Harbour. A total of 85 species of both marine and estuarine-associated ichthyofauna was caught. The Harbour is used as a nursery area by juvenile fish and as a feeding ground and refuge by adult fish. The catch composition varied inter-annually, but it was dominated by the Haemulidae, particularly Pomadasys commersonnii, and the Mugilidae. The majority of fish caught by light-tackle boat anglers were above the minimum legal size, but fell within small size-classes. The catch rate declined over the 16 years, probably attributable to a combination of loss of habitat, flooding in 1987,...

Microbial activity in water overlying the near-shore sand substratum in Natal, South Africa

Small, free-living bacteria have been considered to be either dormant or heterotrophically active and adapted for efficient survival on low concentrations of UDOM (utiiisable dissolved organic material) by way of starvation-survival. They were, in fact, shown to be heterotrophically active in the water column of a subtidal reef in Natal (South Africa), an environment containing UDOM derived from accumulated plant litter. They are more prevalent over the sand substratum between such reefs, where plant litter is transient and the concentration of organic matter (5.4 mg 1-' TOC) is only 30 % of that found on the reef studied. Simple uptake experiments conducted in both summer and winter, using a labelled algal extract (LAE) as substrate, showed the bacteria over the sand to be as active as those over the reef. In most cases, uptake of LAE commenced immediately after addition and progressed Linearly; short-term uptake site saturation possibly occurred in the few remaining cases. Results appear to conform to the starvation-survival theory. The abundance of small, free-living bacteria in the aquatic environment is well documented, recent noteworthy reviews on their role in the marine environment being those of Azam et al. (1983) and Lucas (1986). In some earlier work it was suggested that these bacteria were dormant (Wangersky 1977, Stevenson 1978), but other research clearly showed that they account for considerable heterotrophic activity in many environments (Williams 1970, 1981, Berman 1975, Azam & Hodson 1977, Cole & Likens 1979, Fuhrman 1981, Schleyer 1981). Extensive work of such a nature was carried out on a nearshore, subtropical, subtidal reef in Natal, South Africa (Schleyer 1980, 1981, 1984). These studies supported the latter finding and were later extended to the expansive and less productive sand substratum interspersing Natal's reef systems (Schleyer & Roberts unpubl.). Due to water exchange, the bacterial populations are common to both environments and were found to be almost uniform in number (2 X 106 ml-l), community structure and heterotrophic activity (mean V,,, values of 293 mg C m-3 d-' and 244 mg C m-3 d-' O Inter-Research/Printed in F. R. Germany were obtained over the reef and sand respectively; Schleyer 1984, Schleyer & Roberts unpubl.). The only major difference between the populations is a proportionately greater number of free-living bacteria over the sand (92.8 %; Schleyer & Roberts unpubl.) than over the reefs (79.0 %; Schleyer 1981). However, the populations are spatially and temporally well separated and are distinct in terms of their food availability; bacteria on the reefs have available a rich source of fine particulate and dissolved organic carbon (FPOC and DOC), derived mainly from accumulated plant detritus (Schleyer 19811, in contrast to the sand substratum over which plant litter is merely transient in its passage. Total organic carbon (TOC) levels of only 30 % (F = 5.4 mg I-') of those found on the experimental reef were measured over the sand. The sand environment is thus nutrient-depleted compared to that of the reefs and it was suspected that the 'deprived' bacteria may manifest dormancy. For this reason it was decided that the free-living bacteria over the sand substratum provided a good opportunity to conduct a simple test for dormancy. It had already been established that the incubation of samples with tracer quantities of a labelled algal extract (LAE) elicited 'normal' rates of uptake over a l h period (Schleyer & Roberts unpubl.), so the question posed was whether an induction period was required before uptake commenced. The linearity of progressive uptake of LAE was thus monitored for this purpose. Methods. In 2 separate experiments, conducted in summer and winter, water samples were collected in the surf and backline at beaches off Addington and Sunkist in Durban, South Africa. The former site is roughly 200 m from the nearest reef and is fairly sheltered from wave action by the Durban Harbour breakwaters. The latter is 2.5 km from a groyne, the nearest reef-like feature, and is an exposed, high-energy 102 Mar Ecol. Prog. Ser. 53: 101-103, 1989 As Abs Abb Ss Sbs Sbb