Post Graduate Programme

Name: Justin Hart

Degree: PhD

Title: Sexual reproductive ecology of scleractinian corals on the high-latitude reefs of South Africa

Supervisor: Prof. Michael Schleyer (ORI)

Status: In progress

Justin Hart

Coral communities along the high-energy east coast reefs of KwaZulu-Natal constitute the southernmost distribution of this fauna in Africa. In contrast to their accretive tropical counterparts, conditions on these high-latitude reefs are marginal for coral growth. In addition, these reefs are exposed to storms which render them susceptible to physical disturbance. The introduction of new coral recruits is thus expected to play a pivotal role in the maintenance and resilience of these reefs, but is relatively understudied. Of further concern is the negative impact that predicted climate change conditions, such as ocean acidification, could have on this important life history stage. 

For my PhD I aim to gain a detailed understanding of the sexual reproductive dynamics of a sensitive and a hardy coral species, Acropora austera and Stylophora pistillata. Furthermore, I will determine how these dynamics differ under present and predicted ocean acidification levels. During fieldwork, colonies will be inspected for the presence of mature eggs, to enable the collection of specimens just before spawning. These specimens will be maintained in the ORI research aquarium to facilitate gamete collection. After fertilization, the gametes will be subjected to different CO2 treatments to investigate the influence of ocean acidification on the development of the larvae, their settlement success, and their post-settlement survival. Additional larvae will be subjected to further experiments to improve our understanding of the larval behaviour of these two species.

This study will provide valuable information into the reproductive dynamics of two key coral species found on high-latitude reefs in South Africa. In addition, it will be the first study to compare the influence of ocean acidification on the reproductive dynamics of both a sensitive and hardy coral species. It will thus contribute to a global understanding of the predicted effects of climate change on coral communities.

Name: Liesel Hein

Degree: MSc

Title: Structural biodiversity of soft sediment macrobenthos of the KZN Bight

Supervisors: Ms. Fiona MacKay (ORI)

Status: In progress

Liesel Hein

The oligotrophic KwaZulu-Natal Bight relies on varying amounts of nutrient inputs from the Thukela River and two main oceanographic features; the St Lucia upwelling and the Durban lee eddy. These inputs may have a significant impact on macrobenthic community’s spatial and temporal structure.

Little is known about the KZN shelf community dynamics and therefore the aim of this project, which is part of a larger multidisciplinary programme, is to examine changes in macrobenthic community biodiversity and population dynamics relative to direct and indirect important process drivers (e.g. the Agulhas Current). Ultimately, we hope to understand the relative importance of the three main nutrient inputs in maintaining ecological function across the Bight.

Three replicate substrate grab samples will be taken at numerous stations within and between the three areas of perceived elevated nutrient input. A CTD cast will be deployed at each station to measure relevant water characteristics. Sediment samples will be cored from each grab replicate for the analysis of sediment characteristics.

Sampling will be done during a “wet” (February) and “dry” (August) season. By means of stereo and compound microscopy techniques, all fauna will be counted and identified to the lowest possible taxonomic level. Community diversity will be determined using metrics such as dominance, species richness, diversity, evenness, etc. to distinguish biodiversity changes over space and time.

Through various multivariate (correlation) and univariate (regression) analyses biodiversity will be presented relative to habitat data. As macrobenthos has a key functional role in marine ecosystems, it is important to understand how these fauna respond to a changing environment.

Name: Stuart Laing

Degree: MSc (Economics)

Title: An economic valuation of the Maputaland coral reefs

Supervisors: Prof. Michael Schleyer (ORI) & Dr Jane Turpie (Anchor Environmental Consultants)

Status: In progress

Stuart Laing

This project’s range is the Maputaland Coral Reef system which extends from Kosi Bay in the north to Leven Point in the south, along the KwaZulu-Natal north coast and forms part of ORI’s Coral Reef Programme.

The project seeks to determine the value of the reef both financially and, as far as possible, ecologically. The result of this process would be that the information and values attained could be used for policy-making and to assist in guiding management decisions.

Stuart has completed a literature review and has commenced conducting questionnaire-based surveys. The data he will gather will comprise direct valuation figures as well as a Travel Cost element to assess the consumer surplus and other contingent valuations. The ecological processes that the coral reefs provide will also be identified and assessed as comprehensively as possible. The values attained will be used to derive the economic value of the Maputaland Coral Reefs.

Name: Brendon Lee

Degree: MSc

Title: The biology and fisheries of king mackerel (Scomberomorus commerson) in the South West Indian Ocean with reference to future management initiatives

Supervisors: Mr Bruce Mann and Prof. Rudy van der Elst

Status: In progress

Brendon Lee

King mackerel or couta/cuda as it is locally known, is one of the most important gamefish to recreational ski-boat fishermen off the KwaZulu-Natal (KZN) coastline. However, while it is primarily targeted as a sport fish in South Africa, a much larger proportion of the catch in other African countries of the South Western Indian Ocean (SWIO) is taken by artisanal and semi-industrial fishery sectors through the use of gill nets, beach seines and linefishing.

The aim of the study is to evaluate the fishery and biology of king mackerel in the SWIO and improve our understanding of the stock status of this species in order to ensure its effective management. The project will focus on six countries within the SWIO region namely South Africa, Mozambique, Tanzania, Kenya, Madagascar and Comoros. This project is being funded through the South West Indian Ocean Fisheries Project (SWIOFP).

Sampling will be undertaken on a monthly basis between April 2011 and March 2012, covering a one year period. In South Africa, the sampling area will include the entire KZN coastline from Port Edward in the south to the Mozambique border in the north. Field-based data will be collected from recreational fisherman by sampling at a number of boat launch sites along the coast. Additionally, samples will be collected at ski-boat fishing and spearfishing tournaments to enable the collection of large quantities of data over a relatively short time period.

It is hoped that by comparing the biology and genetics of king mackerel from various countries in the SWIO, a better understanding will be obtained about the movement patterns and stock integrity of this species. The extent to which this species is shared by SWIO countries is crucial for the development of local, sub-regional and regional management strategies which will help to ensure the future sustainable use of this important species.

Name: Lola Massè

Degree: PhD

Title: Latitudinal variation in reproduction and recruitment of scleractinian corals in the Western Indian Ocean: A comparison of Reunion Island and South African reefs

Supervisors: Prof. Michael Schleyer (ORI) & Dr Pascale Chabanet (IRD)

Status: In progress

Lola Massè

Coral recruitment and sexual reproduction are major processes in the maintenance and development of coral reef ecosystems. In particular, they can ensure recovery and replenishment of coral reefs following disturbance.

These processes are very sensitive to disturbance and recent studies have demonstrated that they may provide a more accurate view of coral population dynamics. Recruitment and reproduction constitute a major part of the coral life cycle and can be divided into numerous steps, including gametogenesis, spawning, fertilisation, settlement, metamorphosis and growth of the juvenile colony. Environmental conditions and local anthropogenic pressures may affect each of these steps, influencing coral reproductive strategy, fecundity, time of spawning, recruitment rate and settlement preference.

Very few studies have investigated coral reproduction and recruitment in the western Indian Ocean and further investigation is needed to ascertain the influence of latitude on these biological processes. In the context of global warming, studies are required to ascertain how corals may survive at high sea temperatures and adapt their reproductive strategy. Marine Protected Areas (MPAs) may help to reduce the risk of extinction of corals in the face of climate change. Their influence on coral recruitment and their importance in reef reseeding and recovery will be tested.

Name: Phanor Montoya-Maya

Degree: PhD Name: Phanor Montoya-Maya

Title: Ecologically relevant genetic connectivity within southeast African Marginal reefs

Supervisors: Prof. Michael Schleyer (ORI) & Dr Angus Macdonald (UKZN)

Status: In progress

Phanor Montoya-Maya

Marginal reefs along the south-eastern African coast, from Bazaruto Island in Mozambique to Leadsman Shoal in South Africa, have drawn the attention of reefs scientists and managers as these coral communities are said to illustrate the future of true, tropical coral reef communities under current trends of climate change. However, limited knowledge on the interdependence of south-east African coral communities in terms of genetic exchange hinders their effective management. Accordingly, coral population genetics of Acropora austera and Platygyra daedalea are being examined to assess the level of contemporary, small-scale connectivity between the reef systems and its significance to reef resilience. This is aimed at improving reef management in the local and regional context.

Comprehensive sampling has been undertaken on Two-mile Reef (TMR), the most heavily-used reef in the region. Reefs to the north and south of TMR were sampled to include potential sources and sinks of coral larvae. Despite the paucity of symbiont-free tissue and genome information to develop coral-specific markers for two coral species of interest, viz. A. austera and Platygyra daedalea, the project has managed to produce several nuclear markers suitable for population genetic analysis. The laboratory work has been completed and, as a result, contemporary genetic connectivity is now being estimated using individual-based methods, namely assignment and spatial autocorrelation analysis.

Preliminary results suggest significant genetic variation between the studied reefs, associated to a pattern of isolation by distance. At the finer scale, there is significant spatial genetic structure for colonies within 10 mts of each other, which suggests either limited dispersal or high levels of self-recruitment in these two species of corals. These estimates of inter- and intra-population connectivity suggest South African reefs are isolated from northern reefs at ecological time scales, which may limit their ability to recover from large-scale damage. If that is the case, a new management strategy may be needed. The importance of making informed management decisions cannot be underestimated if we are to succeed in preserving the genetic biodiversity of our marine resources. Indeed, the outcomes of this study are being used to assess the resilience potential of coral communities in South Africa.

You can read more about my project and other work of my interest in my personal website 

Name: Mathieu Séré

Degree: PhD

Title: Identification and aetiology of diseases associated with Scleractinian corals in the South-West Indian Ocean: Comparative study between South African and Reunion Island Reefs

Supervisors: Prof. Michael Schleyer (ORI) & Dr Jean-Pascal Quod (ARVAM)

Status: In progress

Mathieu Séré

Coral reefs in the western Indian Ocean are among the most productive, diverse and complex ecosystems in the world and support almost one third of the world’s marine fish species. In the western Indian Ocean, approximately thirty million people depend directly or indirectly on the coastal environment for goods and services. However, they are impacted by anthropogenic factors, climate change and natural disturbances. These stresses, acting alone or in synergy, could alter the resistance of corals and stimulate the growth of pathogenic organisms.

During the past two decades, the emergence and spread of infectious diseases have caused substantial declines in the biodiversity and abundance of reef-building corals. These diseases are known to generate a progressive tissue loss and affect the coral growth rate, reproductive capacity, recruitment, species diversity, and abundance of reef-associated organisms.

Thus, it is urgent that these diseases are understood, including the mechanisms underlying the host–pathogen interactions and the synergistic roles of abiotic stressors, to predict and mitigate disease outbreaks. To date, no attempts have been made to identify infectious diseases and determine their prevalence and aetiology on the western Indian Ocean coral reefs. Thus this PhD project will address this gap in knowledge by providing data on 1) the epizoology of coral diseases, and 2) the identification and characterization of the pathogenic agents using field observation combined with techniques from microbiology.

Name: Candice Untiedt

Degree: MSc

Title: Structural dynamics and changes in macrobenthic trophic communities within and between three areas of the Natal Bight

Supervisors: Ms. Fiona MacKay (ORI)

Status: In progress

Candice Untiedt

This project is part of a larger programme investigating Natal Bight ecosystem functioning, under the African Coelacanth Ecosystem Programme (ACEP).

The main hypothesis of the Natal Bight project is that nutrients that are either land derived (Thukela River) or from local oceanographic features (St Lucia upwelling, Durban lee eddy), drive the structure and functioning of biological communities on the Natal Bight.

This macrobenthic project will contribute to our understanding of the Natal Bight ecosystem by investigating the relationship between seafloor habitat and macrobenthic trophic guilds in three focus areas of the Natal Bight. Mooring and CTD data will be used to understand how hydrodynamic agents shape the benthic habitat and in turn determine macrobenthic community structure.

It is hypothesised that macrobenthic trophic guild abundance and spatial distribution will be different within and between the three focus areas. Transects set along different sediment distribution and depth related gradients will be sampled during a wet (February 2010) and a dry (August 2010) season to determine changes in communities in space and time.

Three replicate samples will be collected at each station with a van Veen grab (0.2m2), each being sub-sampled for sedimentary analysis and the remainder washed through a 1000µm sieve. Samples will be sorted, macrobenthic fauna identified and enumerated. Each species will then be assigned to a trophic guild and the wet biomass of each trophic guild determined. Habitat parameters (real measurements and proxies of the local hydrodynamic regime) will then be linked to macrobenthic trophic guilds to explain biomass and distribution patterns.

Name: Alan Foulis

Degree: MSc

Title: A retrospective analysis of shark catches made by pelagic longliners off the east coast of South Africa and biology and life history of shortfin mako shark, Isurus oxyrinchus.

Supervisors: Prof. J. Groeneveld (ORI), Dr. S. Dudley (KZNSB), Dr D. Glassom (UKZN)

Status: In progress

Declining bycatch of pelagic sharks in longline fisheries for tunas and swordfish has raised concerns that shark populations may be under pressure from these fisheries in the South West Indian Ocean (SWIO) region. Historical data on shark catches collected by fisheries observers on commercial longliners over the past 10 years, and official shark landing statistics were analyzed to investigate trends in fishing effort, catch and catch rate over time, relative to fishing area, season, and fishing fleet. A generalized linear modeling framework was used to standardize catch rates to provide an indication of the status of shark populations. Shortfin mako sharks (Isurus oxyrinchus) were sampled for length, sex, body weight, vertebrae for ageing studies and reproductive maturity during field trips on a shark-directed longliner operating on the Agulhas Bank, and additional data on mako sharks were obtained from specimens collected from the shark nets set off the KZN coastline. These data were used to investigate the distribution, abundance and size composition of mako shark populations, and to  assess age and growth, size at maturity and reproductive behaviour. The thesis provides important information on the status of pelagic shark populations off eastern South Africa, and provides biological and life history parameters that can be used for fisheries management strategies.

Name: Stephanie Hayman

Degree: MSc

Title: Past and present effects of ocean acidification on a South African coral reef and associated bioclastic sediment.

Supervisors: Prof Michael Schleyer (ORI), Ms Fiona MacKay (ORI) & Dr Andrew Green (UKZN)

Status: In progress

Stephanie Hayman

Coral reefs have a high species diversity and serve as measures to track climate change. Sodwana Bay’s coral reefs are experiencing change due to climate change and as calcifying marine organisms have survived past climate changes, they provide valuable insight into these events. Palaeo-environmental records can be extracted from these organisms and the nature of these changes monitored and used as a comparison in assessing present day conditions.

The main aim of the study will be to ascertain the influence climate change and subsequently ocean acidification has had on two calcifying marine organisms, namely benthic forams and corals. Benthic foraminiferal assemblages are used as bioindicators for global-change events within the geological record as they have short life cycles, are sensitive to environmental conditions and they react quicker to water quality changes in comparison to corals. Porites lutea corals serve as archives, preserving a chronology of environmental events within their skeletons, providing information on SST, the salinity, anthropogenic effects, river input and rainfall of the region.

A coral core of Porites lutea will be collected off Two-Mile Reef at Sodwana Bay as well as three cores of the adjacent bioclastic sediment and these will be analysed. The research aquarium will be utilized to simulate various acidification levels and the subsequent calcium carbonate saturation states. The effects of this, on calcification and growth in both corals and forams, will then be measured for both present day and future conditions. Through the incorporation of this multidisciplinary research, the aim is to gain a more comprehensive understanding of the relationship between anthropogenically produced CO2 and the resultant consequences for the marine calcifiers.

This master’s thesis falls within the framework of the ACCESS programme, theme 7.

Name: Maggie Reddy

Degree: PhD

Title: Molecular phylogeny, phylogeography and population genetic structure of a shallow-water spiny lobster Panulirus homarus in the South West Indian Ocean.

Supervisors: Prof. Johan Groeneveld, Prof. Mike Schleyer, Dr Angus Macdonald

Status: In progress

Maggie completed an MSc degree on the molecular phylogeny and population genetic structure of shallow-water spiny lobster Panulirus homarus, as part of the regional South West Indian Ocean Fisheries Project (SWIOFP).

Her project included sampling sites in eastern South Africa and Mozambique, and genetic analyses showed that two subspecies of P. homarus (P.h. rubellus and P.h homarus) are genetically distinct clades that differ by 2-3%. Populations of P. homarus rubellus were genetically structured along the coast.

Maggie registered for a PhD at the University of KwaZulu-Natal in 2013, and her project expands on the results from her MSc. The PhD project will include microsatellite markers for finer scale analyses, and address a much larger geographical area, by including sites from Madagascar and along the East African coast, northwards to Oman.

A novel aspect of the study is that it will use the genetic signatures from both adult and drifting phyllosoma larvae to elucidate larval dispersal pathways. Phyllosomas have a long larval life and are dispersed far offshore by ocean currents, before returning to the shore and settling on the seafloor to begin a benthic existence. The phyllosoma larvae will be collected with plankton nets from research vessels operating in the Western Indian Ocean.