Postgraduate Research Students
“Investigating the influence of shading in bleaching events”
Supervisors: Dr Daniel Harrison and Associate Professor Kai Schulz
The Great Barrier Reef (GBR) represents significant ecological importance and is of deep cultural value. Interventions have been developed to ameliorate further bleaching damage. Marine cloud brightening and fogging techniques that focus on the environmental adjustment of shading and cooling, may be applied for reducing sea surface temperatures and reducing incoming incident solar radiation in localized regions. Hydrodynamic-biogeochemical models have been developed to simulate the benefits of cooling and shading. Expanding on these models, I will be using the coral sub-model from eReefs to create scenarios that will be informative for future bleaching events and the application of shading interventions on the GBR. Secondary information will include the importance of shading from tropical weather systems and which meteorological processes are most conducive to reducing the severity of bleaching. An important aspect of this project will be the development of the coral sub-model, to better model bleaching as a function of temperature and light. Reactive oxygen species are intracellular messengers produced during oxidative stress and will be used as a proxy of bleaching in this project.
“Indigenous ecological knowledge in fisheries research: an assessment of pipi and associated biotoxins and parasites in NSW, Australia”
Supervisors: Dr Anna Scott and Dr Karina Hall (NSW DPI)
The value of Indigenous ecological knowledge (IEK) in providing essential information for fisheries research is gaining momentum as many global fisheries continue to decline to unsustainable levels. Contemporary cultural catch and use data, combined with historical baseline information provided by IEK, can complement conventional scientific knowledge. More importantly, the involvement of traditional owners in fisheries research fosters co-management and the stewardship of resources. My project aims to develop a fully integrated fisheries traditional owner participatory research project whilst assessing a cultural keystone species, pipi and associated biotoxins within three Aboriginal nations on the mid-north coast of NSW, Australia. Historical and contemporary changes to distribution and abundance will be assessed, along with the uptake and depuration of biotoxins in pipi and IEK food safety treatments. This information will support the sustainable and safe use of pipi across fishing sectors and support the protection of a cultural keystone species vital for the maintenance of IEK.
“Investigating the use of coral fogging as a mass bleaching intervention tool”
Supervisors: Professor Brendan Kelaher and Dr Daniel Harrison
The success of coral reef preservation efforts in the coming decades will depend on the application of active conservation solutions at the reef level and a steadfast commitment to global emission reductions. The primary aim of my PhD is to evaluate the potential of seawater-based fogging as an active intervention method to ameliorate bleaching stress in coral. This study will use tank based simulated bleaching experiments to conduct the first laboratory tests of marine fogging on corals and fill knowledge gaps related to the feasibility of larger scale fogging efforts and species-specific changes in bleaching vulnerability.
“Characterisation and dispersion of sea salt particle emissions for Marine Cloud Brightening over the Great Barrier Reef”
Supervisors: Dr Daniel Harrison and Professor Brendan Kelaher
The implementation of Marine Cloud Brightening could potentially reduce coral bleaching risk by generating a cooling effect on the sea surface as a result of the increase in reflectance of low-level maritime clouds. My research aims to characterise the dispersion and evolution of a plume of micrometre to sub-micrometre sized seawater droplets, which are emitted from a sprayer operating over the Great Barrier Reef to examine the effectiveness of the Marine Cloud Brightening concept. Furthermore, my research investigates how the variability of atmospheric conditions during the summer season affects the behaviour of the plume over the reef. The ultimate goal is to develop the capacity to predict the portion of released sea salt particles that are incorporated into low lying cloud. This study will fill knowledge gaps concerning dispersion of aerosols over the reef and the effects of negative buoyancy on the vertical mixing of plumes. It will also contribute to the general understanding of cloud brightening and its feasibility to be implemented over the GBR to prevent coral bleaching in future climates.
Nathaniel (Nate) Hess
“Investigating the influence of shading in bleaching events”
Supervisors: Professor Kirsten Benkendorff and Professor Christian Sanders
Nate is originally from Arlington, Virginia. He went to college at the University of Puget Sound in Tacoma, Washington, where he received a B.S. in Biology with a minor in theatre. During his time there, he conducted ecological research on the spatial distribution of Vaccinium spp. (Huckleberries, Blueberries, Cranberries) in relation to Tsuga heterophylla (Western Hemlock) and soil pH, as well as spatial and temporal factors influencing Saccostrea glomeratta (Sydney Rock Oyster) feeding behavior. He completed his Honours at the University of Sydney, where he received 1st class distinction for his project “Linking Temporal and Spatial Changes in Water Quality to Oyster Aquaculture using Novel Remote Sensing Approaches.” Continuing his love for oysters, he is conducting his PhD on the Water and Sediment quality Remediation potential of oyster aquaculture. Nate is also an Advanced Open Water SCUBA diver working on his rescue diver certification and is an accomplished Ultimate Frisbee player who has qualified for USA College Nationals and placed 3rd at the Australian University Mixed Ultimate Championships with Sydney Uni.
Muhammad M. Islami
“Post-flood recovery and impacts of flood-related stressors on benthic fauna in estuaries of the North-Mid North coast NSW”
Supervisors: Professor Kirsten Benkendorff, Dr. Victoria Cole (NSW DPI) and Professor Stephen Smith
Estuaries, essential for nutrient cycling and ecosystem productivity, frequently receive enormous nutrient inputs from anthropogenic activities and agricultural discharges, typically followed by severe eutrophication events. In addition, natural perturbations, such as flooding, can adversely impact estuarine systems and alter macrobenthic communities. Although they are very important for estuarine systems, benthic invertebrates are rarely considered in flood impact studies, which focus on larger organisms. In my PhD, I will investigate spatio-temporal variability of macrobenthic diversity, explore environmental drivers for benthic community change, and assess the synergistic effects of low salinity and other flood-related stressors on benthic invertebrate indicators. These findings will contribute to evaluating the health and productivity of estuarine systems following flood events and improve knowledge of the impacts of crucial stressors on benthic invertebrates that provide a critical component of estuarine food webs.
“The feasibility of shellfish reef restoration with the leaf oyster (Isognomon ephippium).”
Supervisors: Professor Kirsten Benkendorff, and co-supervised by Victoria Cole (NSW DPI)
Oyster reefs create complex, three-dimensional habitats in coastal environments which support diverse marine species and provide ecosystem services. However, oyster reefs have declined in the last two centuries by more than 85% globally due to a range of primarily anthropogenic factors. Chris’s PhD focuses on investigating the feasibility of using the native leaf oyster, Isognomon ephippium, in shellfish reef restoration. This involves studying the life history and reproductive biology of leaf oysters to inform future conservation efforts and restoration guidelines in Australia. He will also investigate ecosystem services provided by leaf oyster reefs, such as water filtration and denitrification.
“The biology, ecology, and conservation of the Endangered soft coral Dendronephthya australis”
Supervisors: Prof. Kirsten Benkendorff, Prof. Stephen Smith, Dr. David Harasti, and Dr. Tom Davis
I am investigating the decline of the rare soft coral species Dendronephthya australis in the Port Stephens estuary, and am gaining a better understanding of its biology and ecology. Ultimately, I aim to identify potential conservation measures that can be employed to aid the recovery of this unique and ecologically important species.
“The role of predation in population eruptions of Crown of Thorns Starfish (Acanthaster sp.)”
Supervisor: Professor Symon Dworjanyn
Corals are under pressure from both anthropogenic and natural stressors. As a result, coral reefs are degrading globally. One major issue impacting coral reefs is population eruptions of the coral-eating Crown-of-Thorns Starfish (CoTS). A key knowledge gap in our understanding of CoTS population dynamics is the factors that determine the transition from herbivory to corallivory. My PhD is aimed at examining how changes in coral reefs (e.g. decrease coral cover, increased seaweed cover, and warming) influence the onset of corallivory by juvenile CoTS.
“The trophic and nutritional ecology of an apex predator, the white shark (Carcharodon carcharias) in eastern Australian waters”
Supervisors: Dr Anna Scott and Dr Paul Butcher (NSW DPI)
White sharks play a crucial ecological role by shaping their ecosystem through trophic relationships. My project will examine the diet and nutritional condition of white sharks through biochemical tracer and metabolite analysis. It will elucidate factors influencing their foraging and habitat use and provide crucial information to manage and conserve this vulnerable species.
“The influence of ocean climate change and single-use plastics on estuarine ecosystem processes”
Supervisors: Professor Brendan Kelaher and Associate Professor Kai Schulz
My research aims to assess whether ocean warming, acidification, single-use plastics, and their interactions, have an impact on estuarine ecosystem processes. Particularly, I’m investigating the impacts these have on seagrass decomposition and microphytobenthic activity which are key components of the trophic structure and nutrient cycle in estuaries. Evaluating the responses to these factors may assist in the development of future management strategies for maintaining these key processes in estuaries.
“Evolutionary potential of Platygyra daedalea to adapt to climate warming”
Supervisors: Dr Emily Howells and Ramil Mauleon (King Abdullah University of Science and Technology in Saudi Arabia)
Rising sea temperatures caused by climate change are threatening the survival of coral reef ecosystems around the globe. Some predictions project severe bleaching events for 99 % of the world’s coral reefs within the 21st century. For my master’s thesis I spent one year in Saudi Arabia, trying to identify genetic polymorphisms associated with heat tolerance in corals from the Arabian Peninsula, where corals possess the highest known bleaching thresholds. Now I continue my work in Australia, but still in collaboration with the King Abdullah University of Science and Technology in Saudi Arabia, and my research aims to determine whether coral populations have the potential for genetic adaptation to climate warming. Expected outcomes include new information on the genetic basis for thermal tolerance across coral life stages, standing genetic variation within populations, and the distribution of heat tolerant variants among reefs.
“Identifying genetic markers for key coral traits of Acropora hyacinthus using whole genome sequencing”
Supervisors: Dr. Emily Howells, Dr. Line Bay, and Dr. Ramil Mauleon
Global mass bleaching events present a bleak future for coral reefs, with predictions of major declines worldwide. However, some corals are better able to tolerate heat stress, likely due in part to genetic differences. These genetic differences may correlate with phenotypic variation in key traits such as endosymbiont photosynthetic efficiency and spectral signatures of metabolomics. It is important to assess this variation to understand which coral genotypes have the best chance of persisting in a warming future. It is not yet known how much variation in these traits exists across large scales, such as the Great Barrier Reef (GBR), and few genetic markers exist to predict heat tolerance in corals. In my PhD, I will be assessing variation of key traits in Acropora hyacinthus across the GBR and performing a Genome Wide Association Study (GWAS) to identify genetic markers that correlate with those traits. These research outcomes will assist conservation programs in selecting optimal genotypes for selective breeding and assisted gene flow programs.
“Fishery biology and ecology of the marine snail, Turbo militaris”
Supervisors: Professor Kirsten Benkendorff, and co-supervised by Assoc Prof Steve Purcell, Prof Steve Smith and Dr Hamish Malcolm (NSW DPI)
Turbinids are among the most sought-after marine gastropods harvested on rocky shores, targeted for their high-quality meat and nacreous shell. The large turbinid, Turbo militaris is endemic to the Australian east coast and is collected recreationally, commercially and culturally. Despite heavy harvesting, there is little known about this species. The objective of this thesis is to address critical knowledge gaps on the biology and ecology of T. militaris. This project will elevate our knowledge of this species and provide useful information for fisheries management decisions. Additionally, this thesis will offer broader insights into the spatial variability of turbinids' biological and ecological processes across a latitudinal gradient. Overall, by developing the knowledge-base for T. militaris, this research will aid in facilitating the transition of this species from data-deficient to scientifically managed.
“Effects of climate change on economically important fish species in temperate Australia”
Supervisors: Professor Kirsten Benkendorff, and collaboratively co-supervised by DPI staff Prof Melinda Coleman and Dr Curtis Champion
The effects of climate change on marine ecosystems are driving unprecedented biological responses and challenging our use of marine resources in the future. Species’ physiological responses to climate change can impact their nutritional quality and therefore human nutritional health. Billions of people globally depend on seafood as a primary source of protein and essential micronutrients, and this reliance is predicted to increase with continued population growth. Despite the potential for environmental change to affect the physiology of harvested marine resources, the effects of climate change on the nutritional quality of seafood remains poorly understood. This project will quantify and describe the effects of climate change on the health and nutritional quality of key harvested species across the marine food web. The response of seafood health and nutritional properties to climate-driven environmental change in conjunction with the effects on species mortality, growth and distribution will be used to determine implications for future food security and human health. These findings will contribute to an emerging understanding of the resilience and vulnerability of harvested marine species to changing environmental conditions, with implications for the future sustainability and nutritional quality of seafood.
"Investigating climate change impacts to fisheries on the east coast of Australia"
Supervisors: Professor Brendan Kelaher and Karina Hall (NSW DPI)
I will be investigating the impact of increased temperature and carbon dioxide levels on two important fisheries species; Eastern School Whiting (Sillago flindersi) and Stout Whiting (Sillago robusta). Fish will be subjected to predicted climate change scenarios within a mesocosm experiment at the NMSC, to investigate potential variation in growth rates, condition and determine the thermal dependency of oxygen isotopes in fish otoliths. Results from this project will inform fisheries management practices within state and federal jurisdictions on the east coast of Australia.
“Assessing vulnerability of key marine habitats to climate change”
Supervisors: Prof Symon Dworjanyn, Dr Melinda Coleman (Adjunct Professor – NMSC) and Dr Curtis Champion (Adjunct Lecturer – NMSC)
Reina joins us from the Netherlands, after completing her MSc in Ireland. She'll be doing her PhD on effects of climate change on benthic habitats, specifically kelp gametophytes. Reina is a co-funded SCU/DPI student
“Phenotypic signatures of temperature tolerance in corals on the Great Barrier Reef ”
Supervisors: Dr. Emily Howells, Dr. Anna Scott, Dr. Line Bay (AIMS), Dr. Samantha Goyen (AIMS)
Increasing frequency and intensity or warm water thermal anomalies are causing widespread coral bleaching from heat stress. These anomalies can affect some areas more than others as reef systems exhibit complex spatial-temporal heterogeneity resulting in corals with variable thermal histories. In my PhD, I will seek to find common phenotypic signatures of temperature tolerance and thermal plasticity across species, populations, and reefs on the Great Barrier Reef. I will use rapid heat stress assays to elicit a variable bleaching response to examine relationships between physiological phenotypic characteristics and the underlying genetic makeup of the coral holobionts to advance our understanding of their adaptive capacity. Overall, results from this research can inform conservation and restoration efforts globally and will provide data critical to predictive models of coral adaptation and resilience under environmental change.