South African Beaches Research Articles

Influence of colourants on environmental degradation of plastic litter

Plastic degradation and the resultant production of microplastics has an important effect on the environment and fauna across the world. This paper shows that the colourant incorporated into plastic formulations has a significant effect on the stability of plastics. A static experimental exposure of differently coloured polypropylene bottle tops from the same manufacturer to a moderate climate over 3 years showed that black, white and silver plastics were almost unaffected whereas the specific blue, green and especially red pigments used in this study were significantly degraded. The second part of the study collected littered HDPE plastic containers from a remote South African beach and analysed their condition as a function of the given manufacturing date stamp. Most items were black or white and samples up to 45 years old were found with relatively little environmental degradation other than mild abrasion. It appears that carbon and titanium dioxide colourants protect the HDPE polymer from photolytic degradation. While anthraquinone, phthalocyanine and diketopyrrolopyrrole pigments were found to enable UV light to degrade the polymer leading to brittle plastics, promoting the formation of microplastics, it is likely that other pigments that do not strongly absorb in the UV will result in similar degradation.

Tracing beach litter sources: Drink lids tell a different story from their bottles

Water and soft drink bottles made from polyethylene terephthalate (PET) sink at sea unless they contain trapped air, whereas their lids are made from polymers that float and can drift long distances. We sampled loose lids and bottles at 21 South African beaches to compare their origins. The proportions of foreign-made bottles and lids were correlated, and increased away from urban centres, indicating that much land-based litter strands close to source areas. Over 80 % of foreign-made drink bottles and 90 % of lids came from Asia, but most bottles were manufactured in China, Malaysia-Singapore and the UAE, and were dumped from ships. By comparison, most loose lids were in poor condition after being carried across the Indian Ocean from Indonesia by the South Equatorial Current. Reducing PET drink bottles at sea requires enforcement of regulations banning dumping at sea, whereas reducing their lids requires better control of littering in source countries.

Effects of COVID-19 lockdowns on shorebird assemblages in an urban South African sandy beach ecosystem

Human pressures are pervasive in coastal ecosystems, but their effect magnitudes are masked by methodological limitations. Government lockdowns associated with the global COVID-19 pandemic can address this gap since lockdowns are effectively manipulations of human presence in ecosystems at scales unachievable otherwise. We illustrate this using a study on shorebirds in an urban South African sandy beach ecosystem. Data collected prior to (2019) and during the COVID-19 (2020) pandemic indicated an inverse relationship between shorebird and human numbers, but this was stronger in 2020. In 2020, human exclusion resulted in a six-fold increase in shorebird abundance relative to 2019. Following easing of lockdowns, shorebird abundance declined by 79.6% with a 34.1% increase in human density. Our findings highlight the sensitivity of shorebirds to recreational disturbance, the potential for current methodological approaches to underestimate repercussions of disturbance and the capacity for COVID-19 lockdowns to refine understanding of human-induced stress in ecosystems.

Exploring Climate Change Threats to Beach Tourism Destinations: Application of the Hazard–Activity Pairs Methodology to South Africa

AbstractClimate change poses significant threats to the sustainability of tourism economies globally. This is particularly true for beach tourism, which is highly dependent on the mean climate, daily weather, and natural setting of a destination to attract and satisfy tourists. This case study of the South African coastline provides new insights to the applicability of the vulnerability assessment methodology of hazard–activity pairs to the global south and specifically to sub-Saharan Africa. Through this method, tourists’ climate perceptions were analyzed and related to potential future impacts of climate change, creating hazard–activity pairs. Tourists’ perceptions of climate were captured by means of a questionnaire. Downscaled CMIP5 climate projections (RCP4.5 and RCP8.5) for six weather stations close to major beach tourism destinations were used to estimate changes in precipitation and temperature. This study reveals that future projections of a mean reduction in precipitation and increasing temperature may have positive rather than negative direct effects on South African beach tourism destinations because what tourists perceive as “comfortable” weather conditions are increasing in prevalence. Nevertheless, indirect and induced effects of an already changing climate, defining further hazard–activity pairs, must be considered in vulnerability assessments. This work endorses the applicability of the hazard–activity pair methodology to South Africa and the global south at large.

Who are the big-spending beachgoers and what is important for them?

Orientation: Beaches attract millions of visitors every year and this has an impact not only on the economy, the environment and the local community but also on current and future beachgoers. Research purpose: The aim of the article is to use expenditure-based segmentation to gain a greater understanding of beach visitor spending in order to identify different markets and the aspects they deem important. Motivation for the study: Although South Africa has a coastline of approximately 3900 km, little is known about the beachgoer to these beaches. This article contributes to the quantification of the economic benefits stemming from beach tourism and in understanding the factors that drive beach visitation. Research approach/design and method: During 2017/18, beachgoers to eight beaches in South Africa were surveyed and 1138 questionnaires were gathered. Using cluster analysis, four segments of beachgoers were identified. The differences between the various segments were explored by using analysis of variance and Pearson’s chi-square. Main findings: The high-spending markets can be distinguished by language, level of education and age, while sunbathing and relaxation are key beach activities. Six key motives for visiting beaches were identified. High-spending markets tend to visit Blue Flag beaches that offer good bathing conditions. Practical/managerial implications: This research identified four segments of visitors to South African beaches, ranging from low-spending locals to high-spending mixed market beachgoers. There are distinct differences between the segments, but important to all segments are the environment qualities of the beach in terms of both cleanliness and beach safety. Contribution/value-add: The research, therefore, concludes that two the main threats to beach tourism and destinations are (1) pollution of the oceans and (2) global warming.

Rapid evolution of leaf physiology in an introduced beach daisy.

Photosynthesis is a key biological process. However, we know little about whether plants change their photosynthetic strategy when introduced to a new range. We located the most likely source population for the South African beach daisy Arctotheca populifolia introduced to Australia in the 1930s, and ran a common-garden experiment measuring 10 physiological and morphological leaf traits associated with photosynthesis. Based on predictions from theory, and higher rainfall in the introduced range, we hypothesized that introduced plants would have a (i) higher photosynthetic rate, (ii) lower water-use efficiency (WUE) and (iii) higher nitrogen-use efficiency. However, we found that introduced A. populifolia had a lower photosynthetic rate, higher WUE and lower nitrogen-use efficiency than did plants from Arniston, South Africa. Subsequent site visits suggested that plants in Arniston may be able to access moisture on a rocky shelf, while introduced plants grow on sandy beaches where water can quickly dissipate. Our unexpected findings highlight that: (1) it is important to compare introduced species to their source population for an accurate assessment of evolutionary change; (2) rainfall is not always a suitable proxy for water availability and (3) introduced species often undergo evolutionary changes, but without detailed ecological information we may not be able to accurately predict the direction of these changes.

Transport of Radium and Nutrients Through Eastern South African Beaches

AbstractSubmarine groundwater discharge (SGD) plays a critical role in coastal and ocean biogeochemistry. Elucidating spatially and temporally heterogeneous SGD fluxes is difficult. Here we use radium isotopes to explore the external sources and mixing regime along the eastern coast of South Africa. We demonstrate that the long‐lived radium isotope compositions are controlled by low inputs of low‐ and high‐salinity terrestrial groundwater. While activities of 228Ra and 226Ra in beach porewaters are similar to coastal waters, 224Ra is enriched by inputs of 228Th from coastal seawater. Porewater ages, based on the production of 224Ra from 228Th, range from 0.3 to 2.3 days, indicating rapid flushing of the beach system. Unlike radium, however, nutrients follow a more complex pathway. We hypothesize that high total dissolved nitrogen (TDN) and phosphorus concentrations in beach porewaters (TDN ranges from 1 to >700 μM) and the coastal ocean (TDN ranges from 1 to >40 μM) are derived from a source not enriched in radium. We speculate that this source is terrestrial water flowing below the dune barrier at depths exceeding our beach sampling depths. This water likely flows upward through breaches in the confining layer into the beach or enters the ocean directly through paleochannels. The presence of high nutrient concentrations in the coastal ocean unaccompanied by high 228Ra activities leads to the hypothesis of this additional nutrient source. These combined inputs may be of considerable importance to the coastal ecology of southeastern Africa, an oligotrophic ecosystem dominated by the nutrient‐poor Agulhas Current.

Rapid beachrock cementation on a South African beach: Linking morphodynamics and cement style

Rapid cementation (<5 years) of beachrock is reported from the wave-dominated, microtidal coastline of Durban, South Africa. The beachrock is developing at mean sea level on a steep (10°–30°), reflective beach prone to periodic erosion by high-energy wave action; the most recent erosional event resulted in retrogradation of the beach by up to 10 m landward of the beachrock outcrop discussed in this study. Transmitted light microscopy and scanning electron micrographs show the precipitation of two dominant cement types which are linked to the beachface morphodynamics. During the accreted beach phase, when the locus of beachrock formation lay well landward of the beachface in the undersaturated upper intertidal to supra tidal backbeach, meniscus cements were precipitated. Following a period of erosion, associated with a landward shift of the beachface, the incipient beachrock was then exposed to saturated conditions which promoted growth of acicular cements. Contemporary beachrock cementation occurred very rapidly (<5 years) between significant erosional events. The observed cement textures record short-term beach progradation and retrogradation but are similar to those typically associated with longer-term regression and transgression.

Marine debris pathways across the southern Indian Ocean

The distribution of marine debris both with the open oceans and along coastlines is largely governed by surface currents and thereby dependent upon seasonal circulation patterns and annual variability inherent in the major current systems. The recovery of a satellite-tracked current drifter on a South African beach some 22 months after release off Western Australia was an indicator of the ocean-wide processes operating in the southern Indian Ocean gyre. Using this single drift trajectory in combination with data from other current drifters released along the Western Australian coast between 2008 and 2013, from earlier satellite-tracked drifters and a selection of historical drift bottle returns, drift patterns across the southern Indian Ocean between Western Australia and east Africa were analysed to quantify inter-continental debris transport rates via the South Equatorial Current (northern east-west pathway) and the South Indian Ocean Current (southern west-east pathway). The northern east-west trans-ocean pathway can be considered in three segments: the complex and highly variable Leeuwin Current eddy system in the east, which can retain drifting debris for up to a year, the comparatively uniform westward travel in the South Equatorial Current, and the eddying components in the western boundary current system off southern Africa. A simple Eddy Activity Index is derived here to clearly distinguish the Leeuwin Current eddy region from the South Equatorial Current. The southern route to Australia is simpler via the Agulhas Return Current and the South Indian Ocean Current.

Consistent patterns of debris on South African beaches indicate that industrial pellets and other mesoplastic items mostly derive from local sources

Identifying the sources of small plastic fragments is challenging because the original source item seldom can be identified. South Africa provides a useful model system to understand the factors influencing the distribution of beach litter because it has an open coastline with four equally-spaced urban-industrial centres distant from other major source areas. We sampled mesodebris (∼2–25 mm) at 82 South African beaches in 1994, 2005 and 2015. Plastic items comprised 99% by number and 95% by mass of litter items. Industrial pellets were the most abundant plastic items, but fragments of rigid plastic items comprised most of the mass of debris. Strong correlations between industrial pellets and other plastic items indicate that common factors influence the distribution of both pellets and secondary mesoplastics. The abundance of mesodebris at beaches also was correlated in successive surveys, suggesting that beach-specific factors (e.g. aspect, slope, local currents, etc.) influence the amounts of debris on each beach. Sample year had no effect on mesodebris abundance, indicating that there has been little change in the amounts of mesodebris over the last two decades. There were consistently higher densities of both industrial pellets and other plastic items at beaches close to urban-industrial centres; there were only weak correlations with human population density and no correlation with local runoff. The size of industrial pellets decreased away from local urban centres, further supporting the conclusion that, like macroplastic litter, most mesoplastic pollution on continental beaches derives from local, land-based sources. This finding means that local actions to reduce plastics entering the sea will have local benefits, and that it may be possible to assess the efficacy of mitigation measures to reduce marine inputs of mesoplastic items.

An assessment tool for sandy beaches: A case study for integrating beach description, human dimension, and economic factors to identify priority management issues

Sandy beaches offer invaluable services, the overexploitation of which threatens their survival. Management responses may be inappropriate, focussing on limited aspects of beaches and neglecting key characteristics. This study developed and tested a new integrated assessment tool for sandy beaches, using seven recreational South African beaches as case study. The tool was based on a beach description matrix, forming the Beach Description Index; an assessment of beachgoers’ attitude and opinion, forming the Human Dimension Index; and a monetary assessment, forming the Monetary Index. Values for each index were classified according to management attention/recreational favourability, opinion/attitude, and economic value, respectively. The average of the indices formed a Beach Evaluation Index, which was used to rate the performance of and compare the case study beaches. Within limits, the evaluation tool successfully identified management priorities, public concerns, and economic aspects regarding the beaches, all of which can be generalised to other beaches worldwide.

Quantifying cumulative threats to sandy beach ecosystems: A tool to guide ecosystem-based management beyond coastal reserves

Managing marine ecosystems to promote natural functioning and provide for sustainable use is a necessary complement to formal conservation in protected areas. Because the area for conservation and resources for management are limited, both sites and actions need to be prioritized. Sandy beaches are poorly recognised as ecosystems, and thus are neither well managed nor regularly included in conservation initiatives, and are highly threatened. Therefore, we aim to refine an existing cumulative threat assessment (CTA) for beach ecosystems, the outputs of which can inform prioritization of beaches for conservation in reserves and/or various management objectives beyond reserves. We focus on the latter, using the CTA to derive a decision-support tool that aims to provide for use of sandy shores, whilst ensuring their ecological functioning is not compromised. The CTA depends on expert-based scores of threats to ecosystems; these were determined at the VIth International Sandy Beach Symposium (2012) for a baseline scenario under two criteria: functional impact and recovery time. Application of the CTA and decision-support tool is illustrated using the South African beaches. The baseline threat scores were adapted to suit the local context, and spatial trends in the cumulative impact of 15 threats were quantified. South African beaches are exposed to a broad range of cumulative pressure: overall it is relatively low, except where beaches are associated with areas of intensive coastal development. Based on the degree of permanent modification of the shore, and cumulative impact of all other stressors, the decision-support tool classifies beaches as: social-priority areas; ecological-priority areas; or social-ecological areas, each with specific management objectives.

Rich diversity, strong endemism, but poor protection: addressing the neglect of sandy beach ecosystems in coastal conservation planning

AbstractAimSpatially‐explicit trends in species richness and endemism on sandy shores are quantified to assess representation of beach ecosystems in existing reserve networks. Also, the relative importance of different drivers of species distributions are compared through species distribution modelling.LocationThe South African beaches are among the best‐studied in the world, providing sufficient biological data for the analyses. There is also a well‐established coastal protected‐area network that putatively provides moderate protection to nearly all beach habitats.MethodsSpecies distribution maps of beach‐dependent vertebrates, macrofauna, microflora, and foredune vegetation were compiled from existing sources or modelled using standard techniques. While some data were available for the latter analyses, additional sampling was required to improve bioregional coverage. Each species' distribution was coded to a detailed map of the South African shoreline. Representation of habitats and species in various configurations of existing reserves was determined.ResultsOverall, 535 species have been recorded on the South African sandy shores, including 139 common species. Endemism is variable among taxonomic groups. Notably, two‐thirds of the macrofauna are regional endemics, half of which are endemic to South Africa. For almost all of the common species, &lt; 20 % of their distributions are protected in land‐sea reserves. Protection of beach habitats is similarly poor; conservation targets were not met in all cases, and most habitat types are considered Poorly Protected.Main conclusionsSandy beach communities are considerably more diverse than they are generally acknowledged to be, and comprise a unique suite of biota. Given the species' narrow distributions and high degree of exposure to threats, many probably qualify as threatened/endangered. In spite of this, beaches are poorly represented in coastal reserve networks. To redress this issue, conservation planners need to account for beaches specifically, and to ensure they are represented in contiguous land‐sea protected areas.

Surf zone diatoms: A review of the drivers, patterns and role in sandy beaches food chains

The accumulation of high biomass of diatoms in the surf zone is a characteristic feature of some sandy beaches where the wave energy is sufficiently high. A few species of diatoms, called surf diatoms, thrive in this harsh environment. The main processes driving the spatial and temporal distribution of surf diatoms as well as their standing biomass and growth were described twenty to thirty years ago based on studies conducted on the western coast of the United States of America and South African beaches. Since then, over fifty locations around the world have been reported to have surf diatom accumulations with most (three-quarters) of these being in the southern hemisphere. Their occurrence is controlled by physical and chemical factors, including wave energy, beach slope and length, water circulation patterns in the surf zone and the availability of nutrients to sustain the high biomass. The main forces driving the patterns of temporal variability of surf diatom accumulations are meteorological. In the short term (hours), the action of wind stress and wave energy controls the diatom accumulation. In the intermediate time scale (weeks to months), seasonal onshore winds of sufficient strength, as well as storm events are important. Furthermore, anthropogenic disturbances that influence the beach ecosystem as well as large-scale events, such as the El Niño Southern Oscillation, may lead to significant changes in surf diatom populations in the long term (inter-annual). Surf diatoms form the base of a short and very productive food chain in the inshore of the sandy beaches where they occur. However, the role of surf diatoms in the microbial food web is not clear and deserves further studies.

Phil Hockey (1956-2013)

Phil Hockey (1956-2013)

Beachgoers' Awareness and Evaluation of the Blue Flag Award in South Africa

Lucrezi, S. and van der Merwe, P., 2015. Beachgoers' awareness and evaluation of the Blue Flag Award in South Africa.Beach awards such as the European Blue Flag are increasingly adopted in many countries as an environmental brand to promote better beach management and encourage tourism. However, the validity of the Blue Flag award has been criticized in the literature, and research shows that the award is still not widely known and has marginal influence on tourists' beach selection. This study, conducted at six popular South African beaches, three with and three without Blue Flag status, investigated awareness and evaluation of the Blue Flag award among 579 beachgoers. Results from a structured questionnaire showed that over half of the participants, mostly people on the Blue Flag beaches, knew about the Blue Flag award and its criteria; however, approximately one-third of the participants were unaware of it. Participants tended to be less tolerant of supposed water-quality degradation than the loss of the Blue Flag status, although an exception was made for Margate Beach, where people were less tolerant of a hypothetical loss of Blue Flag status. Although the participants' evaluation of the Blue Flag award was generally positive, for most it was not their main reason for visiting a beach. In the light of these findings, a more coherent implementation of the Blue Flag award and better information propagation in its regard are recommended for South African beaches.

Long-term decreases in persistent organic pollutants in South African coastal waters detected from beached polyethylene pellets

Polyethylene pellets provide a convenient means to monitor Persistent Organic Pollutants (POPs) in marine systems. Pellets collected between 1984 and 2008 at three South African beaches were analysed for PCB, HCH and DDT. Concentrations of all three POPs decreased over the last two decades, although this signal was less clear for PCBs, and further monitoring is needed to assess trends in this family of compounds. DDT concentrations at two sites were higher than previous records for southern Africa, but there is no evidence of a link to the ongoing use of DDT for malaria control. HCHs concentrations were lower than in pellets from the east coast of southern Africa, suggesting that this pesticide was mainly used in the eastern part of the region. Our study demonstrates the potential for International Pellet Watch to track temporal as well as geographical patterns in the abundance of POPs in marine environments.

Strength and power characteristics of elite South African beach volleyball players

This study investigated the strength and power characteristics of 13 elite South African male beach volleyball players. The results indicate that elite beach volleyball players have a mean stature of 185.28 cm (;7.2), mean mass of 82.01 kg (;9.7) and percentage body fat of 13.12% (;2.4). Mean isokinetic peak torque values (Nm) for leg extension at 60 degrees . s -1=268.03, 180 degrees . s-1=188.53, and 240 degrees . s-1=162.61; leg flexion at 60 degrees . s-1=152.65, 180 degrees . s-1=117.65 and 240 degrees . s-1=104.61. Mean isokinetic peak torque values for leg extension relative to body mass (Nm. kg-1) were for extension at 60 degrees . s-1=3.29, 180 degrees . s-1=2.37, and 240 degrees . s-1=2.0 and flexion at 60 degrees . s-1=1.86, 180 degrees . s-1=1.45 and 240 degrees . s-1=1.29. Vertical jump performance (VJP) was evidenced by an average of 61.73 cm (;4.5). The results suggest that elite beach volleyball players have relatively strong legs when compared with studies that assessed sportsmen using isokinetic devices at the same testing speeds. VJP was however modest when compared to previous studies of elite indoor volleyball players. (S. African J. for Research in Sport, Physical Ed. and Recreation: 2002 24 (1): 29-40)

HUMAN RECREATIONAL PATTERNS ON BEACHES WITH DIEFERENT LEVELS OF DEVELOPMENT

SUMMARY Three South African beaches, King's Beach, Joorst Park and Sardinia Bay, with different levels of development, were selected to study the recreational use patterns over a holiday cycle by means of aerial photography and questionnaire surveys. King's Beach was classified as developed, Joorst Park as semi-developed and Sardinia Bay as undeveloped on the basis of the number of facilities present. Differences in popularity, use patterns, size and age composition of visitor groups, times of peak visitor abundance, types of accommodation and transport used, distance travelled and time spent on the beach were observed. The most developed beach consistently received the most visitors (of higher socio-economic level) as determined by visitor abundance at 11:00, except on New Year's Day, when the semi-developed Joorst Park received the highest numbers of visitors (6 500). This beach, frequented mainly on public holidays by visitors of a low socio-economic level from the nearby township, remained relatively unused during the rest of the holiday season. The other beaches, in contrast, were more continually used by visitors with private cars. Visitor group size was largest at the semi-developed Joorst Park. Visitors older than 50 years were more abundant at the undeveloped Sardinia Bay than at the other beaches, seeking the peace and quiet that this beach provides. Camping was most prevalent amongst the visitors to Joorst Park due to lack of other cheap accommodation there. Also, visitors to Joorst Park stayed on the beach for longer periods and a higher percentage of the respondents travelled long distances to the beach than on the other beaches. Although recreation patterns were linked to the level of beach development, other factors not related to beach development, such as cultural/ethnic background, political/historical influences, socio-economic level of beach users and distance of the beach from the visitor's home also played an important role. Environmental education emerges as one of the most urgent needs to properly manage dune and beach use in South Africa.

Shark and skate egg-cases cast up on two South African beaches and their rates of hatching success, or causes of death

Collections of chondrichthyan egg-cases cast ashore at two sites along the South African coastline were identified and examined for cause of mortality. A total of 574 egg-cases collected from False Bay could be attributed to five species of scyliorhinid shark, two skates and the elephantfish or chimaera, while the 538 egg-cases collected from Port Alfred belonged to four scyliorhinid sharks and two skate species. At both sites eggs of shy-sharks of the genus Haploblepharus made up more than 70% of the samples, followed by skates (5% in False Bay and 19% in Port Alfred) and then catsharks of the genus Poroderma (1 and 7% respectively). Haploblepharus egg-cases generally displayed relatively high rates of hatching success of over 60% and predation rates of 18-30%. Haploblepharus fuscus was the exception with a low hatching success of 37% and a predation rate of 40%. Poroderma egg-cases suffered predation losses of 43%, and had a hatching success of 47%. Skate egg-cases displayed non-predator induced egg mor...