South African Coast Research Articles

Resolving the taxonomic identities and genetic structure of two cryptic Platynereis Kinberg species from South Africa

The perceived cosmopolitanism of polychaete worms could be an artefact of historical factors such as poor original species descriptions, lack of type material and the European taxonomic bias, to name a few. Thus, it is possible that several cosmopolitan species hide complexes of cryptic and pseudocryptic species. Two putative cosmopolitan species, Platynereis dumerilii and Platynereis australis, collected in South Africa were investigated here (1) to determine whether the South African taxa are conspecific with the morphologically identical taxa from France and New Zealand (the respective type localities of P. dumerilii and P. australis), (2) to compare the South African species morphometrically to determine whether their morphological characters are reliable enough to separate them, and (3) to investigate whether these species have geographically structured populations along the coast of South Africa. Molecular data (COI and ITS1) confirm that P. dumerilii and P. australis do not occur in South Africa. Instead, the South African taxon formerly thought to be Platynereis dumerilii is new and is described here as Platynereis entshonae, sp. nov.; the identity of the other South African species is currently unresolved and is treated here as Platynereis sp. Surprisingly, Platynereis massiliensis (type locality: Marseilles) nested within the South African Platynereissp. clade but, since it is part of a cryptic species complex in the Mediterranean, the name is considered doubtful. Morphological characters traditionally used to define these South African Platynereis species are not reliable as predefined morphological groupings do not match phylogenetic clades and principal component scores revealed no separation in morphological characters that could distinguish between them. Haplotype networks and phylogenetic trees revealed that P. entshonae, sp. nov. and Platynereis sp. have geographically structured populations along the South African coast. http://zoobank.org/urn:lsid:zoobank.org:pub:6E36A210-9E48-430F-8A93-EDC27F0C5631

Six Pre-Colonial Portuguese Shipwrecks Identified on the South African Coast:The Legacy of Bartolomeu Dias

For hundreds of years European merchants had undertaken successful trade missions to the eastern markets; crossing overland, they operated from the city states of Genoa, Pisa, Amalfi and Venice. When the overland route was blocked by the Ottoman Turks, an alternative route was planned. To the rulers of Spain and Portugal, the only possibility was to find a sea route to the east, and a sea route around Africa was considered feasible by the rulers of Portugal. Under the guidance of Prince Henry of Portugal, the son of Joao I, the coast of Africa was slowly explored. By 1483 CE Diego Cao had reached Cape Cross on the desolate Namibian coast. Joao II, sanctioned the next expedition, which was led by Bartolomeu Dias, who left Lisbon in 1487 CE. His instructions were to go round the southern tip of Africa and attempt to establish contact with Prester John, the mythical Christian king, whose cooperation was considered essential to break the Moslem monopoly on African trade. This article deals with precolonial Portuguese shipwrecks off the South African coast, engaged in trade voyages during Portugal’s dominance of the Indian ocean route to India.

Ethnobotanical research at Klasies River linking past, present, and future

Background: Klasies River is a prominent archaeological site on the South African southern Cape coast, with a unique and continuous occupation spanning the Middle and Late Pleistocene into the Holocene. Ethnobotanical research was undertaken with the objective of enabling a deeper understanding and contextualisation of the palaeo-ethnobotanical finds retrieved during ongoing excavation. Methods: Research into ethnobotanical usage enables extrapolation of the uses to which archaeobotanicals may have been put. Semi-structured interviews and walks in the veld with six local participants, selected for their knowledge of the local plants, were conducted. An interdisciplinary focus, with a pragmatic and abductive grounded theory approach was used. Results: Of the Klasies taxa reported in use today by participants 84% are confirmed by other published research into Khoi and San indigenous plant knowledge in the three Cape Provinces and 42% of these useful taxa are reported as finds in published archaeological research in the Cape Provinces, indicating ongoing usage from past to present. Conclusions: Our research indicates the need for thorough and systematic collection of ethnobotanical data (particularly from Khoi and San descendants), which is under-studied in the South African context. We consider that environment and behaviour of the past, present and future is not only shaped by climate, but by adaptive human-plant interactions through intergenerational and inter-cultural learning. Keywords: Useful plants; medicinal plants; archaeobotany; Khoi and San; indigenous knowledge;

Post-Late Glacial Maximum Palaeoecological Species Integrity, Phylogeography and Management of Bontebok (Damaliscus pygargus pygargus)

Re-evaluation of bontebok following a multidisciplinary approach indicate its native habitat as the now submerged Palaeo-Agulhas Plain off the southern South African coast, and dominated by C4 grasslands and savannah. Large grazer populations migrated across the plain and around the eastern end of the Cape Folded Belt into the Eastern Cape interior following climate oscillations and geographic-shifts of the winter-/summer-/all-year rainfall isohyets. Presently 77% of all bontebok are found on private farmland with grassland bioregions in the Eastern Cape, Free State and other. Bontebok showed enhanced performance in these grasslands if compared with poor performance on south-western Cape Lowland Renosterveld (SWC-LRV). Renosterveld (RV) was previously perceived as the bontebok's native habitat of origin. We argue that bontebok became trapped in RV due to sea-level rises and consequent multiple species congestion. Bontebok meta-population management on private farms showed significant species improvement when compared with government conservation actions in SWC-LRV. Geographic habitat constraints appear to have been the greatest factor limiting bontebok integrity. IUCN recognizes a global population size of 1,618 as reported by the Non-Detriment Finding of the Scientific Authority of South Africa, whereas actual population size is more than 7,000. We quantify post-1930s bontebok performance against phylogeographic and palaeoclimate proxies.

Apparent temperature as a modifier of the effects of air pollution on respiratory disease hospital admissions in Secunda, South Africa

TPS 681: Short-term health effects of air pollutants 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Due to climate change, an increase of 34°C in ambient temperature is projected along the South African coast and 6-7°C inland during the next 80 years. Very few studies in Africa investigated effect modification by a temperature indicator (e.g. apparent temperature, Tapp) on the human health effects of air pollution. Methods: Respiratory disease (RD) admission data (ICD10 J00-J99) were obtained from MediClinic for the two hospitals located in Secunda; after ethics approval. The study period is 1 January 2011 to 31 October 2016. NO2, SO2, PM10, PM2.5, temperature and relative humidity data were obtained from the South African Weather Services. A case-crossover epidemiological study design was applied. The present study focused on lag0-1; as most other studies. Models were adjusted for public holidays and Tapp. Days with Tapp below and above/equal the median (14.9C) were classified as cold and warm days, respectively. Results: Of the 14 568 RD admissions, approximately equal number of females and males were admitted. 47%, 45% and 8% of the admissions were from 0-14, 15-64 and >=65 year olds, respectively. The daily NO2, SO2, PM2.5 and PM10 levels were 12.4, 8.5, 32.3 and 68.6 μm/m3, respectively. Daily air pollutant levels regularly exceeded the WHO guidelines. On cold days there were no significant associations between the air pollutants and RD admissions, but there were strong associations on warm days, except for NO2. On warm days, 0-14 year olds and females were more susceptible to PM2.5, PM10 and SO2, e.g. RR 1.12 95%CI 1.02-1.23 for 14 year olds and PM2.5 compared to the unstratified analyses RR 1.01 95%CI 1.00-1.02. Conclusions: These results indicate that the risk of RD hospital admission due to ambient air pollution exposure is different on cold and warm days in Secunda.

Halogenated natural products and anthropogenic persistent organic pollutants in chokka squid (Loligo reynaudii) from three sites along the South Atlantic and Indian Ocean coasts of South Africa

Chokka squid (Loligo reynaudii) from three sites along the South African coast were analyzed for halogenated natural products (HNPs) and anthropogenic persistent organic pollutants (POPs). HNPs were generally more than one order of magnitude more abundant than POPs. The most prevalent pollutant, i.e. the HNP 2,3,3′,4,4′,5,5′-heptachloro-1′-methyl-1,2′-bipyrrole (Q1), was detected in all chokka squid samples with mean concentrations of 105, 98 and 45 ng/g lipid mass, respectively, at the Indian Ocean (site A), between both oceans (site B) and the South Atlantic Ocean (site C). In addition, bromine containing polyhalogenated 1′-methyl-1,2′-bipyrroles (PMBPs), 2,4,6-tribromophenol (2,4,6-TBP, up to 28 ng/g lipid mass), polybrominated methoxy diphenyl ethers, MHC-1, TBMP and other HNPs were also detected. Polychlorinated biphenyls (PCBs) were the predominant class of anthropogenic POPs. PCB 153 was the most abundant PCB congener in chokka squid from the Indian Ocean, and PCB 138 in samples from the South Atlantic Ocean and between both oceans.

Exploitation may influence the climate resilience of fish populations through removing high performance metabolic phenotypes

Physiological rates and processes underpin the relationships between ectothermic organisms, such as fish, and their environment. The response and persistence of fish populations in an increasingly variable ocean is dependent on the distribution and diversity of physiological phenotypes. Growing evidence suggests that fisheries exploitation can selectively target certain physiological and behavioural phenotypes, which may shift exploited populations to altered physiological states. Here we test if commercial fisheries have the potential to do this in a “natural laboratory” along the South African coast. We compare metabolic traits of exploited and protected populations of the fish species, Chrysoblephus laticeps, which is a major component of the South African hook and line fishery. We find that high-performance aerobic scope phenotypes are reduced in the fished population. The most likely mechanism for this finding is a positive relationship between aerobic scope and capture vulnerability in passive-gear fisheries. Our results further highlight the selective nature of capture-fisheries and suggest that exploitation has the capacity to alter climate responses of fish populations on a physiological level. Our finding also implicates how Marine Protected Areas, through harbouring individuals with a greater diversity of physiological traits, may provide greater fish response diversity to environmental variability.

Geological and soil maps of the Palaeo-Agulhas Plain for the Last Glacial Maximum

The South African Cape South Coast is bordered by one of the broadest continental shelves in Africa. The Agulhas Bank, inshore shelf and presently exposed coastal plain make up the Palaeo-Agulhas Plain (PAP), though our area of study extends beyond this limit and as far inland as the first mountain belt. Quaternary sea levels have been significantly lower than at present for ∼90% of the Pleistocene, exposing a terrestrial ecosystem on what is now the submerged shelf. The presently drowned component makes up 94% of the total area of the PAP. Past work has hypothesised a contrast in character of this submerged landscape when compared to the subaerial environment. Here, we assimilate newly-acquired geophysical and geological datasets to produce geological- and soil maps from the Last Glacial Maximum on a scale of 1:750,000, covering an area of ∼55,000 km. Three broad geomorphic zones are defined, including the Western section from Cape Agulhas to Cape Infanta, the Central section from Cape Infanta to Knysna and the Eastern section extending eastward of Knysna. We demonstrate that Mesozoic sedimentary deposits crop out near the surface on this current-swept shelf and soils derived from siltstone and shale bedrock are prominent when the coast is up to 64 km distant from the modern shoreline at its maximum point. Beyond this, weathered limestone dominates the substrate sequences on the Agulhas Bank. We show that the submerged landscape was a unique terrestrial environment and that there is no exact modern-day analogue in the region other than a small (∼70 km2) area located at the edge of the Agulhas Plain near Cape Agulhas, and map major contrasts in the geological, topographic and edaphic nature of the landscape from the onshore to the offshore. The expansion of this plain is coupled with exaggerated floodplains, meandering shallowly incised rivers and wetlands. The submerged shelf is dominated by fertile soils compared to the dissected onshore belt, and extensive calcareous dunefields extending up to 10 km inland from their associated palaeoshorelines covered much of the emergent shelf. Sedimentary bedforms may have obstructed or slowed drainage as suggested by leached palaeosols and carbonate mixing observed in petrographic thin sections and grain mounts. The data show a low-relief “plains” landscape, which contrasts strongly to the topographically complex contemporary coastal foreland.

Narrating Whales in Southern Africa

Though the whaling stations on the South African coast are now closed, whaling in the southern oceans, both ‘illegal’ and ‘scientific’, continues to be a matter of controversy. Exploitation clashes in complex ways with whale-watching as a touristic activity, now a major drawcard to South Africa’s coastline. It appears no thorough survey of the history and sociology of whaling has yet been written, nor of the progression of those emotional investments in the presence of whales that drive animal rights programmes and tourism alike. Such literature on whales as exists in southern Africa throws interesting sidelights on this presence. This article explores the issues through such literary works as Douglas Livingstone’s poetry and the fictions of Laurens Van Der Post, Zakes Mda, Lyall Watson and Mia Couto.Keywords: Whales, whaling, Southern Africa, fiction, poetry, Laurens van der Post, Zakes Mda, Mia Couto, Lyall Watson

Comparison of climate and environment on the edge of the Palaeo-Agulhas Plain to the Little Karoo (South Africa) in Marine Isotope Stages 5–3 as indicated by speleothems

Given the steep present-day climatic gradients in southern South Africa, comparative studies of its coastal and inland paleoclimate provide important insight into the region's spatial climate dynamics. We present a comparative study of new speleothem stable oxygen (δ18O) and carbon (δ13C) isotopic composition from Efflux Cave (EC; 113–19 ka, hiatus between 105 and 94 ka) in the Little Karoo inland basin and Herolds Bay Cave (HBC; 93–62 ka) at the boundary between the Cape coastal lowlands and the Palaeo-Agulhas Plain. Gaussian kernel based cross-correlation analyses against palaeoclimate proxy records show that rainfall seasonality at EC is related to rainfall amount in the South African interior, whereas HBC is similar to the South African east coast. Our new proxy records, corroborated by archaeological evidence from the Cape coastal lowlands and the Little Karoo, suggest that in both regions, surface water was readily available and grassland ecosystems with variable amounts of C4 and C3 grasses as well as fynbos communities could be found nearby. Cross-correlation analyses of the new records from EC and HBC compared to previously published speleothem records from southern South Africa show only limited statistical correlation. However, there are some similarities in overall trends of palaeoclimate change in the Cape coastal lowlands and the Little Karoo whereby Marine Isotope Stage (MIS) 5b (mainly Greenland Interstadial 22) and 4 generally have more summer rainfall and higher abundances of C4 vegetation than MIS 5a and MIS 3.

Using GIS and cartography as part of the whole-of-society approach to determine coercion into marine wildlife poaching and piracy

Abstract. This paper builds on a previous paper on determining a community’s vulnerability to coercion into wildlife crimes along South African game reserves with a focus on rhinoceros poaching. This paper looks at the profiling of coastal communities along the South African coast for possible coercion into piracy and marine wildlife crime as context for a whole-of-society approach. As with the previous paper the criteria and data are based on publicly available resources to do the profiling. Criteria range from access to motorised boats, history of illegal, unregulated and unreported fishing activities, poverty, unemployment, closeness to marine reserves and levels of education. The criteria for piracy are based on articles and reports on the reasons for piracy along the Somalian coast. From the analysis the highest risk for piracy is the south-western Cape around Cape Town since the proximity to international sea routes, the ability of the local population to do deep-sea fishing and existing gang activity. The risk to marine resources is similar owing to the same reasons as for piracy. It is a known fact that gangs are involved in the poaching of abalone along the south-western Cape coast. Socio-economic risks are higher along the east coast of South Africa owing to higher unemployment, poverty and lower education levels.

Biogeographical Patterns of Endolithic Infestation in an Invasive and an Indigenous Intertidal Marine Ecosystem Engineer

By altering the phenotypic properties of their hosts, endolithic parasites can modulate the engineering processes of marine ecosystem engineers. Here, we assessed the biogeographical patterns of species assemblages, prevalence and impact of endolithic parasitism in two mussel species that act as important ecosystem engineers in the southern African intertidal habitat, Perna perna and Mytilus galloprovincialis. We conducted large-scale surveys across three biogeographic regions along the South African coast: the subtropical east coast, dominated by the indigenous mussel, P. perna, the warm temperate south coast, where this species coexists with the invasive Mediterranean mussel, M. galloprovincialis, and the cool temperate west coast dominated by M. galloprovincialis. Infestation increased with mussel size, and in the case of M. galloprovincialis we found a significantly higher infestation in the cool temperate bioregion than the warm temperate region. For P. perna, the prevalence of infestation was higher on the warm temperate than the subtropical region, though the difference was marginally non-significant. On the south coast, there was no significant difference in infestation prevalence between species. Endolith-induced mortality rates through shell collapse mirrored the patterns for prevalence. For P. perna, endolith species assemblages revealed clear grouping by bioregions. Our findings indicate that biogeography affects cyanobacteria species composition, but differences between biogeographic regions in their effects are driven by environmental conditions.

Meteorological controls on big waves south of Africa

Meteorological controls on big waves south of Africa in the period 1987–2013 are described. European Community daily climatology since 1987 shows that waves from the SSW off East London at 34S, 27.5E are most frequent in the range 2–4 m and 8–10 s, and pass through a warm pool where heat fluxes amplify air–sea momentum transfer. Time series of 3-hourly Wavewatch v3 swell direction, height and period data at a key point near East London since 1998 provide a basis for analysis, and reveals numerous cases of big SSW wave events during the winter months from May to September. A composite of the six largest cases was made by averaging meteorological fields over a large area south of Africa. The big-wave composite reveals a 975 hPa deep low at 51S, 33E that is slowed by a blocking high in polar latitudes. The highest ranked winter storm case within the time series forms a case study: 24–26 June 2009, and reveals a cold air outbreak producing heat fluxes up to 800 W/m2 under 20 m/s southerly winds in a massive fetch area 35–60S, 15–30E. Swells of 8 m reached the South African coast, damaging infrastructure there.

Observations on the biology and seasonal variation in feeding of the east coast round herring Etrumeus wongratanai (Clupeiformes), off Scottburgh, KwaZulu-Natal, South Africa.

The basic biology and ecology of the South African east coast round herring Etrumeus wongratanai was investigated from samples of fish collected between 2013 and 2016. This species is short-lived and reaches a maximum of 3 years of age, with rapid growth in its first year of life. It reproduces from June to December (austral summer) and condition factor was lowest in May through to August and increased from September, probably reflecting the physiological strain before and during spawning. Fish larvae were the most important food items consumed during summer, whereas eucalanid copepods were the most important prey at other times of the year. Stable-isotope data suggest that there are gradual changes in the trophic level with increasing fish size, δ15 N and δ13 C values also differed between seasons. The results obtained here are compared with those of other Etrumeus species, regionally and globally.

Benthic microalgal variability associated with peritidal stromatolite microhabitats along the South African coast

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 82:253-264 (2019) - DOI: https://doi.org/10.3354/ame01895 Benthic microalgal variability associated with peritidal stromatolite microhabitats along the South African coast Ross-Lynne A. Weston1,*, Renzo Perissinotto1, Gavin M. Rishworth1, Paul-Pierre Steyn2 1DST/NRF Research Chair in Shallow Water Ecosystems, Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Port Elizabeth 6031, South Africa 2Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa *Corresponding author: rosslynne.weston747@gmail.com ABSTRACT: Stromatolites, structures formed with the input of microorganisms such as cyanobacteria, can be traced back to the Precambrian. Many modern marine stromatolites have a coarser internal structure and host a diverse eukaryotic community. Known as eualgal-cyanobacterial stromatolites, these formations are likely a result of the higher abundance of larger sediment particles from the biomineralisation of skeletal material. However, it is unclear how eukaryotic microalgae have contributed towards modern stromatolite formation. Therefore, the aim of this study was to investigate how the microalgal community contributes towards the differences in depth profiles and layering observed amongst mesofabric structures in stromatolite pools along the Port Elizabeth coastline in South Africa. This goal was achieved by comparing the proportional abundances of each of the major microalgal classes (cyanobacteria, bacillariophytes and chlorophytes) between the different mesofabric types and depth profiles. Clear variability in terms of proportional abundance was apparent between microhabitats and with depth. Coarser, irregular types had a higher bacillariophyte biomass than smoother types. This difference is likely a consequence of the greater efficiency of bacillariophytes in trapping larger sediment particles. Eukaryotic microalgae (specifically bacillariophytes) are highlighted as important ecosystem engineers in these modern ecosystems. KEY WORDS: Microbialites · Mesofabric types · Niches · Microphytobenthos · Ecosystem engineering Full text in pdf format Supplementary material PreviousNextCite this article as: Weston RLA, Perissinotto R, Rishworth GM, Steyn PP (2019) Benthic microalgal variability associated with peritidal stromatolite microhabitats along the South African coast. Aquat Microb Ecol 82:253-264. https://doi.org/10.3354/ame01895 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 82, No. 3. Online publication date: January 21, 2019 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2019 Inter-Research.

Stoichiometric multitrophic networks reveal significance of land-sea interaction to ecosystem function in a subtropical nutrient-poor bight, South Africa.

Nearshore marine ecosystems can benefit from their interaction with adjacent ecosystems, especially if they alleviate nutrient limitations in nutrient poor areas. This was the case in our oligo- to mesotrophic study area, the KwaZulu-Natal Bight on the South African subtropical east coast, which is bordered by the Agulhas current. We built stoichiometric, multitrophic ecosystem networks depicting biomass and material flows of carbon, nitrogen and phosphorus in three subsystems of the bight. The networks were analysed to investigate whether the southern, middle and northern bight function similarly in terms of their productivity, transfer efficiency between trophic levels, material cycling, and nutrient limitations. The middle region of the bight was clearly influenced by nutrient additions from the Thukela River, as it had the highest ecosystem productivity, lower transfer efficiencies and degree of cycling. Most nodes in the networks were limited by phosphorus, followed by nitrogen. The middle region adjacent to the Thukela River showed a lower proportion of P limitation especially in summer. Interestingly, there was a clear distinction in sensitivities to nutrient limitations between lower and higher trophic level organisms. This is a reflection of their discrepant nutrient turnover times that are either higher, or lower, than that of the systems, and which might provide a balance to the system through this antagonistic influence. Furthermore, by tracking the stoichiometry through entire food webs it appeared how important the role of lower trophic level organisms was to regulate stoichiometry to more suitable ratios for higher trophic level requirements. Although we gained good insight into the behaviour of the three subsystems in the KZN Bight and the role of terrestrial influence on their functioning, a merged approach of incorporating data on metabolic constraints derived from experiments could further improve the representativeness of multitrophic stoichiometric ecosystem networks.

Spatial variation in meristic and morphometric characteristics of sardine Sardinops sagax around the coast of southern Africa

Spatial variability in phenotypic characteristics within a fish population may be used to infer the existence of multiple stocks, and knowledge of the population structure of exploited species is important for their sustainable management. In this study we investigated geographic variability in meristic (vertebral count) and morphometric (body shape) characteristics of sardine Sardinops sagax from three southern African regions: Namibia, the South African west coast, and the South African south coast. There were significant regional differences in vertebral counts, with Namibian fish tending to have more vertebrae than South African fish, but with no difference between sardine off the South African west and south coasts. Body shape was characterised using morphometric landmarks, and shape changes were investigated using geometric morphometrics, with influences on fish shape assessed using multivariate regressions. To remove the effects of allometry, the 22 shape variables (represented by Procrustes coordinates) were regressed against fish size (represented by centroid size). There was a significant allometric effect, which was removed by using the residuals of these regressions in further analyses. A multivariate multiple regression was applied to the 22 size-corrected shape variables and to three covariates: condition factor, stomach fullness and fat stage. The significant influence of these covariates was removed by using the residuals from this regression in a canonical variate analysis, where corrected shape variables were classified in relation to region, year and sex. The Mahalanobis distances from the canonical variate analysis differed significantly for most combinations of classifier variables, with clear separations among the three regions. Sardinops sagax off Namibia had thicker bodies and more contracted tail regions than South African fish, whereas S. sagax off the South African south coast had thinner bodies and smaller heads than those off the west coast. These results support the hypothesis of multiple sardine stocks around southern Africa.

The influence of different types of granite on indoor radon concentrations of dwellings in the South African West Coast Peninsula

ABSTRACTGranite commonly contains high concentrations of uranium, with subsequent high exhalation of radon gas. The geology of the West Coast Peninsula of South Africa is dominated by granite. No m...

Macroinvertebrate variability between microhabitats of peritidal stromatolites along the South African coast

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 605:37-47 (2018) - DOI: https://doi.org/10.3354/meps12741 Macroinvertebrate variability between microhabitats of peritidal stromatolites along the South African coast Ross-Lynne A. Weston1,*, Renzo Perissinotto1, Gavin M. Rishworth1, Paul-Pierre Steyn2 1DST/NRF Research Chair in Shallow Water Ecosystems, and 2Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa *Corresponding author: rosslynne.weston747@gmail.com ABSTRACT: Along the coastline near Port Elizabeth, South Africa, actively accreting peritidal stromatolite systems host a persistent metazoan community, which seemingly does not disrupt or consistently graze upon these structures. Macroinvertebrate communities occurring in different microhabitats (or mesofabric types) within this system were compared. This was achieved by identifying and counting the invertebrates found across different mesofabric types at different depth profiles. Mesofabric type was an important predictor of the invertebrate assemblage but was not the primary driver of their distribution. One of the well-laminated mesofabrics had more invertebrates than expected. The seasonal changes observed (such as the greater metazoan abundance observed in colloform mat types in winter compared to the greater metazoan abundance found in rimstone mat types in summer) were attributed to resource availability, specifically macroalgae. These findings are discussed in light of top-down forcing by metazoans on stromatolite microhabitats, and the consequent refugia benefit offered by these structures. KEY WORDS: Peritidal communities · Microbialites · Mesofabric type · Niches · Invertebrates Full text in pdf format Supplementary material PreviousNextCite this article as: Weston RA, Perissinotto R, Rishworth GM, Steyn PP (2018) Macroinvertebrate variability between microhabitats of peritidal stromatolites along the South African coast. Mar Ecol Prog Ser 605:37-47. https://doi.org/10.3354/meps12741 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 605. Online publication date: October 26, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.

Anti-Slave-Trade Law, ‘Liberated Africans’ and the State in the South Atlantic World, c.1839–1852*

From 1807 onwards, bilateral slave-trade treaties stipulated how naval squadrons would rescue slaves from slave ships, and how states should arrange the settlement and apprenticeship of these slaves, to transform them into ‘liberated Africans’. Comparing interactions between the state and liberated Africans at sea along the South African and Brazilian coasts, and in the port towns of Cape Town and Salvador, reveals how the legal status of liberated Africans changed over time. Current scholarship has framed liberated Africans in terms of whether they were attributed rights or suffered re-enslavement, and thus focused on their solidarity through claiming rights, ‘ethnic survivals’ or creolization. Instead, this paper argues anti-slave-trade legislation ascribed to liberated Africans a set of unguaranteed entitlements – promises regarding status and treatment without obligating states to uphold that status or treatment. By focusing on the precise aspects of legislation that operated at each point in the process of anti-slave-trade activity – rescuing slaves from slave ships, transportation to a port, processing through a court, and apprenticeship – this paper unearths how the law came into force in the encounter between state officials and liberated Africans, as part of the complex transition from slavery to free labour.