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The supralittoral zones of sandy beaches are particularly vulnerable to coastal development and other activities that cause localised habitat destruction. Supratidal species, such as peracarid crustaceans, which lack a pelagic larval phase and tend to avoid direct contact with the swash, are therefore expected to be distributed as isolated populations, with implications for their long-term survival. Genetic population structure of one such species, the pill bug Tylos capensis, was investigated based on mitochondrial cytochrome c oxidase subunit I (COI) haplotype sequences, to assess demographic history and regional population connectivity in the presence of potential dispersal barriers (an estuary, coastal cliffs) along the Indian Ocean coast of South Africa. Here, pill bugs demonstrated strong and significant genetic structure at the regional scale, with 3 distinct clades across the species’ geographic distribution. At a localised spatial scale, coastal cliffs intersecting the high shore appeared to be a strong barrier to gene flow between adjacent populations, while a permanently open estuary did not limit gene flow. Estimates of historic gene flow and patterns of COI differentiation coincided with greater habitat continuity during the Pleistocene glaciations at sea levels between -75 and -120 m, when the African south coast was probably dominated by sandy beaches. While gene flow among low-dispersing pill bug populations is unlikely to benefit from a network of closely spaced coastal protected areas, the isolated nature of this species, coupled with the cryptic diversity inherent in this taxon, emphasizes the need for their protection. The importance of protecting the intact littoral active zone of beaches is highlighted.

South Africa has a long history of engagement in citizen science (CS), particularly marine CS. This review examines the contributions made by marine CS, from the 1930s through to the current era, where websites, social media and mobile apps provide a wide range of opportunities. Largescale marine CS projects, such as the Oceanographic Research Institute’s Cooperative Fish Tagging Project, have made enormous contributions to marine scientific research. Individual citizen scientists have also made considerable contributions, particularly in taxonomy and the publication of field guides. Marine CS has also contributed towards the popularisation of science and improved scientific literacy through the active engagement of many citizens. These benefits align well with the visions of policies that currently guide the South African marine research agenda. However, marine CS in the developing world is not without challenges, and practitioners should be cognisant of the time and effort required to initiate and maintain viable CS initiatives. Especially, long-term successful CS projects depend on secure, ongoing funding, institutional support and enthusiastic champions. Participation by almost exclusively the urban and middle-class sectors of society is also of concern. These challenges can be addressed through stakeholder-inclusive planning, development of novel methods that engage with broader sectors of society, and regular critical evaluations of CS projects. Where global projects on the intended taxa/subject of study already exist, it may also be preferable to enter into collaborative data-sharing agreements with these to reduce operational costs and avoid duplication.

Our understanding of the importance of microbiomes on large aquatic animals—such as whales, sea turtles and manatees—has advanced considerably in recent years. Recent activity describing epizoic diatoms suggests that epibiotic diatom communities constitute diverse, polyphyletic, and compositionally stable assemblages that include both putatively obligate epizoic and generalist species. Here, we outline a successful attempt to culture putatively obligate epizoic diatoms without their hosts and propose further applications and research avenues in this growing area of study. Analyzing the DNA sequences of these cultures, we found that several unique diatom taxa have independently evolved to occupy in epibiotic habitats. We created a library of reference sequence data for use in metabarcoding surveys of sea turtle and manatee microbiomes that will further facilitate the use of environmental DNA for studying host specificity in epizoic diatoms and the utility of diatoms as indicators of host ecology and health. Our discovery that epizoic diatoms can be cultured independently from their hosts raises several questions about the nature of the interaction between these diatom species and their hosts. We encourage the interdisciplinary community working with marine megafauna to consider including diatom sampling and diatom analysis into their routine practices.

Sea turtles are long-lived migratory species that are sensitive to anthropogenic impacts. Their condition reflects that of marine ecosystems and can serve as an indicator for environmental monitoring. However, evaluating body condition parameters, as a proxy for health, is challenging and often overlooked. The purpose of this study was to validate a straightforward method for assessing the body condition of nesting loggerhead sea turtles (Caretta caretta), and to investigate whether body condition was correlated with epibiont loading. To achieve this, 60 nesting loggerhead sea turtles were sampled and categorized into five body conditions ranging from very poor to very good. Injuries, skin deformities and plastron shape were used for this classification. Epibionts were collected from the same turtles and identified, with species richness, diversity, community structure and barnacle loading compared among body conditions. Epibiont communities were correlated with body condition as both species richness and abundance increased with a decline in turtle body condition. Barnacle epibionts showed great variation among different body conditions, having significantly higher numbers on turtles in poor condition. All parameters in this study showed similar distinctive relationships with body condition of loggerhead turtles from poor to very good body condition. The body condition index used in this study can be applied readily and, along with barnacle counts, can provide basic baseline information on turtle health.

Background: Our understanding of the importance of microbiomes on large aquatic animals—such as whales, sea turtles and manatees—has advanced considerably in recent years. Recent activity describing the epizoic diatoms growing on marine vertebrates suggests that these epibiotic diatom communities constitute diverse, polyphyletic, and compositionally stable assemblages that include both putatively obligate epizoic and generalist species. Here, we outline a successful attempt to culture putatively obligate epizoic diatoms without their hosts and propose further applications and research avenues in this growing area of study. Results: We cultured cells of epizoic diatoms from multiple host species sampled in the wild and captivity. Analyzing the DNA sequences of these cultures, we found that several unique diatom taxa have independently evolved to occupy in epibiotic habitats. We created a library of reference sequence data for use in metabarcoding surveys of sea turtle and manatee microbiomes that will further facilitate the use of environmental DNA for studying host specificity in epizoic diatoms and the utility of diatoms as indicators of host ecology and health. Conclusions: Our discovery that epizoic diatoms can be cultured independently from their hosts raises several questions about the nature of the interaction between these diatom species and their hosts. We encourage the interdisciplinary community working with marine megafauna to consider including diatom sampling and diatom analysis into their routine practices.

More than 130 late Pleistocene trackway sites from the coastal eolianites and beach deposits of the Cape south coast, South Africa, have previously mostly yielded tracks of large mammals and birds. However, two sites east of Still Bay, and a third near Garden Route National Park, yield distinctive trackways of hatchling sea turtles, made during the short posthatching (postemergence) interval when the trackmakers headed for the sea. One assemblage of approximately parallel trackways indicates smaller loggerhead turtle hatchlings, with alternating gaits, and contrasts with a wider trackway indicating a leatherback turtle hatchling. These are the world's first reports of fossil traces that document this brief “run-for the-sea” phenomenon. They help delineate late Pleistocene sea turtle breeding ranges and indicate climatic conditions along the Cape south coast. Ichnotaxonomically defined swim tracks of large adult sea turtles are known from a few Mesozoic sites. Likewise, walking and swim traces of terrestrial freshwater turtles are also known from the Mesozoic and Cenozoic. However, as no ichnotaxonomy exists for these diagnostic hatchling trails, we assign the trackways of the inferred loggerheads to the new ichnotaxon Australochelichnus agulhasii ichnogen. et ichnosp. nov., and the inferred leatherback trackway to Marinerichnus latus ichnogen. et ichnosp. nov.

The world's beaches are under severe pressure because of anthropogenic modification and climate change. The most common coastal management approaches have focused largely on the protection of infrastructure without considering the function of the beach and dune system as a natural protective barrier and a diverse ecosystem. Large-scale plantations of non-native vegetation have been initiated in many countries as a coastal protection tool. However, exotic trees commonly used for bio-shields, such as Casuarina equisetifolia, have been shown to have negative effects on the coastal environment, including the promotion of beach erosion in some instances and negative impacts on sea turtles. The aim of the study was to determine if exotic Casuarina spp. enhance the vulnerability of turtle nesting beaches by exacerbating erosion. The extent of use of exotic Casuarina spp. was assessed on 50 important sea turtle nesting beaches of the Indian Ocean and South-East Asia (IOSEA) region and used an adapted Coastal Vulnerability Index (CVI) to determine vulnerability of these beaches to erosion. Sites were assessed using long-term global data sets under four risk indicators (backshore width, beach exposure, modal beach energy, dune state) and three threat indicators (coastal development, sea-level rise and storminess). Beach vulnerability was then classified into four categories: 1) High Risk-High Threat; 2) High Risk-Low Threat; 3) Low Risk-High Threat and 4) Low Risk-Low Threat. Overall, Casuarina trees were present on 28% of beaches, and seem to be a popular management option in the IOSEA region. Lepidochelys olivacea rookeries were most affected by Casuarina, which is of concern because these populations are already considered at risk from other stressors. Overall, beaches tended to have higher risk than threat, and beaches with Casuarina present were not shown to be more vulnerable to erosion (Kruskal-Wallis Χ244 = 42.62, p = 0.5308). However, these trees may pose other threats to sea turtles, e.g., providing obstructions to nesting females and altering nest incubation environments, which need to be carefully considered by decision makers. Ideally, natural dune cordons need to be maintained and restored, conferring benefits of protection to people, and benefits of ecological processes to biodiversity.

Beaches are interesting ecosystems on which to test foraging ecology because the resident fauna mostly depend on unpredictably supplied allochthonous food resources. This study tests the food selection of two beach scavengers with different foraging strategies. Ghost crabs (Ocypode ryderi) patrol along the shore in search of food; it was predicted that, if given equal choices, they would select the most calorie-rich food. In contrast, swash-riding plough snails (Bullia spp.) need to make immediate decisions whether to emerge from the sand to feed on a beach-cast food item before it is washed away. It was predicted that they would emerge in response to all food equally because there is no guarantee of a better meal in their immediate future. These predictions were tested in two different in situ experiments that simulated natural foraging conditions for each scavenger. Ghost crabs consumed fish (highest calorific value) significantly more often than other foods. Similarly, significantly more snails responded to fish (higher calorific value) than jellyfish (lower calorific value); a result that was consistent with snail size, but was not affected by food-cue concentration. Beach scavengers are well adapted to the challenges of the ecosystem, and although food is supplied unpredictably, they still select for high-quality food, supporting optimal foraging theory. It is hypothesized that the patchy distribution of resident macrofauna on sandy shores may (partly) reflect their foraging ecology, sensu the ideal free distribution theory.

The current study focuses on four species from the primarily marine diatom genus Craspedostauros that were observed growing attached to numerous sea turtles and sea turtle-associated barnacles from Croatia and South Africa. Three of the examined taxa, C. danayanus sp. nov., C. legouvelloanus sp. nov., and C. macewanii sp. nov., are described based on morphological and, whenever possible, molecular characteristics. The new taxa exhibit characters not previously observed in other members of the genus, such as the presence of more than two rows of cribrate areolae on the girdle bands, shallow perforated septa, and a complete reduction of the stauros. The fourth species, C. alatus, itself recently described from museum sea turtle specimens, is reported for the first time from loggerhead sea turtles rescued in Europe. A 3-gene phylogenetic analysis including DNA sequence data for three sea turtle-associated Craspedostauros species and other marine and epizoic diatom taxa indicated that Craspedostauros is monophyletic and sister to Achnanthes. This study, being based on a large number of samples and animal specimens analyzed and using different preservation and processing methods, provides new insights into the ecology and biogeography of the genus and sheds light on the level of intimacy and permanency in the host-epibiont interaction within the epizoic Craspedostauros species.

Loggerhead sea turtles (Caretta caretta) occupy an array of marine habitats throughout their lives and understanding how this threatened species utilizes these habitats can help guide conservation efforts. This study used a combination of isotopic analysis (δ13C; δ15N) of turtle epidermis and epibiotic community composition to examine habitat-use patterns of nesting loggerheads from the South West Indian Ocean and related these to turtle body condition. First, we identified two foraging groups using relative changes in the turtle’s epidermis δ13C isotope values (of 170 individuals). Second, we show that epibiont communities (of 80 turtles) differed significantly between the two foraging groups, with oceanic/pelagic and neritic/benthic species occurring in higher abundances on turtles with depleted and enriched δ13C values, respectively. The complementary evidence from isotope and epibiont data thus indicates that nesting loggerheads of this population exhibit a bimodal foraging strategy. The relatively high variability in δ13C and δ15N values of the turtles’ tissue showed that they have a broad isotopic niche. While isotopic niches overlapped among turtles with different body conditions, very healthy individuals had a significantly narrower isotopic niche width than those in poorer condition. This suggests that turtles in very good condition are food specialists, and individuals with suboptimal body conditions utilise a wider range of food items and are more generalist foragers. These results show the value of using a combination of stable isotopes and epibiont communities as cost-effective tools that can be applied effectively to derive information on habitat-use patterns of migratory species.

Beach protection and monitoring has been used for about half a century to multiple rookeries globally as an effective sea turtle conservation strategy with successful population recovery at some. Loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) turtles nesting in South Africa have been continuously protected and monitored since 1963, representing one of the longest running sea turtle beach monitoring programs in the world (>54 years). Evidence suggests that these previously harvested populations are growing, as illustrated by increased numbers of nesting females and proportion of new recruits in the nesting cohort. A 35-year time series of consistently conducted nesting beach survey was used to assess trends in female sizes over time for both species. Despite increased nesting numbers, a significant 3.7 and 3.6 cm decrease in the size of both recruit and remigrant female loggerhead turtles, but a stable mean size of leatherbacks for both age groups is observed. We hypothesize that these contradictory effects are attributable to the very distinct foraging ecologies of the two turtle species and speculate that the variation in carapace length may be driven by environmental change. Further research is needed to examine the impacts of a decreased or increased female turtle size on reproductive outputs and overall population growth. The trends observed in this study emphasize the importance of long-term monitoring, examining not only abundance, but also individual size, to understand population dynamics and support recovery planning and conservation practices.

Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement-based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species' 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of 50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.

Organic matter transfer across ecosystem boundaries strongly influences consumer populations and food web dynamics. Consequently, it is hypothesized that sandy beaches, which are organic matter-limited ecosystems and almost exclusively subsidized by allochthonous inputs, should respond to pulses of organic matter. Large quantities of organic matter in the form of eggs are deposited on the high shore of tropical and subtropical beaches during the turtle nesting season. This study quantifies the response of meiofauna to the decomposition of turtle eggs over time. Meiofaunal densities were first measured in predated nests. Second, the response of meiofauna to organic matter inputs over time were quantified experimentally, in situ, by comparing meiofauna communities from five artificially predated pseudo-nests with those from five control pseudo-nests, sampled daily at three depths for 3 weeks. There was a strong temporal response of the meiofauna in the experimental treatment compared to that in the controls. After 5 days, the meiofaunal communities in the experimental treatment were significantly different to those in the control treatment, with abundance of all taxa higher in the experimental treatments, particularly nematodes. The peak of the response (maximum nematode abundance: 2.5 × 105 ind·cm3) was observed after 7 days. Thereafter, their abundance declined until it returned to the background density (

Animal movement underpins many ecological processes, and thus plays a key role in maintaining functional ecosystems. Sandy shores are an interesting model system on which to study animal movement because they are physically dominated, and the resident animals are generally very small ( 2000 snails in each of six occasions (three on neap tides; three on spring tides), released them from a single fixed point, and recaptured them for four consecutive days following release. Each day, a standard suite of physical variables was also measured at low tide. The majority of snails maintained their position along the shore and remained close to the release point, however, some moved up to several hundred meters alongshore per day in both directions away from the release point. Overall, the average maximum daily displacement (daily “step-length”) was 100 m; this was independent of animal size and tide state. However, when considering the maximum cumulative distance travelled (furthest distance attained relative to the release point per day), tide state and time were significant drivers of B. rhodostoma movement, with animal size playing a secondary role. The latter may be because of differences in animal density and foot size with increasing snail size, translating into differences in tidal migrations and alongshore displacement. Overall B. rhodostoma, like other beach macrofauna species, largely maintain their alongshore position at a local scale, but also have the potential to disperse much further even as adults. Of the variables measured, it seems that external forcing (beach morphology and wave/swash climate) is more important for driving B. rhodostoma movement than are intrinsic drivers (size). However, there are other intrinsic variables not tested here, e.g., state of hunger, that may be important as well. The limitations of the study notwithstanding, we present a low-cost, low-technology method for estimating beach-animal movement that could be easily applied to test other related questions.

International audience; Phenological shifts, by initiating reproductive events earlier, in response to advanced seasonal warming is one of the most striking effects currently observed in wild populations. For sea turtles, phenological adjustment to warming conditions could be the most effective short-term adaptation option against climate change. We calculated future phenological changes required in seven important loggerhead (Caretta caretta) nesting populations to continue achieving a high hatching success and a sex ratio that lies within current ranges. Considering temperature-mediated phenological changes, we found that most populations (six out of seven) will not be able to keep pace with a warming climate. Under an optimistic climate warming scenario (RCP4.5), these populations will face a climatic debt, that is, a difference between required and expected phenological changes, and warming will substantially reduce hatching success and induce a feminization of hatchlings, which may jeopardize their reproductive sustainability. Our approach offers the possibility to quantify the efficiency of phenological shifts in oviparous reptiles by considering physiological, developmental and phenological processes.

A new Lucanicum species, L. ashworthianum Majewska, K.Robert & Van de Vijver sp. nov., was found in multiple samples of biofilm growing on loggerhead sea turtles Caretta caretta and their symbiotic barnacles Chelonibia testudinaria collected on the beaches of Kosi Bay, eastern coast of South Africa, during the two nesting seasons (the austral summers of 2017/2018 and 2018/2019). The new species possesses several features typical of the genus Lucanicum, including the uniseriate striae composed of one large macroareola, the presence of large apical slit fields and transapically elongated rimoportulae at both poles, and a cingulum composed of numerous open, doubly perforated copulae. It differs from the only other Lucanicum species known to date, the coral-associated L. concatenatum, in having considerably smaller cells with clearly rostrate or sub-capitate apices and internal rimoportula opening composed of a C-shaped inner lip and an oval, flap-like outer lip - a feature not observed previously in Lucanicum. Based on these new observations, an amendment of the genus description is proposed.

The diatom genus Proschkinia is a common element of biofilms covering diverse substrata in saline inland or shallow coastal environments. It can be distinguished from other naviculoid taxa by its lanceolate valves with a fistula located within the central area and numerous open girdle bands with a U-shaped cross-section and a single row of perforations on the internal side of the fold. Despite this distinct morphology, frustules of Proschkinia are typically weakly silicified and often overlooked when cleaned diatom material is analysed. The current paper describes six new species of Proschkinia: P. browderiana sp. nov., P. lacrimula sp. nov., P. maluszekiana sp. nov., P. sulcata sp. nov., P. torquata sp. nov. and P. vergostriata sp. nov., found in numerous samples of marine organisms, such as sea turtles (including sea turtle museum specimens), sea turtle-associated barnacles and seagrass from across the three oceans. Some of the newly described taxa were found on multiple individuals belonging to different sea turtle species, whereas others were in samples collected from different continents. Molecular phylogenetic analysis indicated that examined Proschkinia strains formed a monophyletic clade, sister to Fistulifera.

Twenty-four of 40 (60%) loggerhead turtle Caretta caretta post-hatchlings (carapace < 9 cm) that died within 2 months of stranding on southern Cape beaches in April 2015 contained ingested anthropogenic debris. Plastic comprised of 99% of debris: 77% hard plastic fragments, 10% flexible packaging and 8% fibres; industrial pellets comprised only 3%, compared to ~ 70% in 1968–1973, when 12% of stranded post-hatchlings contained plastics. Turtles selected for white (38%) and blue (19%) items, but translucent items (23%) were under-represented compared to beach mesodebris. Ingested loads did not decrease up to 52 days in captivity, indicating long retention times. Plastic killed 11 turtles by blocking their digestive tracts or bladders, and contributed to the deaths of five other turtles. Our results indicate that the amount and diversity of plastic ingested by post-hatchling loggerhead turtles off South Africa have increased over the last four decades, and now kill some turtles.

Marine unconsolidated sediment habitats, the largest benthic ecosystem, are considered physically controlled ecosystems driven by a number of local physical processes. Depth and sediment type are recognised key drivers of these ecosystems. Seascape (i.e., marine landscape) habitat classifications are based solely on consistent geophysical features and provide an opportunity to define unconsolidated sediment habitats based on processes which may vary in distribution through space and time. This paper aimed to classify unconsolidated sediment seascapes and explore their diversity in an eastern boundary upwelling region at the macro-scale, using the South African west coast as a case study. Physical variables such as sediment grain size, depth and upwelling-related variables (i.e., maximum chlorophyll concentration, austral summer bottom oxygen concentration and sediment organic carbon content) were included in the analyses. These variables were directly measured through sampling, or collated from existing databases and the literature. These data were analysed using multivariate Cluster, Principal Components Ordination and SIMPER analyses (in PRIMER 6 + with PERMANOVA add-in package). There were four main findings; (i) eight seascapes were identified for the South African west coast based on depth, slope, sediment grain size and upwelling-related variables, (ii) three depth zones were distinguished (inner, middle and outer shelf), (iii) seascape diversity in the inner and middle shelves was greater than the outer shelf, and (iv) upwelling-related variables were responsible for the habitat diversity in both inner and middle shelves. This research demonstrates that the inclusion of productivity and its related variables, such as hypoxia and sedimentary organic carbon, in seascape classifications will enhance the ability to distinguish seascapes on continental shelves, where productivity is most variable.

Threatened species are dependent on conservation, with strategic approaches underpinned by the principle of complementarity to find efficient solutions. But are paper-efficient designs always field-effective? After 51 years of monitoring a 56-km-long overlap of two turtle rookeries, there are contrasting population-recovery trends: Vulnerable loggerhead abundance is increasing; and Critically Endangered leatherback abundance is remaining constant, despite leatherback individuals having a higher reproductive output. This questions the efficacy of the conservation programme (annual monitoring and land–sea protection in a World Heritage Site). We use biotelemetry to test if the disparate recovery is biased by differences in detectability in the monitored section of the rookery, and if the reserve confers equal protection. The species' movement ecology contrasts strongly, with implications for nest-event detectability: ~ 66% of leatherback nesting is outside the monitoring area, compared to ~ 12% of loggerhead nesting. The marine reserve also strongly favours loggerheads at 95% protection, versus 25% protection for leatherbacks. We hypothesize that variability in leatherback movement ecology, and nest placement, is from ocean currents shaping their behaviour as hatchlings, potentially also determining the proportion of the population at risk of capture in pelagic fisheries. Efficient multi-species conservation strategies need to be carefully designed and adaptive to be effective.

The knowledge gap on the early life-history of sea turtles during the “lost years” continues to hinder research and conservation of this critical life stage when mortality rates are the highest. An oceanic model was used in combination with a Lagrangian particle tracking framework to simulate and identify potential post-hatchling dispersal trajectories of loggerhead and leatherback turtles in the South Western Indian Ocean. The study aimed to investigate the effect of hatchling swimming behaviour on hatchling dispersal and survival probability. To our knowledge, this study provides the first estimate of neonate sea turtle dispersal in the SWIO, by combining a particle tracking model with in situ hatchling behavioural data. The model revealed that most virtual hatchlings are transported south-westward in the Agulhas Current with three distinct final locations after a year-long simulation (each zone comprising on average > 20% of the total amount of particles): the Agulhas Return, the SE Atlantic and the Southern Ocean zones. However, because loggerhead hatchlings are less strong swimmers compared to leatherbacks, they can be advected northward in the near-shore coastal current. Simulations revealed that initial active swimming (frenzy) as well as variability in oceanic conditions strongly influenced dispersal of virtual hatchlings. Furthermore, variability in oceanic conditions dispersed virtual hatchlings into different areas where threats, like fisheries bycatch, might also influence their survival. Lastly, the results of this study have potentially broad implications for climate change if turtles adapt by nesting earlier/later during the nesting season or further south which may influence hatchling locomotor performance and ultimately survival at early life stages.

Fitness theory attempts to explain how organisms survive by understanding not survival as such but the design that confers the highest survival. This study investigated the effects of phenotypic variation on the reproductive strategy (clutch and egg size) of loggerhead and leatherback sea turtles as well as the influence of size on hatchling fitness traits. We examined whether larger females produced larger hatchlings of higher fitness by testing two hypotheses; the optimal egg size theory, and the bigger is better hypothesis. The study investigated how maternal length influences reproductive output (clutch size, egg size), and how hatchling morphology affects their performance. Hatchling performance was analysed by measuring two correlates of fitness, crawling and swimming speeds, as these two traits positively influence their survival by minimising the time of exposure in highly predated areas. The reproductive strategy of both loggerhead and leatherback turtles nesting in South Africa was found to support the optimal egg size theory whereby larger turtles produce larger clutches but not larger eggs. Egg size was constant irrespective of maternal length. The low contribution of female body size to clutch size variability suggests that other factors are affecting female reproductive output during a nesting season. Hatchling fitness assessment trials demonstrated that hatchlings with longer carapaces and flippers lengths swam faster. This adds to the growing body of evidence suggesting that larger hatchlings are more likely to survive because they spend less time in high predation risks areas (i.e. beach and nearshore) and thus assumed fitter than smaller ones. These findings have implications for overall population growth/recovery if smaller hatchlings of lower fitness are produced and have decreased dispersal abilities and thus lower likelihood of survival.

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.

Scenario planning can be useful to guide decision-making under uncertainty. While systematic conservation planning can create protected-area networks for multiple and complex reserve-design scenarios, planners rarely compare different reserve networks explicitly, or quantify trade-offs among scenarios. We demonstrate the use of multivariate statistics traditionally applied in community ecology to compare reserves designed under different scenarios, using conservation planning for beaches in South Africa as an example. Twelve reserve-design scenarios were run in Marxan in a hierarchical experimental design with three levels: including/excluding the probability of site destruction; two different cost types; and three different configurations of existing terrestrial and marine reserves. Multivariate statistics proved to be useful tools in the conservation planning context. In our case study, they showed that the trade-off associated with including the probability of site destruction during coastal reserve design depended on the cost type: if the cost is related to the site-destruction probability then reserves are significantly larger; if not, then reserves are significantly more costly. In both cases, the configuration of existing reserves locked a priori into the solutions was more important and resulted in significantly larger and more costly reserves.Synthesis and applications. This study demonstrates a novel application of multivariate statistical tools to robustly quantify potential trade-offs among diverse sets of reserve-design scenarios. These statistics can be applied: to support negotiations with stakeholders and decision-makers regarding reserve configurations in the face of uncertainty; in reserve-design sensitivity analyses; and in priority setting for future research and data collection to improve conservation plans.

Representative and adequate reserve networks are key to conserving biodiversity. This begs the question, how much of which features need to be placed in protected areas? Setting specifically-derived conservation targets for most ecosystems is common practice; however, this has never been done for sandy beaches. The aims of this paper, therefore, are to propose a methodology for setting conservation targets for sandy beach ecosystems; and to pilot the proposed method using data describing biodiversity patterns and processes from microtidal beaches in South Africa. First, a classification scheme of valued features of beaches is constructed, including: biodiversity features; unique features; and important processes. Second, methodologies for setting targets for each feature under different data-availability scenarios are described. From this framework, targets are set for features characteristic of microtidal beaches in South Africa, as follows. 1) Targets for dune vegetation types were adopted from a previous assessment, and ranged 19–100%. 2) Targets for beach morphodynamic types (habitats) were set using species–area relationships (SARs). These SARs were derived from species richness data from 142 sampling events around the South African coast (extrapolated to total theoretical species richness estimates using previously-established species–accumulation curve relationships), plotted against the area of the beach (calculated from Google Earth imagery). The species-accumulation factor (z) was 0.22, suggesting a baseline habitat target of 27% is required to protect 75% of the species. This baseline target was modified by heuristic principles, based on habitat rarity and threat status, with final values ranging 27–40%. 3) Species targets were fixed at 20%, modified using heuristic principles based on endemism, threat status, and whether or not beaches play an important role in the species' life history, with targets ranging 20–100%. 4) Targets for processes and 5) important assemblages were set at 50%, following other studies. 6) Finally, a target for an outstanding feature (the Alexandria dunefield) was set at 80% because of its national, international and ecological importance. The greatest shortfall in the current target-setting process is in the lack of empirical models describing the key beach processes, from which robust ecological thresholds can be derived. As for many other studies, our results illustrate that the conservation target of 10% for coastal and marine systems proposed by the Convention on Biological Diversity is too low to conserve sandy beaches and their biota.

This note demonstrates the effect of locus variability and demographic history on the estimation of genetic differentiation and its interpretation in terms of ecological connectivity. Cytochrome c oxidase subunit I (COI, mtDNA) sequences of the beach clam Donax serra from four sites along the South African coast were analysed. D. serra showed low COI haplotype diversity ( h = 0.30 ± 0.069, 7 haplotypes), suggesting expansion from a small source population into extant habitats. As a consequence, statistical power to measure genetic connectivity was low. The lack of genetic population structure therefore does not necessarily demonstrate high connectivity. Although COI has been used successfully to identify species and populations isolated for prolonged periods of time, lack of differentiation has to be interpreted with caution, especially in terms of extant patterns of connectivity.

Open-ocean sandy beaches are coastal ecosystems with growing relevance in the face of global change. They provide key ecosystem services, such as storm buffering, nutrient cycling, water purification, nursery habitats for resource species, and feeding-breeding habitats for focal species (e.g. endangered sea turtles and shorebirds), and have also become nodes for economic development and cultural use. As a result, beaches face a range of threats, primarily from extractive use, habitat modification and development, sea-level rise and coastal squeeze. Consequently, balancing conservation of the ecosystem and sustainable use of the goods and services is particularly important for sandy shores. Thus, the only way to ensure their protection and continued provision of their valuable services, especially in a period of rapid global change, will be to apply knowledge generated from sound science in beach conservation and management. Here we aim to (1) identify and outline the broad ecological paradigms in sandy beach science; (2) report on a citation analysis of the published literature of the past 63 years (1950–2013) to provide context regarding the topics and location of research, the size and institutional composition of the research teams; and (3) investigate whether beach ecology can and has been incorporated into integrated coastal zone management practices. Past research was framed by specific paradigms (chiefly the Swash Exclusion Hypothesis and derivatives), which can be identified with distinct principles and concepts unique to beaches. Most of the sandy beach literature comes from only a few countries (dominated by USA, South Africa, Brazil and Italy), published by small research teams (

Bio-monitoring of pollutants in long-lived animals such as sea turtles is an important tool in ecotoxicology. We present the first report on metallic elements in sea turtle eggs from the Indian Ocean. Eggs of the leatherback and loggerhead turtle that breed on the Indian Ocean coast of South Africa were analysed for 30 elements. The eggshells and egg contents of the loggerhead turtle, the smaller of the two species, had higher or significantly higher concentrations than leatherbacks, except for strontium - the reason is unknown. Elemental concentrations in eggshells and contents were the same or lower compared with other studies. The differences in concentrations in the egg contents and eggshells between the two species are likely due to different trophic levels, migration patterns, life histories, age, and growth, as well as differences in pollution sources and the uptake, retention and elimination characteristics of the different elements by the different species. We found no congruence between patterns in eggshells and corresponding egg contents, for both species. However, eggshells and egg contents showed congruence between species. The lack of congruence between eggshells and contents within each species precludes using eggshell concentrations as a proxy for egg content concentrations. Copper, strontium, and selenium occurred at concentrations higher than available toxic reverence values. Further research is warranted, including the analyses of POPs, as well as possible deme discrimination based on compositional pattern differences. Turtles serve as 'active samplers' returning to the same location to breed-something that is not practical with marine mammals or elasmobranchs.

Aim Spatially-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. Location The 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. Methods Species 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. Results Overall, 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

Average age and size at first reproduction are important demographic parameters used in the management and conservation of populations. For sea turtles, absolute values for these parameters are still ambiguous, as most species are slow-growing, late-maturing migrants which are rarely encountered during the first 1 to 2 decades of their lives. Additionally, growth is signif- icantly influenced by a variety of intrinsic and extrinsic factors which make it difficult to describe agesize relationships. Extensive notching (mutilation-tagging) of South African loggerhead tur- tles was used to determine age and size at reproduction (putative first nesting season), and thus to identify the trigger for sexual maturation. To date, 137 clearly identified notched adult females have been encountered at the nesting beach. A Gaussian and log-normal distribution were fitted to the age distribution data but only the Gaussian distribution can be used to safely estimate age at first observation, as the right part ('older ages') of the distribution is still unknown. The esti- mated age at first observation was corrected for the possibility that a female was not encountered during her first nesting season. Results indicate an average age of 36.2 ± SD 7.71 yr (95% CI 28.2 to 44.3 yr) with a straight carapace length (SCLmin) of 83.7 ± 4.15 cm (95% CI 83.0 to 84.4 cm). It was concluded that size is a more important threshold for the initiation of the maturation process than age and that the onset of sexual maturity is dependent on intrinsic and extrinsic factors.

Previous studies have shown that the world’s largest reptile – the leatherback turtle Dermochelys coriacea – conducts flexible foraging migrations that can cover thousands of kilometres between nesting sites and distant foraging areas. The vast distances that may be travelled by migrating leatherback turtles have greatly complicated conservation efforts for this species worldwide. However, we demonstrate, using a combination of satellite telemetry and stable isotope analysis, that approximately half of the nesting leatherbacks from an important rookery in South Africa do not migrate to distant foraging areas, but rather, forage in the coastal waters of the nearby Mozambique Channel. Moreover, this coastal cohort appears to remain resident year-round in shallow waters (Caretta caretta. The rare presence of a resident coastal aggregation of leatherback turtles not only presents a unique opportunity for conservation, but alongside the presence of loggerhead turtles and other endangered marine megafauna in the Mozambique Channel, highlights the importance of this area as a marine biodiversity hotspot.

Coastal ecosystems are highly vulnerable to human-mediated drivers of global change because they are located at the land–ocean interface and often host centres of urbanisation and development. The South African coastline comprises several distinct coastal ecoregions that support a wide range of coastal (inshore) ecosystems, including rocky, sandy and mixed shores, kelp beds, estuaries and seagrass communities. A growing body of evidence indicates that local air and sea temperatures, wind patterns, ocean current speed and upwelling regimes are all being affected by human-mediated climate change. In addition, anthropogenic activities, such as shipping (introducing coastal bioinvasives), exploitation of coastal marine resources, industry (releasing pollutants) and urban development, act synergistically with climate change to place pressure on coastal ecosystems and their biota. The aim of this review was primarily to synthesise and update research into causes of direct and indirect human-mediated global change and their effects on South African coastal systems. It incorporates both historic and the latest regional research on climate change and anthropogenic threats across the ecosystems listed above, much of which was supported by the South African Network for Coastal and Oceanic Research (SANCOR), specifically the SEAChange programme in recent years. It is evident that all these ecosystems are vulnerable to all the drivers considered, albeit to differing degrees, depending on their location on the coast. Whereas some bioinvasives have had a dramatic impact on rocky shore systems on the West Coast, their impact has been moderate on the South Coast and minimal on the East Coast; exploitation shows the reverse pattern. Furthermore, the impacts of human-mediated drivers on coastal ecosystems are synergistic. Of major interest is the fact that the West Coast and parts of the South Coast are exhibiting cooling trends in offshore sea surface temperatures, rather than warming. Correspondingly, a geographical spread of organisms associated with West and South-West Coast rocky shores and kelp beds has tended to be eastwards around Cape Point, rather than northwards along the West Coast as would have been expected with warming sea temperatures. Overall, significant progress has been made toward a better understanding of the combined pressures on each ecosystem and knowledge gaps have been identified, thus helping to direct future research themes.Keywords: anthropogenic, bioinvasives, climate change, coastal development, exploitation, pollutionAfrican Journal of Marine Science 2013, 35(3): 403–425

The Benguela Current Large Marine Ecosystem off southwest Africa is a regionally valued system because of its biological productivity, which supports high biomass throughout the foodweb, and a rich diversity of habitats and species. However, the region is exposed to numerous anthropogenic pressures that are likely to escalate under future economic growth. In response, the Benguela Current Commission called for a spatial biodiversity assessment (BCC-SBA) to identify conservation priorities, including potential areas for marine protected areas. The systematic conservation-planning approach to this assessment requires a fine-scale map of coastal habitats, which was not previously available for the region. Our aim was to undertake this mapping, within tight logistic and resource limitations. We used a previously derived methodology for mapping the distribution of coastal habitats from aerial imagery. The Benguela coast is approximately 5,047 km long. Half of this extent is sandy beach, a third is rocky and mixed shores, 13 % comprises lagoonal features, and the remainder (4 %) comprises estuaries and offshore islands. The distribution and extent of these coastal habitats differs substantially alongshore (i.e. with latitude), with conditions ranging north–south from hot, humid mangrove-lined lagoons, to hyper-arid coastal desert sandy beaches. Patterns in regional geology, climate and oceanography are proposed as the main drivers of spatial heterogeneity in coastal habitat types. The resulting ecological and socio-economic wealth requires proactive protection (supported through the BCC-SBA, for example), to ensure sustainable utilization of the rich natural resources, and persistence of these resources for the benefit of current and future generations.

Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement-based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species' 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine50 years of conservation, potentially affecting80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.

Shark nets were established along the KwaZulu-Natal coast in 1952 to protect bathers against shark encounters. Sea turtle bycatch data for the period 1981–2008 in these shark nets indicated that loggerheads Caretta caretta were caught most frequently at 40.9 y-1 or 1.11 km-net-1 y-1, followed by green turtles Chelonia mydas at 0.32 km-net-1 y-1 and leatherbacks Dermochelys coriacea at 0.14 km-net-1 y-1. Catch rate of loggerheads increased throughout the study period, and was positively correlated with the increase in the number of nesting females from the recovering population in Maputaland, South Africa (r = 0.52, p < 0.05, n = 28). This increase is ascribed to successful nest conservation. Leatherback bycatch remained stable, following their nesting trends, although they receive similar conservation efforts on nesting beaches as loggerheads. Bycatch of green turtles, although not a nesting species in South Africa, was stable over time. Mortality varied between species (from 53.2% to 70.6%) with loggerheads being the most hardy, followed by leatherbacks and green turtles. Few hawksbills Eretmochelys imbricata and olive ridleys Lepidochelys olivacea were caught in the shark nets. Fewer sea turtles are caught by shark nets than by longlines and because the nesting populations of loggerheads, green turtles and leatherbacks are either stable or increasing in the South-West Indian Ocean, shark net bycatch was considered negligible and sustainable. Keywords: bycatch, CPUE, green turtle, leatherback, loggerhead, mortality, seasonality, sex ratioAfrican Journal of Marine Science 2012, 34(2): 249–257

Santidrián Tomillo, Pilar et al., The most recent climate change projections show a global increase in temperatures along with precipitation changes throughout the 21 century. However, regional projections do not always match global projections and species with global distributions may exhibit varying regional susceptibility to climate change. Here we show the effect of local climatic conditions on the hatchling output of leatherback turtles (Dermochelys coriacea) at four nesting sites encompassing the Pacific, Atlantic and Indian Oceans. We found a heterogeneous effect of climate. Hatchling output increased with long-term precipitation in areas with dry climatic conditions (Playa Grande, Pacific Ocean and Sandy Point, Caribbean Sea), but the effect varied in areas where precipitation was high (Pacuare, Caribbean Sea) and was not detected at the temperate site (Maputaland, Indian Ocean). High air temperature reduced hatchling output only at the area experiencing seasonal droughts (Playa Grande). Climatic projections showed a drastic increase in air temperature and a mild decrease in precipitation at all sites by 2100. The most unfavorable conditions were projected for Sandy Point where hatching success has already declined over time along with precipitation levels. The heterogeneous effect of climate may lead to local extinctions of leatherback turtles in some areas but survival in others by 2100., Funding for the study was provided by a Marie Curie International Incoming Fellowship within the 7th European Community Framework Programme. Specific funding for each site was provided by the Earthwatch Institute, the Betz Chair of Environmental Science at Drexel University, the Schrey Chair of Biology at IPFW and The Leatherback Trust (Playa Grande), the US Fish and Wildlife Service (USFWS) (Sandy Point), the Endangered Wildlife Trust (Pacuare) and NRF/Thuthuka and NMMU Postgraduate Research Scholarship (Maputaland)

Storms can have a large impact on sandy shores, with powerful waves eroding large volumes of sand off the beach. Resulting damage to the physical environment has been well-studied but the ecological implications of these natural phenomena are less known. Since climate change predictions suggest an increase in storminess in the near future, understanding these ecological implications is vital if sandy shores are to be proactively managed for resilience. Here, we report on an opportunistic experiment that tests the a priori expectation that storms impact beach macrofaunal communities by modifying natural patterns of beach morphodynamics. Two sites at Sardinia Bay, South Africa, were sampled for macrofauna and physical descriptors following standard sampling methods. This sampling took place five times at three- to four-month intervals between April 2008 and August 2009. The second and last sampling events were undertaken after unusually large storms, the first of which was sufficiently large to transform one site from a sandy beach into a mixed shore for the first time in living memory. A range of univariate (linear mixed-effects models) and multivariate (e.g. non-metric multidimensional scaling, PERMANOVA) methods were employed to describe trends in the time series, and to explore the likelihood of possible explanatory mechanisms. Macrofaunal communities at the dune-backed beach (Site 2) withstood the effects of the first storm but were altered significantly by the second storm. In contrast, macrofauna communities at Site 1, where the supralittoral had been anthropogenically modified so that exchange of sediments with the beach was limited, were strongly affected by the first storm and showed little recovery over the study period. In line with predictions from ecological theory, beach morphodynamics was found to be a strong driver of temporal patterns in the macrofaunal community structure, with the storm events also identified as a significant factor, likely because of their direct effects on beach morphodynamics. Our results also support those of other studies suggesting that developed shores are more impacted by storms than are undeveloped shores. Whilst recognising we cannot generalise too far beyond our limited study, our results contribute to the growing body of evidence that interactions between sea-level rise, increasing storminess and the expansion of anthropogenic modifications to the shoreline will place functional beach ecosystems under severe pressure over the forthcoming decades and we therefore encourage further, formal testing of these concepts.