We have many exciting PhD projects already approved in our QAS, QMS and RHD programs.
If you don't see something that fits your interest or passion, please explore our find a supervisor tool, and get in touch with a supervisor who may be able to help you.
Dr Patti Virtue (supervision contact)
Dr Olav Rune Godø (Institute of Marine Research, Norway)
Dr Peter Nichols (CSIRO)
Funding for a PhD student scholarship has been obtained through an ARC Linkage grant. This research will be done jointly through the IMAS and Institute of Marine Research, Norway. Antarctic krill are an important species in the Southern Ocean supporting most of the Antarctic birds and mammals. A sustainable krill fishery is developing with krill products used in aquaculture and increasingly for human consumption. A new omega 3 krill oil industry has emerged and is rapidly expanding. Our aim is to understand and predict the factors governing oil levels and the biochemical composition in krill in an ecological perspective, including impacts of distribution, growth, reproduction and recruitment.
The scientific elements of this PhD will include:
1. Experimental work over four seasons to investigate how the acoustic characteristics of krill are affected by oil content, maturation status, and behavioural characteristics
2. Investigation of the relative contribution of krill oil levels, krill shape sex and size to their acoustic characteristics
3. Investigation of krill distribution and stratification in the Antarctic over four seasons in relation to the conclusions from item 1 and in relation to krill lipid studies
There is a possibility that the student will join a krill acoustic survey team this summer (January 2016) to Antarctica aboard the RS James Clark Ross.
The PhD student will be involved in collecting acoustic and biological data during commercial fishing and scientific surveying of krill. The student will receive training in acoustics which will be the main tool for mapping krill density distributions in space and time. Uncovering acoustic backscattering properties of krill throughout their life cycle will be done in controlled laboratory experiments as well as through in situ observation, with an emphasis on utilising the potential of broadband acoustic techniques. The student will work together with two other PhD students in the project to link acoustic properties and behavioural characteristics to the observed variation in lipid contents or other physiological and biochemistry properties of the krill. The students will have access to krill experimental facilities and various sophisticated acoustic field equipment.
The PhD student will be based at the Institute of Marine Research (IMR) in Bergen, Norway and IMAS. They will be supervised by a research team as part of the ARC Linkage. The student will spend time in Bergen and Hobart and take courses both at University of Bergen and at UTAS.
Skills needed selection criteria of candidates:
First Class Honours (or equivalent) or Master's degree in a relevant discipline (eg physics, statistics, cybernetics and biological sciences). Some basic knowledge in acoustics is desirable, and an interest to develop and apply acoustic technology to address biological questions. Ability to work at sea as part of an interdisciplinary team. Strong written and oral communication skills.
Dr Steve Rintoul
In this project, we will gather together a range of observations that have been collected in the ACC south of Tasmania over the last two decades. This location is upstream of the Macquarie Ridge where the SAF meanders strongly, and eddy activity is high. TNG14 examine this region in the OFES model and find that the meander flexing process is active there. We will synthesize existing observations to build a detailed description of the 3-dimensional structure of a meander, and quantify the processes that contribute to the vertical transfer of momentum, and poleward flux of heat. We will use complementary satellite and Argo observations, a time-varying climatology, and model simulations to investigate the response of the meander to changing winds and surface fluxes.
The supervisors have just received ARC funding (DP170102162) to make new fine resolution observations of the Macquarie meander. This PhD project will provide valuable analysis of existing observations to guide the new work. The PhD student will participate in the research voyage and contribute to analysis of the new observations from the ARC project.
Dr Stuart Corney (supervision contact)
Dr Sophie Bestley
Krill play a central role in Southern Ocean foodwebs, and have a unique life cycle that utilises fundamentally different habitats at different life stages. This project will use biophysical modelling approaches to model krill habitat use at larval, juvenile and adult stages and to explore interactions with krill predators. The project will use output from a sea ice model and expand upon a set of recently developed algorithms to identify key areas for under-ice larval krill habitat, based on both food availability and habitat complexity. Transport modelling approaches will then be used to identify key locations for recruitment of juvenile krill to the adult population, and to relate these to large-scale patterns of krill flux, focusing in particular on the Indian Sector of the Southern Ocean. Evaluation and interpretation of these spatio-temporal predictions may utilise both ship-based observations of Antarctic marine predators (whales and flying seabirds) as well as available electronic tracking datasets (seals and penguins). These models will be used to evaluate potential responses of krill populations under IPCC climate change scenarios, and the associated implications for krill-dependent predators. Here there may also be scope to develop specific habitat suitability models for key CCAMLR indicator species such as Adelie penguins. Modelling approaches to represent habitat use by larval, juvenile and adult krill will help to inform our understanding of krill population responses to environmental change. These models will also contribute to informing management of the Southern Ocean krill fishery, and to interpreting interactions between krill prey and their dependent predators.
Dr Zanna Chase (supervision contact)
The long-lived naturally-occurring radionuclides, 231Pa and 230Th, are used in paleoceanography to reconstruct particle flux (productivity) and circulation, two key components of the climate system. Yet our understanding of the behaviour of these isotopes in the modern ocean is incomplete. To increase understanding of these and other elements, the international community launched GEOTRACES, a comprehensive study of the oceanic cycling and distribution of trace elements and their isotopes. The Australian GEOTRACES leg in the South West Pacific forms the basis of this PhD project. Additional samples may be collected in the Southern Ocean as opportunities arise. These measurements will be used to inform pale-reconstructions of productivity and circulation in the region from marine sediment cores. Measurements of 231Pa and 230Th will be made by isotope dilution ICP-MS.
Philip Boyd (IMAS, ACE CRC)
Andrew McMinn (IMAS, ACE CRC)
The project will use a combination of lab-based experimental chambers and field-based (shipboard) incubators to investigate the interplay between different tropic levels within the microbial foodweb. The following will be measured: uptake of DOC and bacterial secondary production, grazing on heterotrophic bacteria by a range of different microzooplankton grazers. This will enable the flows of energy to be estimated through the microbial foodweb. A parallel suite of rate measurements will be conducted to determine patterns of nutrient recycling by the microbes. The findings of this research will link with ecological modelling experiments to place the altered role of the microbial foodweb into a wider ecological context.
(One other co-supervisor to be appointed with expertise in bio-optics and ocean remote sensing)
The tropical Pacific spans a quarter of Earth’s circumference and is the origin of the most globally influential mode
of climate variability: El Nino. Under normal conditions, upwelling leads to moderate productivity but also a large flux of CO2 to the atmosphere. During El Nino, upwelling, productivity and CO2 flux can be weakened or shut down entirely.
It is important that we understand not only the total variability in tropical Pacific primary productivity, but also the changes in phytoplankton community composition. These changes have consequences for the food web, and for export of carbon to depth.
This project would suit someone with an interest in large scale ocean variability at time scales spanning seasons to decades. The student will use a combination of the following data sets to understand changes in the tropical Pacific ecosystem:
There is also scope to develop regionally-tuned satellite algorithms.The goal of the project is to develop a more detailed understanding of the relationship between large scale climate modes and ecosystem function, including future changes.
Professor Richard Coleman (supervision contact)
Dr John Hunter (CSIRO)
Dr John Church (CSIRO)
Global average sea level rose 10-20 cm over the past century and could rise as much as 80 cm during the present century, due primarily to global warming (from the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), 2001). While we are quite confident about the historic rate of rise of global sea level, we know little about the regional variation of that rise, especially in the Southern Hemisphere where there is a dearth of observational data. We also know little about changes in extreme sea level heights (e.g. due to storm surges) during the last century. It is, however, important that we understand what happened in the last century if we are to predict what will happen during the present century.
There exists, both in Australia and overseas, a large and relatively unexplored data set, originating from coastal tide gauges. However, many of these data sets are not presently referenced to standard vertical height datums, some contain errors (which are, in many cases, correctable), and a significant number are not yet in digital form. This represents a considerable problem of resource allocation, in the sense that there will probably never be sufficient resources to satisfactorily analyse all existing tide gauge records. We therefore have to select the most appropriate historic records (i.e. those that will provide useful data in a required region, and for which there is a reasonable chance that reliable datum information will be found).
Over the past decade, sea-level height has also been monitored by a number of orbiting satellites, using radar altimeters. The near-global coverage allows us to make good estimates of global sea-level rise, although the limited time-span precludes estimation of sea-level rise prior to about 1990. A recent analysis by researchers from the ACE CRC has used the satellite data to infer the spatial variability of sea level rise, and the tide gauge data to infer the time history. Such a combination of tide gauge and satellite data has yielded a reconstruction of sea level at high spatial resolution over the globe, covering much of the 20th century.
We are therefore gaining a quite good understanding of the way in which sea level varied during the 20th century. We do, however, have a significant problem in accounting for the observed rise in terms of the water budget and thermal expansion. For example, the IPCC Third Assessment Report could only account for around one half of the observed sea level rise. There is therefore a concerted international effort to improve our understanding of the various contributions to the observed sea level rise.
The project would seek to both quantify and understand one or more of the aspects of historic sea level rise noted above. Possible projects would include:
The analysis of the results of numerical models of the ocean/atmosphere system in order to improve our understanding of various contributions to sea level rise.
Dr Alan Henderson
Dr Tim Gale
A/Prof Greg Smith
Spiny lobsters are one of the world’s most valuable seafood commodities making them an attractive candidate for aquaculture. They have many favourable biological features, however to date commercial scale aquaculture has not been possible due to major bottlenecks during the larval phase of development. The student will join a team of researchers working in the ARC Research Hub for Commercial Development of Rock Lobster Culture Systems; a world class facility in Tasmania. Project supervision will be provided by leading experts from the Institute for Marine and Antarctic Studies and the UTAS School of Engineering & ICT.
The PhD project will develop hardware and software for capturing, processing and analysing images and then apply it to interpret and determine key elements of lobster larval (phyllosoma) morphology and physiology.
The process of image recognition for phyllosoma will be a challenging goal as phyllosoma are small (1.5 – 30 mm, total length) and transparent with minimal body thickness. Key phyllosoma features such as eyes, antennas, legs and body are discernible, however the orientation and position of the animals and limbs will vary in water. The rapid assessment and documentation of stage specific morphological characteristics associated with the complex larval life-history has never before been studied in such detail. The technology will be applied to identify feed ingestion during culture and experimentally, the duration to satiation, optimising feeding regimes, health monitoring, moult events, and pre-metamorphosis phyllosoma.
FRDC has approved a three-year, $900,000 project to assess the impact of sediments from Tasmanian salmon farms on adjacent or nearby rocky reef systems and the potential for interactions with other marine industries. The study will provide information to help managers provide for the sustainability and future expansion of fish farming, and will describe existing impacts on other commercial and recreational users.
For many months now commercial and recreational fishers and farmers have complained publicly about sediments, referred to as dust, which they believe have come from salmon farms impacting important productive reef systems in southern Tasmania. Tasmania's coastal reef systems support significant fisheries for a range of species that include trumpeters, morwongs, wrasse, rock lobster and abalone.
A key concern is whether there may be adverse effects on reef health (i.e. off-site interactions) as a result of increased aquaculture activities. Therefore a key element of the main FRDC study will be to provide a better assessment of the potential risk to reef systems from sediment deposition and nutrient dispersion from fish farms directly. Whilst the study will use modelling to predict the risk associated with the deposition of farm derived sediments to the ecology of reef habitats in new farming regions, and will seek to identify cost-effective and risk appropriate approaches for assessment of reef health, it is not within the scope of the study to evaluate effects on abalone directly. Consequently, this PhD project is proposed in association with the main study to provide a better understanding using biomarker accumulation rates of how waste feed/ faeces from salmon farming might directly influence abalone, and to what extent abalone might take up nutrients resulting from fish farming. The study will also compare these laboratory derived accumulation rates with loadings in fish collected from the wild (FRDC study areas) to assess natural loadings and the influence of trophic interactions.
Dr Neville Barrett (supervision contact)
Dr Keith Hayes
Dr Scott Foster (CSIRO)
With the development of a new Commonwealth MPA network in Australian coastal waters, comes the need to provide adequate inventories of the species represented within this network, and to monitor the biological values through time to determine the extent of protection-related changes, to identify potential threats and to understand the implications of future climate change. Despite this need, we currently know very little about patterns of biodiversity in Australian waters at depths below those able to be adequately surveyed by SCUBA-dive based techniques. As much of the Commonwealth MPA estate is in this deeper category, new, non-intrusive approaches need to be examined to address this gap. Video, or still-camera approaches appear to be best placed to meet this need, however, there are a range of possible platforms by which this may be undertaken and all need to be adequately evaluated for their relative performance in this task. Some of these tools are in early stages of evaluation in this space, including Baited Underwater Video (BUVs), Autonomous Underwater Vehicles (AUVs) and towed video, and all have their own strengths and weaknesses. ROVs are the least evaluated, yet have a number of strengths that could make them essential tools in future deep-water biological surveys once they are adequately assessed. These strengths include the ability to be driven along fixed and repeatable transects, to target particular seabed features at fine scale (following the track of the vehicle over base-maps), to deploy high resolution video (forward and downward looking) and carry high resolution still cameras as extra payload. This combination of tools could allow quantitative estimation of benthic floral and faunal cover (identifying species from high resolution imagery) including benthic fishes, epi-benthic fishes (from forward looking or oblique video), and ground truthing of major habitat features. A USBL tracking system attached to the ROV allows precise, metre scale, co-location of acquired imagery for cross validation against high resolution base maps (acquired by multibeam sonar) from which to test and derive biophysical relationships.
The proposed PhD project would deploy the IMAS Seabotix LVB 300 ROV over a range of mapped cross-shelf habitats in eastern Tasmania to begin evaluation of deployment methods and the quality of data able to be obtained from the imagery. Following initial evaluation of the nature of data able to be obtained, the project will examine the statistical design issues associated with planning sampling strategies that can describe and monitor, with specified power,the biota associated with major habitat features, depth and latitudinal gradients. The PhD will also consider the statistical issues associated with the post-process sub-sampling and subsequent analysis of AUV data, specifically addressing issues such as autocorrelation between images and the implications of separation distance between transects for subsequent data analysis methods. One focus would be to evaluate these issues with respect to important biological indicators of change identified by the NERP Marine Biodiversity Hub. The PhD will be supported by the Marine Biodiversity Hub with supervisory input from several Hub partners, including UTas, CSIRO and Geoscience Australia.
Dr Eric C. J. Oliver (supervision contact)
Dr Mark Baird (CSIRO)
The surface waters of southeast Australia are warming at almost four times the global average rate (Holbrook & Bindoff, 1997; Ridgway, 2007), and this warming is associated with the multi-decadal intensification of the South Pacific gyre and southward extension of the nutrient-poor East Australian Current (EAC). This warming is projected to increase under anthropogenic-driven climate change (Matear et al, 2013) and may lead to dramatic changes to extreme ocean temperature events off southeast Australia, not only in terms of their increased frequency, but also their persistence – known as "marine heat waves" (Oliver et al., 2014). Much effort has focussed on understanding the offshore warming and forcing mechanisms (e.g., Cai et al., 2005; Cai, 2006; Sun et al., 2012; Oliver and Holbrook, 2014). However, comprehensive investigations of the coastal effects of this warming have been limited due to the paucity of coastal oceanographic observations and absence of high-resolution model data across the continental shelf. The large-scale warming of Australia's southeast region is nevertheless expected to have implications for biological productivity and, by extension, human interests in the region such as fisheries and species conservation. In particular, the impact of this warming on coastal marine heat waves, which are poorly understood in this region, are of great interest. It is important to understand how this dramatic change in Australia's southeast regional marine waters is related to, and affects, the shallow waters of the continental shelf.
High-resolution predictions of ocean variability on Australia's continental shelf are essential for characterising how the complex near-coastal marine climate (e.g., circulation, temperature, salinity) and ecology will change in the coming decades. Existing observations are too sparse in time and space to adequately characterise the ocean variability that define the relevant coastal oceanographic processes at the scales of ecological importance. Efforts to provide reanalysed ocean variability using data-assimilative numerical models have had success in predicting the large-scale ocean circulation but the model designs have limited the accuracy of predictions of ocean variability on the continental shelf (e.g., Bluelink ReANalysis, or BRAN). Some regions have employed high-resolution regional models to address this limitation through dynamical downscaling (e.g., using: SAROM in South Australia; SEAPOM in New South Wales; eReefs for the waters of the Great Barrier Reef) but there has not been a regional-scale downscaling effort for the continental shelf around Tasmania. We intend to develop and implement a high-resolution regional model for southeast Australia (focused at first on Tasmanian waters) to downscale BRAN and future marine climate projections onto the continental shelf. This will enable questions to be answered regarding changes in marine climate on the continental shelf at scales and locations that are in line and more consistent with the biological changes that have been observed, and are of concern into the future.
Skills Needed to Complete Project:
First Class Honours (or equivalent) or Master's degree in physical oceanography, physics or mathematics required. Desirable skills include familiarity with computer programming languages (C, FORTRAN, MATLAB), ocean dynamics, and time series analysis.
Noctiluca scintillans red tide frequency and distribution has increased in Tasmanian waters, Australia since the first sighting in 1994 and severely threatened Tasmanian aquaculture farms in 2002. We seek to identify key prey items for this phagotrophic dinoflagellate in Tasmanian waters from combined culture and field studies, as well as aim to elucidate the production of anoxia, ammonia or polyunsaturated fatty acids as the mechanism for fish morbidity and mortality.
The concept of offsets, though well developed and applied in terrestrial resource-based and energy sectors, has not been tested in marine-based aquaculture. This project examines the applicability of offsets as an instrument to achieve optimal social, economic and environmental returns from marine ecosystem services from marine-based aquaculture activity. Using a case study of Integrated Multi Tropic Aquaculture in Tasmania, this project will develop and test ecological, economic as well as social criteria for determining the equivalence and acceptability of impacts and benefits generated by proposed offsets. It will compare the outcomes of combinations of public policy settings and proposed offset strategies in order to inform both marine spatial planning and ecosystem-based management processes, and models of sustainable and socially-supported aquaculture production.
Dr So Kawaguchi (supervision contact)
Dr Kerrie Swadling
Researchers at the AAD have recently shown that early embryonic development of krill is inhibited by ocean acidification caused by increased CO2 levels (Kawaguchi et al. 2011, 2013). This project aims to assess the sensitivity of Antarctic krill to ocean acidification using laboratory-based experiments. This information will then be used to identify how factors such as CO2 level, temperature, and food affect growth and metabolic parameters of krill, and to refine existing krill growth models.
Dr. Andrew Trotter
In early 2016 many oyster farms in south-eastern Tasmania suffered high mortalities due to the Pacific Oyster Mortality Syndrome (POMS) OsHV-1 virus. To support this industry the CRC-P Future Oysters program was developed and this PhD study is part of that program, in the project "Advanced understanding of POMS to guide farm management decisions in Tasmania". It aims to support the commercial production of Pacific oysters in areas affected by POMS through the analysis of farm production and management records, and a contemporary study of farm production systems and laboratory experiments on oyster survival over a wide range of environment conditions.
The PhD study will be undertaken in collaboration with Southern Cross Marine Culture Pty. Ltd., a major oyster farming business operating in Tasmania and South Australia. They are providing access to their historic farm management data sets and current POMS sampling program. These data will be analysed for ways to maximise oyster production in a changing and challenging environment. Factors to be investigated include farming methods, oyster age/size, genetics, handling, food availability and water movements under different environmental conditions, especially changing climate.
A series of on-farm trials and laboratory experiments will be conducted, aimed at understanding the importance of seasonal environmental changes and how environmental and farm management imposed stresses make Pacific oysters susceptible to OsHV-1. Familial heritage is known to play an important role in OsHV-1 susceptibility and may be incorporated into aspects of the study.
The results from the farm records analysis and laboratory and on-farm trials, in conjunction with results from other research in the CRC-P project, will be used to build models that can be extrapolated by other oyster farmers to develop their own POMS response strategies according to their own circumstances and farm conditions.
Associate Professor Rich Little (CSIRO)
Olivier Thébaud (Maritime Economics Unit, IFREMER, Brest)
Claire Macher (Maritime Economics Unit, IFREMER, Brest)
This project is a co-tutelle and is partially funded by IFREMER (France). The student should be trained in quantitative methods, including applied mathematics and/or simulation modeling and demonstrate a strong interest in integrated ecological-economic modeling. They should be able to work in both French and English speaking research environments and willing to engage in a co-tutelle PhD program. Skills in fisheries science would be appreciated. As this will be a co-tutelle arrangement, the student will occupy resources in Hobart for about half the studentship.
The student will be based at the CSIRO Battery Point Labs and the Institute for Marine and Antarctic science (UTAS) when in Hobart and RBE – Economie Maritime & UMR AMURE and UBO-IUEM, Plouzané in France.
The aim of the doctoral research will be to develop an ecological-economic modeling framework which can be used to evaluate alternative output-based harvest-control rules in mixed fisheries that are managed under Total Allowable Catches and allocation of individual catch shares, taking into account multiple management objectives. The framework will then be applied to a set of case studies in France and Australia, and used to compare the robustness of alternative control rules in the two different management contexts.
The approach will be developed in two stages. In stage 1, building on prior research carried out by the co-supervisors and collaborators on the Australian South-East Trawl Fishery, a general evaluation framework for harvest control rules in a mixed fishery with ITQ management will be developed using an analytical approach. This will be based on a stylized representation of the fishery, with global biomass modeling of biologically independent but jointly caught species for which Total Allowable Catches are set separately, and individual catch shares are traded on separate lease markets. Biological, economic and social limit reference points will be identified and used in a viability analysis of the alternative control rules, considering the setting of all TACs simultaneously.
The results from this first stage will emphasize the general principles which should drive the definition of harvest control rules in mixed fisheries under TAC management with individual catch shares that can be traded between operators, taking into account multiple objectives. It will lead to the preparation of a manuscript to be submitted to a high impact factor peer-reviewed journal.In stage 2, a numerical simulation approach will be developed and applied to selected case studies, following the general principles identified in stage 1. This will build on the IAM modeling platform which has been developed by Ifremer as an operational decision-support tool for the impact assessment of alternative fisheries management scenarios. The use of IAM will enable the inclusion of uncertainty via the incorporation of stochastic parameter values relating to both the biological and the economic characteristics of the case study fisheries. Alternative harvest control rules identified following the general principles from stage 1 will be tested for their robustness to uncertainty and for their capacity to achieve viable outcomes, given the case-specific viability thresholds that are identified for economic, ecological and social outcomes. Candidate case studies for this second stage include the Bay of Biscay demersal mixed fishery, the Gulf of Lyon demersal mixed fishery and the Australian South-East Trawl fishery.
It is anticipated that this second stage will lead to the preparation of at least two publications on (i) the presentation of the numerical simulation approach and demonstration of its application to a case study; and (ii) on a comparative analysis of the outcomes of applying this approach in different settings and with different management objectives.
Maugean skate (Zearaja maugeana) are only known from Macquarie and Bathurst Harbours (western Tasmania), and have been listed as endangered under the Threatened Species Protection Act (Tas), the EPBC Act (Comm), and the IUCN Red List.
The physio-chemical conditions in Macquarie Harbour have changed markedly since European settlement and the general decline in DO since 2009 , which occurred at the same time as the rapid expansion of marine farming operations, is likely to have had a significant impact on many resident species , including the endangered Maugean Skate. A recently funded FRDC project is examining the potential effect of low DO in Macquarie Harbour on the Maugean skate, however, there has been no investigation into the potential impact on that of its prey.
The recent completion of the first comprehensive study of the Maugean skate demonstrated that crustaceans were the most important dietary group, with crabs and shrimp the most important groups. As such, this project will sample known skate habitats for their prey species and examine the physiological tolerance of these species to low DO to determine the threat declining DO in the harbour poses to these species and ultimately, the skate itself.
The research aims to document relationships between feed formulation, dietary uptake, and nutrient retention in juvenile rock lobsters. The project will be integrated into the ARC ITRH on the Commercial Culture of Rock Lobsters and inform the development of rock lobster feeds. There will be a focus on developing models to predict protein and energy requirements and it will continue research previously done at IMAS by the current supervisors (Ward et al., 200; Amin et al., 2016). The research will focus on factorial modelling and experiments organised to provide components for the model. The influence of nutritional variables on protein and energy retention and on the model, these may include lipid and protein sources (Ward & Carter 2009). Factorial models are most often developed using nutrient intake and nutrient retention as the key parameters. This project provides an opportunity to examine in detail the respiration of lobsters feeding on different feeds using advanced intermittent flow-through respirometry techniques developed at IMAS for rock lobsters (Fitzgibbon et al., 2014). The final experiment will test improvements to feed formulations under pre-commercial conditions.
The aims of the research are to quantify relationships between nutrient intake and retention to develop factorial models to predict protein and energy requirements. The research will examine the influence of nutritional variables, such as lipid and protein source, and compare independent measurements of different model parameters (e.g. maintenance measured using respirometry v. change in biochemical composition). The research will improve our understanding of juvenile rock lobster nutrition and improve feed formulations.
Steven Phipps (click here to email Steven for more information)
Ben Galton Fenzi (AAD, ACE CRC)
The nature of the relationship between the Antarctic Ice Sheet (AIS) and the global ocean circulation remains uncertain. Proxy evidence suggests that cooling oceans lead to reduced melting of the AIS, increased formation of Antarctic Bottom Water (AABW) and a colder and saltier deep ocean; in contrast, warming oceans lead to increased melting of the AIS, reduced formation of AABW and a warmer and fresher deep ocean. These changes in ocean circulation have important implications for the global carbon cycle. Understanding of these processes is critical if we are to be able to predict future changes in the AIS, the global ocean and the nature of ocean-climate coupling.
This project will use the history of Antarctica and the Southern Ocean over the past glacial cycle to explore the feedbacks between the AIS and the global ocean circulation. State-of-the-art models will be used to simulate ice-ocean interactions, with a particular emphasis on ice shelf dynamics, and to test dynamical hypotheses. Proxy data from the Southern Ocean will be used to inform the experimental design and to validate the model simulations.
The researcher will use the Parallel Ice Sheet Model (PISM) to simulate the response of the Antarctic Ice Sheet to changes in ocean temperatures. During the first year, targeted regional experiments will be performed. The magnitude and distribution of the ocean temperature anomalies used to drive PISM will be guided by proxy data. Sensitivity experiments will also be performed to explore uncertainty arising from model parameterisations. During the second year, the CSIRO Mk3L climate system model will then be used to study the effects of the simulated Antarctic meltwater fluxes on the global ocean circulation. The proxy data will be used to validate these experiments. Finally, during the third year of the project, additional experiments using PISM and/or CSIRO Mk3L will be used to test dynamical hypotheses.
This project will suit candidates with a physical science/engineering background and well-developed numerical analysis skills. Experience in compiling and running scientific software will be highly advantageous for the purpose of completing the model experiments.
This PhD project is available through the Centre for Marine Socioecology, an IMAS partnership with CSIRO and the Australian Government.
Aysha Fleming, CSIRO
Beth Fulton, CSIRO
Jeff McGee, UTAS
Expected start date for this project is early in 2017, for further details please contact Dr Julia Jabour (email@example.com).
In May, 2013, the world passed the benchmark atmospheric concentration of CO2 – 400 ppm. This figure was once the line in the sand beyond which the world should not go, since it would represent 'dangerous climate change'. At the 21st Conference of Parties to the UN Framework Convention on Climate Change (UNFCCC), held in Paris in 2015, discussion centred on, inter alia, limiting temperature rise to 1.5º, or possibly 2º – a seemingly impossible task, despite the commitment of the countries present.
This commitment raises many uncertainties because of the generous considerations made to both developed and developing economies. Without being able (or willing) to entirely stop emissions, or to make them into so-called 'negative emissions', there will be (and this is evident already) increasing interest in geoengineering. This is the deliberate, large-scale intervention in the Earth's natural systems to counteract climate change, and there are a range of techniques under development or consideration. These include CO2 removal approaches such ocean fertilisation, afforestation, and direct CO2 injection, and solar radiation management approaches such as space reflectors.
In the Summary of the 2015 US National Academy of Sciences Report on Climate Intervention: CO2 Removal, it was noted that if society ultimately decides to intervene in Earth's climate, the Committee most strongly recommends any such actions be informed by a far more substantive body of scientific research—encompassing climate science and economic, political, ethical, and other dimensions—than is available at present.
It is this point that the project takes as its foundation – a holistic appraisal of international geoengineering research, combined with an assessment of the challenges (eg. transboundary effects, the global commons, international v. national legal approaches, and public acceptability), public perceptions, and legal and political approaches to best practice governance.
The stated objectives of the ARC Laureate project to which this proposal is attached, are:
This project will therefore involve a multi-faceted study of geoengineering and geoengineering governance, involving several phases of data collection, collation, analysis and dissemination, including
The project will adopt a mixed-methods approach to data collection, involving such techniques as desktop studies, interviews with scientists, scientific translation and communication, public data-gathering through such activities as surveys (eg. SurveyMonkey), and standard legal and policy textual analysis.
The project outcomes will include the convening of several users' forums at the completion of various milestones to inform the regulatory bodies and the Australian policy community of progress to date. Ideally the candidate will gain a place on Australian delegations to regulatory body meetings (eg. CoPs for the Convention on Biological Diversity or London Convention/Protocol) to gain first-hand experience of the international diplomatic and political context in which decisions are made.
The project outputs will include several articles to be published in international, peer-reviewed journals, during the appraisal phases. The key output will be a policy-makers' guide to good governance of geoengineering research.
Dr Mark Hemer (CSIRO)
The project aims to:
The project objectives are as follows:
The project pulls together two important datasets which have been produced by CSIRO in recent years. The student will become familiar with the third generation spectral wave model – WAVEWATCH III (the leading model for the global wind-wave modelling community) – carrying out simulations of the global wave field with and without surface ocean current forcing. These simulations will build on the existing CSIRO-CAWCR wind-wave hindcast dataset, which has been generated in recent years. A series of experiments will be performed by the candidate to explore the sensitivity of model simulations to forcing from global eddy-resolving ocean reanalyses (e.g., BLUElink Reanalysis (BRAN)) and nearshore hydrodynamic simulations (e.g., eReefs, Great Australian Bight models).
The performance of the wave model simulations will be measured relative to Australian and global wave observations collected from a range of platforms (remotely sensed altimeter and synthetic aperture radar, and in-situ buoys – all publically available).
The project requires strong quantitative skills through numerical modelling, sophisticated analysis of large complex observational and simulation datasets, and excellent data management skills. Consequently, it aligns well with the quantitative emphasis of the QMS program.
The first paper will likely encompass a sensitivity study of the global wave field to consideration of surface current forcing.
The project has ample scope to investigate these effects at (1) various spatial scales (e.g. Antarctic Circumpolar Current, East Australian Current, near-shore circulation), to resolve the importance of these processes at both the coastal (shoreline stability studies) and oceanic spatial scales (Stokes drift), and (2) various temporal scales, to investigate the influence at operational/syntoptic vs climatological timescales. This scope will allow the student to pursue, in further chapters, any number of aspects and applications of the field of study which are of personal interest to their education/ development.
Professor Matt King (supervision contact)
Dr Ben Galton-Fenzi
There is great uncertainty surrounding the degree to which the Antarctic Ice Sheet has contributed to sea level since the Last Glacial Maximum (LGM). The vast East Antarctic ice sheet is particularly poorly understood. This PhD project will use a high resolution ice stream/ice shelf model in order to better understand the retreat history of one of East Antarctica's major drainage basins, the Amery Ice Shelf/Lambert Glacier system. Model runs will be performed in order to best-fit geological and geodetic constraints, examining the response of the ice sheet to changes in ice-shelf basal melting, accumulation and relative sea level change. Extensions to this work include application to other major glacier/ice shelf systems and incorporation of the results in a model of Earth's response to ice-ocean loading changes, known as glacial isostatic adjustment. The project will use published ice history data and other publicly available data. Simulations will be performed using grants and allocated resources within the National Computing Infrastructure and the Tasmanian Partnership for Advanced computing.
Associate Professor Ashley Townsend
Current projections of future sea level rise suggest only modest increases in the mean global sea level by the end of the twenty-first century, but with large uncertainties. One source of uncertainty arises because current sea level projections do not include ice sheet-ocean dynamic feedbacks, whereby a warming ocean accelerates the rate of ice-sheet melting. Recent evidence suggests this mechanism may result in level rise of 40 cm by 2100 with a future commitment of up to 10 m if global air temperatures continue to increase to greater than 2o C above pre-industrial values. Ocean-forced instability of the Antarctic ice sheet has been observed in marine sediment cores and ice sheet modelling, and recent evidence suggests an inter-hemisphere atmospheric control on ice-ocean feedbacks. Furthermore, recent work indicates that the Antarctic ice sheet experienced much greater variability during the Holocene period than previously thought.
There is growing evidence for on-going changes in Southern Ocean and atmospheric circulation, which may have already contributed to accelerated melting of ice shelves buttressing Antarctic glaciers. Given the large potential impact on sea-level, there is an urgent need to understand the mechanism of ice-ocean feedbacks, and the stability of the Antarctic ice sheet. This project will address these needs using recently collected sediment cores from the continental slope adjacent to the Totten Glacier, East Antarctica. Multiple geochemical proxies will be used to reconstruct millennial-scale ocean and ice sheet dynamics to understand the East Antarctic’s ice sheet response to climate change.
Dr Alan Henderson
Dr Tim Gale
A/Prof Greg Smith
Spiny lobsters are one of the world’s most valuable seafood commodities making them an attractive candidate for aquaculture. They have many favourable biological features, however to date commercial scale aquaculture has not been possible due to major bottlenecks during the larval phase of development. The student will join a team of researchers working in the ARC Research Hub for Commercial Development of Rock Lobster Culture Systems, a world class facility in Tasmania. Project supervision will be provided by leading experts from the Institute for Marine and Antarctic Studies and the UTAS School of Engineering & ICT.
The PhD project will assess the biological traits of lobster larvae (phyllosoma) and exploit these to develop insitu counting and tracking methods for studying animal behaviour for deployment in mass rearing vessels. The development of such methods is challenging due to the small size and transparency of phyllosoma, and the range of possible movements and orientations the animals may undergo while inside the vessel. Spiny lobster phyllosoma range from 1.5 to 35 mm in total length, are almost entirely clear and have a maximum mass of 100 µg. The ability to have an accurate count of phyllosoma during culture is important for a number of reasons including, feed allocation and distribution, health monitoring and tank management decisions. Some commercial systems are able to perform larval counting inside small chambers or when larvae are in transit between culture vessels. However, due to the delicate nature of phyllosoma it is advantageous to use a passive system capable of operating inside the mass culture environment. The project will develop motion tracking systems which are a crucial requirement for performing quantitative measurements of larval distribution and also provide ongoing monitoring of stock levels.
Assoc. Prof Peter Strutton (supervision contact)
Dr Klaus Meiners
Retreating sea ice in spring and summer can trigger extensive phytoplankton development, by inducing stratification of the ocean's surface layer and release of sea ice algae and ice-bound micro-nutrients into the water column. Off East Antarctica, ice edge blooms are temporally and spatially dynamic and the physical and biological key drivers in their occurrence and development remain unclear. The objective of this project is to assess the relative importance of various processes in triggering ice edge phytoplankton blooms. Data will be taken from remotely-sensed sources (e.g. ocean colour and sea ice concentration), model outputs, and in-situ observations. Numerical and statistical methods will be used to examine the influences of various processes, and to use those models to characterize and predict regional patterns in ice-edge phytoplankton blooms.
The response of climate variability to climate change forcing is one of the most important issues in climate research. Australia's highly variable climate is influenced by climate drivers such as El Nino - Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), the Southern Annular Mode (SAM) and the mid-latitude long-wave pattern and related atmospheric blocking. Climate-change induced modifications to the characteristics of these modes may result in significant changes to the variability and extremes in Australia's temperature, rainfall and evaporation. These changes may require substantial adaptation by climate-sensitive sectors such as agriculture, water resources and the urban environment.
Coupled ocean-atmosphere climate models are being used to make predictions of climate change and climate variability. These models explicitly represent climate processes on all timescales, from long-term climate change, through interannual climate variability down to daily weather systems. It is important that we understand how accurately climate models represent these processes in the past in order to gain confidence in their predictions. Where dynamical processes are not modeled well in comparison to observations, there is an opportunity to diagnose the causes and improve the models.
To inform planning and management decisions in climate-sensitive industries, it is imperative that climate models give accurate predictions, and that the level of accuracy is known for climate variables that are of most importance for the sector. For example, in rain-fed agriculture the rainfall distribution during the growing season is just as important as the rainfall total.
The main climate model used in this study will be ACCESS, the Australian Community Climate and Earth-System Simulator. The ability of this model to simulate the key drivers of Australian climate variability will be assessed. Are the model representations of ENSO, IOD, SAM and atmospheric blocking sufficiently accurate? If so, how do these climate modes change as the climate changes? What model deficiencies are revealed by these studies? Is it possible to improve the representation of key climate features in ACCESS?
For many industries in Australia the important climate variables are rainfall, temperature and evaporation, and their variability on daily, monthly, seasonal and annual timescales. The ability of ACCESS to make predictions about these key variables will be assessed. For example, does the model represent accurately the daily distribution of rainfall, and the way in which this varies from year-to-year? How does rainfall variability change due to climate change, and what are the implications for agriculture, water resources and other sectors dependent on climate?
Dr Richard Wilson
Dr Waldo Ortin-Nuez
This is an exciting opportunity to link in with international research on salmonids, Atlantic salmon, rainbow trout and chi nook salmon, and to gain skills and experience in forward looking technology around molecular biology and recirculation aquaculture systems. The research will focus on understanding the impact of nutrition and environmental change under controlled conditions on large Atlantic salmon. Environmental variables include temperature, salinity and pH because these impact on industry performance and sustainability. Nutritional variables include feed formulation and ration. Feed formulation will be done in consultation with industry partners.
Your research will advance fundamental knowledge about the Atlantic salmon proteome and how proteomics can be used to understand drivers of growth and growth efficiency. The project will develop proteomic based methods and relate this to gene expression based approaches. The research will contribute to sustainable aquaculture by understanding what happens to salmon when exposed to various situations that may be encountered in aquaculture. It will equip you with a range of new skills from maintenance of fish to advance molecular analyses.
Adam Treverrow (ACE CRC, UTAS)
Jason Roberts (AAD, ACE CRC)
Roland Warner (ACE CRC), AWI Collaborators (Alfred Wegener Institute, Germany)
The numerical relation describing the flow properties of ice is a fundamental component of models used to predict the dynamic evolution of the Antarctic Ice Sheet. In this project a comprehensive program of laboratory ice deformation experiments, combined with microstructural analyses will be used to improve the numerical relationship governing ice flow rates in ice sheet models. In particular, the effects of complex flow configurations and temperatures close to the melting point will be investigated experimentally with results used to develop an improved flow relation which will be evaluated using a regional-scale ice sheet model.
Dr Sean Riley
Prof Bill Maher (University of Canberra)
Metal contamination is a feature of many urbanised estuaries. Mercury (Hg) is of particular concern because it readily bioaccumulates up food chains, with potentially critical consequences for the health of ecosystems. It is primarily the methylated form of mercury (MeHg) that has implications for wildlife and human health. Most MeHg is produced in sediments, where the less toxic inorganic Hg is methylated by bacteria into a highly toxic species, MeHg (Ekstrom et al., 2003). This process can be influenced by a range of environmental factors that either directly affect the methylation process or the availability of Hg species for transformation. It is well documented that certain areas within estuaries can be mercury methylation "hotspots"; areas such as wetlands and seagrass beds. Anaerobic conditions tend to underpin the sediment biogeochemistry in these areas, which results in enhanced microbial sulfate reduction (an anaerobic process that is a key driver of mercury methylation). These areas also tend to be significant nursery habitats for estuarine and coastal fish species and as such, represent an important, but poorly understood, risk pathway for trophic bioaccumulation and a threat to fish stocks.
Mercury contamination is a key issue for the Derwent estuary, with current levels detected in sediments and biota being well above nationally recommended environmental and human health guidelines. While some heavy metals in the most heavily contaminated areas of the Derwent are declining in response to industry regulation/mitigation activities, Hg remains a significant concern due to its persistence and bioavailability. A public health warning issued in 2011 advised against eating fish from the catchment area based on research showing that mean Hg concentrations of key recreationally caught fish species exceeded the FSANZ guidelines (Verdouw et al., 2011). Recent research has shown that Hg levels in fish species within the estuary are inherently tied to the background environmental loadings, but that other biogeochemical processes can influence bioavailability and toxicity (Jones et al., 2013a,b).
This PhD project will explore Hg cycling in methylation "hot spots" in the Derwent estuary. The project will investigate methylation processes and biological transfer pathways with a view to identifying the environmental conditions that both promote and moderate mercury bioavailability (toxicity), in such areas. Changes to the sediment biogeochemistry either as a result of natural ecosystem dynamics or as a result of specific interventions (i.e. active remediation or management strategies) will influence the mercury methylation potential and as such, the mercury bioaccumulation risk for juvenile fish species that populate these habitats.
This project will inform understanding of the pathways for mercury bioaccumulation and link the chemistry and biology in these "hotspots" to identify those environmental conditions that present the greatest risk to juvenile fish. This information will be used to model the key interaction and risk pathways, which will in turn allow testing of potential management strategies for these habitats. This will ensure more effective management and remediation actions. Worldwide, many estuaries face a similar fate to the Derwent, and the lessons learnt here will be useful additions to the knowledge base as authorities elsewhere try to find the best way to monitor, manage and minimise the impacts of Hg contamination.
A key component will be the development of a qualitative (and potentially semi-quantitative) model identifying the relationships between sediment biogeochemistry, biology, and environmental conditions in these "hotspots". This research will underpin management strategies for these areas specifically, and will provide much needed information to support management of Hg contamination in temperate estuaries more broadly. The Derwent Estuary Program strongly supports this project and is willing to provide resources to support the research. The study is well aligned with their strategic management objectives for the overall remediation of the estuary. The project outcomes will provide valuable scientific input for ongoing management and the implementation of effective mitigation strategies for Hg contamination in the Derwent estuary.
Jason Roberts (AAD/ACE CRC)
Leo Peters (IMAS)
The flow of ice is very strongly controlled by conditions at the base of the ice sheet, including the type of rock or sediment and the presence of liquid water. This has large implications for not only the flow of the ice sheet, but the mass balance of the ice sheet, and hence impacts on both sea-level change and circulation in the oceans. This project will explore the subglacial hydrological environment beneath the little studied East Antarctic Ice Sheet. The candidate will make use of new airborne geophysical data and numerical modelling to quantify the production, distribution, and flow of sub-glacial water in East Antarctica.
Dr Petra Heil (supervision contact)
Dr Jason Roberts
The Antarctic ice sheets are a critical component of the dynamic link that couples the spatially and temporally varying components of the Earth system. Recent ice-shelf break-up (e.g. the Larsen and Wilkins ice shelves) and glacier tongue disintegration has increased the exposure of the Antarctic ice sheet and may lead to changes in the mass and geometry of high Antarctic ice masses. This project will focus on quantifying the processes that affect moisture flux onto the East Antarctic ice sheet, and their subsequent effects on the East Antarctic surface mass balance and geometry. Data will include meteorological data from automatic weather stations and manned observatories (station, vessels), and remotely-sensed parameters. Numerical models will be used to characterize the effects of these parameters on the surface accumulation of the ice sheets.
Dr. Tessa Vance
Dr. Mark Curran
Dr Carly Tozer
The IPCC has identified volcanic eruptions as an important natural forcing on the pre-industrial climate system. Tropical eruptions release massive volumes of sulphur aerosols into the stratosphere which lead to temporary global cooling. Therefore, quantifying the impacts of volcanic forcing is important for historical climate simulations and climate sensitivity estimates. The current estimates of volcanic forcing from ice core records are limited by our understanding of the many sources of sulphate and the proportion of the sea salt component (which is often the largest). Therefore an important aspect of this study is to understand sea salt variability and controls on sea salt sulphate. Additionally there is ongoing debate regarding frost flowers as a source of sea salts to the Antarctic interior. Sea salt originating from frost flowers on sea ice are depleted in sulphate relative to that originating from seawater. Therefore an understanding of the frost flower component of sulphate aerosols is critical to our understanding of the sulphate signal and estimating the volcanic proportion. This study will use a newly drilled ice core from an inland site in the Aurora Subglacial Basin, East Antarctica (ABN) as a bridge between the trace chemical records of coastal and plateau ice core sites to further the understanding of the atmospheric transport pathways of volcanic and trace ions to Antarctica. The low snow accumulation rate at ABN should reveal additional smaller eruptions over than those with higher accumulation rates.
Jason Roberts (AAD, ACE CRC)
Duncan Young (U Texas at Austin, USA)
Adam Treverrow (ACE CRC, UTAS)
Changes in atmospheric acidity, for example from volcanic eruptions, are captured by falling snow which is subsequently buried by additional snow falls and is advected into the interior of the ice sheet. These changes in acidity cause changes in the dielectric properties of the ice, and can therefore be detected by ice penetrating radar, and the layers may extend for hundreds to thousands of kilometres and reflects the current location of what was the surface at some time in the past. This project will use the spatial distribution of such isochrones and depth dating from ice cores to study palaeo-accumulation, basal melt and ice dynamics.
Dr Ming Feng (CSIRO)
Although the concentration of atmospheric greenhouse gases has been increasing at an accelerating rate for the past decades, the average rate of global surface air temperature rise has remained constant since the start of the 21st century. This apparent inconsistency was termed the global warming hiatus and was highlighted in the IPCC Fifth Assessment Report. England et al. (2014) suggested that a persistent la Nina state, in conjunction with intensified trade winds, caused enhanced heat uptake in the Pacific Ocean, accounting for the “missing” heat in the atmospheric climate system. Despite having absorbed additional heat, the heat content of the upper Pacific Ocean has not increased over the past decades. Rather, the absorbed heat has been transported into the Indian Ocean via the Indonesian Throughflow. This export stimulated the redistribution of heat to depths (> 50), making it unavailable for the atmospheric climate system and therefore contributing to the slower rise in surface air temperatures. The local changes in distribution of heat and salt associated with this heat export remains unknown. In particular, the impact of these watermasses modifications on Indian Ocean currents is yet to be studied. There has been increasing trend of marine heatwaves (MHWs) in the southeast Indian Ocean during this climate change hiatus period.
As a result of global ocean warming, MHW have been increasingly observed around the world oceans (Hobday et al. 2016). MHWs have dramatic impacts on local climate and biological systems. For example, a MHW event along Western Australia in 2011 resulted in +5oC sea surface temperature anomalies in the Leeuwin current, causing widespread coral bleaching and increased fish mortality. Such extreme events are driven by intense strengthening of the poleward Leeuwin current, which transports warmer water farther south. This atypical eastern boundary current is maintained by a strong meridional pressure gradient partly forced by intrusions of fresher and warmer waters through the ITF. There are likely to be significant changes in the Indian Ocean under climate change, such as an increase of salinity gradients in the eastern Indian Ocean due to global warming would increase the meridional pressure gradient and strengthening currents near the eastern boundary. It is uncertain how these large scale changes would impact on the MHW frequency and intensity.
This project will investigate the following key questions for Australia and the Eastern Indian Ocean region:
1) Based on Hobday et al. (2016) characterisations of MHW, what is the impact of the decadal climate variations such as the climate change hiatus on the frequency and intensity of MHWs?
2) How does the Leeuwin current respond to a warming Indian Ocean?
3) How will the likelihood of MHWs in the southeast Indian Ocean change under climate change?
Spiny lobsters are one of the world’s most valuable seafood commodities making them an attractive candidate for aquaculture. Lobsters have many favourable biological features which makes them suitable for aquaculture however the bottleneck for closed cycle aquaculture has been difficulties in larval and early juvenile culture. Spiny lobster aquaculture research has been continuing at the Institute for Marine and Antarctic Studies (IMAS) since the 1990’s. Significant breakthroughs have been made so now IMAS is the only Australian institution to have closed the life cycle for three species of lobster. More recently, IMAS was awarded an Industrial Transformation Research (ITR) Program grant for the development of an Australian Research Council (ARC) Research Hub for Commercial Development of Rock Lobster Culture Systems. The ARC research Hub places IMAS at the cutting edge of lobster aquaculture research. The program will develop unique aquaculture systems to mass produce lobster seed stock. Developing reliable mass culture methods for holding early juvenile stages, including efficient feeding, is a key area of research for the program.
The development of economical and effective formulated feeds and feeding strategies is an important step in the development of new aquaculture species. Despite considerable research effort, poor performance on formulated feeds remains a major obstacle to commercial lobster aquaculture. Much of the previous nutrition research on lobsters has focussed on assessing performance of formulated feeds and dietary requirements of lobsters based on the feed nutrient composition. However, this assessment assumes that that the feed nutrients are bio-available to the lobster and there is growing evidence that many nutrient presented in formulated diets may not be effectively ingested or digested by spiny lobsters (Perera and Simon, 2015). This PhD project will focus on dietary factors which influence the feeding behaviour of lobsters and their effect on feed stability and nutrient leaching with the aim of gaining a more holistic understanding of nutrient intake. The project will utilize a range of techniques including video observations and more traditional measures of feed intake to examine the effects of formulated feed form, presentation and life stage. It will concentrate on the early juvenile nursery phase which remains a significant bottleneck for commercial production and a poorly understood life stage. The project provides a unique opportunity to examine cultured juvenile lobsters of known nutritional and genetic background.
Spiny lobsters are cryptic animals which are easily disturbed by human presence making it difficult to gain an understanding of their feeding response and behaviour though casual observations. The feeding behaviour of lobster is also more complex than many other aquaculture species because feeding is often delayed and crustaceans macerate feeds instead of swallowing pellets whole (Simon, 2009). These behavioural and mechanical aspects can complicate typical assessments of nutrient ingestion (such as apparent feed intake) and the evaluation of feeding efficiencies (such as feed conversion ratios). Gaining an understanding of lobster feeding response and behaviours can therefore provide important insights for assessing appropriate feed formulations and the influence of feeding schedules on dietary nutrient intake.
Feeding behaviours can greatly impact the degree of feed or nutrient losses arising from poor feed stability and wastage. Leaching is dependent on a range of factors including the dry matter water stability of the feed, levels of water soluble nutrients, and the time spent in the culture water before consumption. The timing of the feeding response is thus an important consideration in the assessment of crustacean formulated feeds and can be influenced by numerous factors including attractiveness, form, feeding regularity and appetite revival of the lobster life stages. At present we have little understanding about the timing of feeding responses and the duration that feeds remain attractive and nutritious to juvenile lobsters. Lobster are also known to be “messy feeders” due to external handling and maceration of pellet diets (Sheppard et al., 2002). This feeding manner often leads to the total disintegration of dry formulated pellets and up to 50% food wastage. Previously video observation studies have shown that the amount of feed wastage can be dependent on the feed form and lobster size (Sheppard et al., 2002; Smith et al., 2008). These studies demonstrate the values of observational work for assessing the appropriate feed form in the development of artificial diets for spiny lobsters at differing life stages. By understanding the feeding response of juvenile lobster on differing formulated feeds and under differing feeding schedules, it may be possible to optimise various aspects of the feed formulation and feed management strategies to limit nutrient loss resulting from leaching and wastage.
Observational studies can also provide important insight into dietary preferences particularly for life stages. Mouthpart morphology of juvenile lobsters has been shown to change through early development which corresponds with ontogenetic changes in formulated feed preference and performance (Cox et al., 2008). Differences in feeding behaviour and morphology between lobster species suggest that formulated feeds need to be tailored for the specific species as well as juvenile life stage (Cox et al., 2008). Little is known about the ontogeny of feeding morphology of the lobster species cultured at IMAS including the tropical rock lobster (Panulirus ornatus), the eastern rock lobster (Sagmariasus verreauxi) and the southern rock lobster (Jasus edwardsii). Access to hatchery cultured lobsters of all species provides a valuable opportunity to conduct interspecific comparisons of feeding ontogeny of early juvenile lobsters.
Professor Andrew McMinn (supervision contact)
Recent technological advances in PAM (pulsed amplified modulated) fluorometry now allow us to characterize photosynthetic parameters of single algal cells viewed under a light microscope. This project seeks to apply this new toll to monitoring seasonal phytoplankton succession in the Derwent River with the aim to predict blooms of individual species and identify critical environmental variables.
Dr Edward Butler (CSIRO) (supervision contact)
Dr Jill Cainey (CGBAPS)
Dr Ole Hertel (NERI, Denmark)
Iodine is decisively a marinogenic element; its delivery to the land (and to terrestrial life) depends on the efficiency of its transport from the sea to the land surface via the atmosphere. The deficiency of iodine in many regions of the global land-mass remains a pivotal issue for human health, as
it does for agriculture—especially that of raising livestock.
The sea-air transfer of iodine is enhanced proportionately over the other halogens chlorine and bromine by volatile forms of iodine (organic and inorganic) formed in surface seawaters by biological and photochemical processes. These iodine volatiles in the atmosphere are extremely reactive. They are not only capable of catalytic decomposition of ozone, but they also form very fine aerosols that can influence global climate.
Delivery of iodine to land surfaces is either by wet or dry deposition, but a third pathway also exists with the uptake of gaseous iodine (e.g. methyl iodide) by plants and soils. The extent of retention of iodine is determined by the nature of the soils and the physiology of the plants. Regardless
of the importance of either soils or plants in intercepting iodine, neither can be considered as lasting repositories for the halogen. Iodine's reactivity ensures that it is either volatilised back to the atmosphere, or solubilised in surface run-off to enter again into the hydrologic cycle.
For the reasons touched on above—iodine's role in key atmospheric processes (cloud-condensation nuclei, albedo, and ozone destruction) and the efficiency of its transfer to land surfaces that ultimately underpins the nutrition of all higher terrestrial animals—it is critically important to be able to predict and understand the pathways, cycling and ultimate distribution of iodine throughout Earth's ecosphere.
The broad goal of this project is to develop a predictive, numerical model to describe the sea-air flux of iodine, its reactions and cycling in the atmosphere, and deposition to/emission from land surfaces. It is expected that the model will be calibrated and validated against relevant Tasmanian environmental data on iodine.
The PhD study can either involve: The development of a broadly based model to cover the full path (sea to air to land), or focus on development of a more detailed module (or nested model) for the full model—e.g. evasion of iodine from the sea, and its entry and cycling in the 'reactive iodine pool' in the atmosphere.
An associated task will include participation in the collection of atmospheric iodine data, relevant to the model, at the Cape Grim Baseline Atmospheric Pollution Station in North-West Tasmania.
The focus for this study will be the island of Tasmania and its surrounding seas. The reason for this is that a useful data set has been, and continues to be, obtained for the distribution and the biogeochemistry of iodine in the regional sea through the collaboration of Institute of Antarctic and Southern Ocean Studies (University of Tasmania), CSIRO Marine and Atmospheric Research and the Antarctic Climate and Ecosystems Cooperative Research Centre. This is importantly complemented by the measurements of atmospheric iodine compounds by the Cape Grim Baseline Air Pollution Station (joint Bureau of Meteorology/CSIRO Facility) on the north-western tip of Tasmania. Furthermore, records exist in Tasmania relating to iodine deficiency in the island's landscape (e.g. state-wide distribution of goitre among livestock). This complete database on iodine provides the basis for calibrating and validating the model.
The development of the model is vitally dependent upon the modelling expertise (and model code) of the Danish National Environmental Research Institute—a principal partner in this project. For example, their DEHM-REGINA long-range transport model is seen as a likely key tool in the project. Local expertise, such as that involved with oceanic transport and biogeochemical models, and the resources of the CSIRO Atlas of Regional Seas, will also be required to construct the iodine model. It is also conceivable that satellite data (e.g. estimated chlorophyll) will contribute to this work.
Given the key role of the National Environmental Research Institute at Roskilde in Denmark, the PhD student is expected to make a number of short-term visits to this facility during their candidature.
Dr Nicole Hill (supervision contact)
The Southern Ocean and Antarctica are vast and remote and collecting in situ physical and biological data is challenging. Information from satellites, oceanographic floats, and other remotely sensed data provide synoptic information about the physical environment of the Southern Ocean that can be integrated into numerical or statistical models and validated with in situ data. This is an effective approach to maximising the utility of sparse biological data. The aim of the project is to improve the variety, coverage and/or resolution of key physical variables currently available for the Southern Ocean and Antarctica, evaluate their usefulness for describing biological patterns and to use these variables, in conjunction with other variables, to enhance our understanding of the distribution of benthic and pelagic organisms. The broad objectives are to (a) utilise existing physical datasets and numerical or mechanistic models to extend the spatial coverage of and, in certain regions, downscale estimates of key ocean variables (for example carbon flux and pH) (b) contribute to the development of new physical variables to characterise the biologically-relevant properties of the Southern Ocean at a range of spatial scales and resolutions, and (c) evaluate and apply these surrogates for describing and predicting patterns in the distribution of zooplankton and benthic invertebrate organisms.
Dr. Damian Murphy
Waves generated by disturbances to airflow by fronts, storms or orography have a critical influence in large scale atmospheric circulations. However, our limited knowledge of wave generation processes adversely affects our ability to represent waves in climate models, which are a key research tool underpinning global climate research and atmosphere-ocean interactions.
The Antarctic cryosphere is an ideal natural laboratory for studies of wave generation because convective activity is weak; this simplifies the potential generation mechanisms. Davis station is a highly-instrumented site: a radar wind profiler is capable of measuring horizontal and vertical winds at high time and vertical resolution and meteorological balloons are released regularly.
This project will combine our unique observing capabilities with high-resolution modelling to characterise gravity-wave generation in the Davis region of Antarctica. The large-scale influences and fine-scale responses will be described and links between wave activity and meteorological conditions sought. These links will inform the design of gravity wave parameterizations in climate and weather models.
Professor Chris Carter (supervision contact)
Dr David Wright (PanLogica Pty Ltd)
Recirculation Aquaculture Systems (RAS) use recirculation technology to maintain water quality through physical, chemical and biological treatment in order to reduce water exchange and address issues such as biosecurity, production costs and nearness to market. RAS are increasingly important in aquaculture including Atlantic salmon farming ( ; Carter 2015). RAS can be used across the Atlantic salmon life-cycle: eggs and young animals are maintained in freshwater and then transferred to seawater. In Tasmania, the salmon farming industry uses and continues to develop more sophisticated freshwater hatcheries based, however the salmon are then on-grown in the sea. However, the University of Tasmania is building an experimental facility (EAF) that will employ RAS technology for research on large salmon in seawater. IMAS also runs several freshwater RAS.
RAS employ various types of software and models and the aim of this PhD is to understand the characteristics of input and output data required for optimisation software. The optimisation software is provided by PanLogica, a world leading supplier of optimisation software to the global aquaculture industry, and the student will work with PanLogica and IMAS on both freshwater and seawater RAS production optimisation.
This research aims to develop an understanding of how to optimise the use of freshwater recirculation systems according to the proprietary optimisation models developed by Panlogica. Research will first focus on collecting and assessing the importance of different model parameters that relate to inputs such as volume of water used, water quality measurements, characteristics of salmon used, fixed costs and running costs. These data will be used to improve the optimisation model, improved versions of the model will be tested and further improvements made (and to reduce the amount of data collected). The last experiment will be designed to test the optimisation model.
The proposed research will be organised in the following sequence and to complete four experiments (Chapters 2 to 5). The approach and direction of the research is likely to change in relation to information from the first two experiments and to take advantage of any opportunities to work with commercial operations.
Chapter One. Literature review of software and modelling used for RAS. (first publication)
Chapter Two. Data collection and analysis of usefulness for developing optimisation models for freshwater RAS.
Chapter Three. Improved modelling for freshwater RAS based on identification of critical data characteristics.
Chapter Four. Modelling a comparison of two or more different design features for a freshwater RAS.
Chapter Five. Testing software and manipulation of systems. Final benchmarking and independent comparison of predicted against datasets.
Chapter Six. General Discussion
Philippe Ziegler (AAD)
Rich Hillary (CSIRO)
The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is responsible for the sustainable management of Antarctic and Sub-Antarctic fisheries. Toothfish fisheries around South Georgia, on the Kerguelen Plateau and in the Ross Sea are assessed with integrated stock assessment models that use tag-recapture data as their main indices of abundance. In addition, many exploratory fisheries are in development within the CCAMLR Convention area for which integrated assessment models have not been developed yet due to insufficient data.
Assessing these exploratory fisheries is challenging due to their relatively low catch levels and paucity of data, as well as spatial issues such as fish movement and annual variability in access of fishing grounds due to sea ice. This project will use simulation modelling to optimise data collection and develop robust assessment strategies for these fisheries.
Dr Terry O'Kane
Dr Peter McIntosh
El Nino Southern Oscillation (ENSO) is a global, seasonal climate anomaly controlled by ocean-atmosphere interaction in the central and eastern equatorial Pacific Ocean . Climate anomalies in the monsoon systems of Australia , Asia and Africa are also modulated by ocean-atmosphere interaction in the tropical Indian Ocean , where the dominant pattern is the recently discovered Indian Ocean Dipole (IOD) or zonal mode. ENSO can influence IOD by an atmospheric tele-connection but IOD also is able to grow on its own. This study will assess the mechanisms that control IOD and its predictability.
Professor Zhong-Yang HE
Professor Qing-Jun SHAO
The research aims to understand the protein metabolism of Chinese perch or Mandarin fish (Siniperca chuatsi) through linking nutrient requirement experiments to amino acid flux and aspects of protein turnover. Mandarin fish is a valuable aquaculture species in China and annual production is approximately 300000 tonnes. The development of formulated pelleted feeds remains challenging and provides an opportunity to conduct nutrient requirement research on protein, energy and essential amino acids. This information will provide a basis for increasing the efficiency of protein use and improve commercial feeds. Protein turnover combines two energetically expensive systems, protein synthesis and protein degradation. The quantity and quality of dietary protein have major impacts on protein turnover and therefore the efficiency of using protein. The PhD will combine nutrient requirement experiments with measuring components of amino acid and protein metabolism.
Practical components of the research will be carried out at the Zhejiang Provincial Ocean and Fisheries Bureau and the student will conduct field work in Hangzhou, Zhejiang at the Zhejiang Technical Extension Centre. This is an excellent opportunity to contribute to the development of an important aquaculture species and experience aspects of Chinese aquaculture (which accounts for 2/3 of the world's aquaculture production).
Dr Ben Galton-Fenzi (supervision contact)
Dr Guy Wiliams
John Hunter (ACE CRC)
Dr Steve Rintoul (CSIRO)
The Antarctic ice sheet is formed by the accumulation of snow over millennial timescales. The accumulated ice flows, under gravity, to the ocean as glaciers where they may begin to float as ice shelves. Ice is added to an ice shelf by inflowing glaciers and net snowfall on the upper surface, while ice is lost by melting at the ice-shelf base and iceberg calving from the front. The ice flux from Antarctica into the ocean is thus strongly influenced by the mass loss processes occurring beneath the ice shelves and through iceberg calving. These processes are important for the formation of deep water (e.g. Antarctic Bottom Water or AABW), which occurs in the shelf seas around Antarctica and ventilates the abyssal oceans.
AABW has been observed over the past few decades to be freshening. One hypothesis for the freshening is the increased melting of ice shelves in response to global warming. However, we do not yet fully understand the processes that link coastal Antarctic ocean processes to ice-shelf melting and dense water formation. The research project will seek to answer the following questions:
Of particular relevance to the project is the role of coastal latent heat polynyas as a source of dense water in the region of the Mertz Glacier Tongue (MGT). Water that circulates onto the continental shelf is modified through sea ice formation processes and interaction with the base of the MGT. It is known that the resulting water mass has sufficient density to become Antarctic Bottom Water (AABW) as it flows into the deep abyssal ocean. Buoyant glacial melt water that is released during the melting process rises along the underside of the ice shelf and is transformed to Ice Shelf Water (ISW). The glacial melt water can become locally supercooled at a shallower depth, leading to the formation of frazil ice and basal accretion of marine ice.
The interaction of the atmosphere with the MGT/ocean system is currently being investigated at ACE CRC using a modified version of the Rutgers version of the Regional Ocean Modeling System (ROMS). Initial results suggest that the circulation on the shelf region is seasonally controlled by the production of dense water from polynyas. The dense water also acts to block warmer waters from the open ocean moving onto the shelf region, leading to lower melt rates of the MGT during winter. The project would seek to both quantify and understand one or more of the aspects of the interaction processes that occur between the Antarctic ice sheet and the oceans. Focussing on the region of the Mertz glacier tongue, projects could include:
Dr Simon Wotherspoon (supervision contact)
Dr Simon Wright
Photosynthetic pigments (chlorophylls and carotenoids) are widely used as biomarkers to determine the abundance and taxonomic composition of phytoplankton populations. However, interpretation of pigment data is difficult because of the great diversity of pigment patterns in algae, and because the pigment content of each taxon can be variable. The CHEMTAX software, developed by CSIRO and the AAD, is the prime analytical tool for pigment-based marine ecology worldwide. This project will study recent developments in this field, including Bayesian methods (van den Meersche et al. 2008, Whiten et al. 2011), develop new software for use by the world's oceanographic and limnological communities, and study methods to improve analysis where ecological gradients (e.g. latitude or time) cause changes in the pigment ratios or communities.
Associate Professor Ashley Townsend
Our oceans are losing oxygen, a phenomenon referred to as "ocean deoxygenation". Global oceanic oxygen content has declined by more than 2% since 1960 (Schmidko et al. 2017). Ocean deoxygenation could have a profound impact on ocean biology, and could even accelerate the pace of climate change, by increasing the oceanic production of the greenhouse gas N20. However, our ability to predict the future course of ocean deoxygenation and its impact is limited because of the complex interplay between ocean physics and biogeochemistry in determining oxygenation levels. Studying the response of ocean oxygenation to past climate change events can illuminate the important processes involved. However, the geologic record of ocean oxygenation is limited: there are very few records of ocean oxygen anywhere that cover the full glacial cycle, or resolve high-frequency variability. To fill this gap, this project will generate proxy records of bottom water oxygen and bio-productivity at three sites on the south-central Chile margin back to the last interglacial period, reconstructing the full glacial cycle and the response to millennial-scale climate events. This will allow us to address two main scientific questions:
Question 1: When did oxygen first decrease in the SE Pacific, within the sequence of events beginning at glacial inception?
Question 2: How did oxygenation of the SE Pacific respond to the millennial-scale climate eventsthat occurred during the last glacial period?
Sue Cook (ACE CRC)
One of the most intriguing glacier observations of the last decade or so has been that the velocity of many large glaciers varies substantially from its long-term mean due to tidal variation in the zone where the glaciers begin to flow – their grounding zone (Anandakrishnan et al. 2003; Gudmundsson et al. 2006, 2011; Winberry et al. 2011; Rosier et al. 2015). Such changes in motion have been observed using GPS on large West Antarctic glaciers, with the changes propagating tens of kilometres upstream. Combined with modelling, they provide unique insights into the interaction of the ice and its bed, the role of subglacial water, and the sensitivity of glaciers to modest changes in forcing (e.g., Rosier et al. 2015).
In parallel the floating extension of entire glacier systems, the ice shelves, have also been observed to experience tidal modulation of their flow (Doake et al. 2002; King et al. 2011; Makinson et al. 2011). These include the large Ross and Ronne ice shelves, fed by large ice streams tens of kilometres wide, alongside the smaller Larsen C Ice Shelf (King et al. 2011) fed by relatively small glaciers by Antarctic standards. The precise link between the modulation of flow of grounded and floating ice is yet to be fully established.
The Larsen C Ice Shelf system's response to tidal forcing is little studied to date, in particular the upstream glaciers, and this PhD will focus on modelling the response of the Larsen C system to tidal forcing in an attempt to understand the characteristics of the glaciers feeding the ice shelf and their sensitivity to changes in forcing in their grounding zone.
The candidate will construct a viscoelastic finite element model of the Larsen C system. Modelling will commence with the creation of an idealised model of a single glacier being forced in its grounding zone, followed by the extension to a larger floating ice shelf. The role of subglacial water will be considered. The model will then be extended to 3D with realistic 3D geometry, created using existing airborne geophysical data which provide ice elevation and bedrock geometry. Spatially continuous ice velocity data are also available for model tuning. GPS data from the floating and grounded ice sheet provide both the tidal forcing and the surface velocity response, the latter acting as model validation. The final model will yield new insights into the sensitivity of this relatively northern glacier system to changes in forcing in its grounding zone.
Provide the context of the project that demonstrates the reason for doing the work and its relevance to IMAS research priorities. The statement should clearly illustrate the relationship between this proposal, work done previously and other work in progress. Bear in mind that this will be used in the description of the project on the Web.
The Salmon industry in Tasmania seeks to double production by 2030, but achieving this will require both new farm production approaches and expansion into new areas. Maintaining high environmental performance (a priority for both the industry and its regulators) requires an understanding of how farming in new areas might affect the environment. To ensure that management remains best practice, and farms continue to be efficient and sustainable, a reliable understanding of the local and broader scale impacts and potential interactions with other resource users are required. A research project funded by the FRDC has just commenced that will undertake a mix of modelling, field based studies and targeted experiments, with a view to characterising the extent of farming impact and identifying indicators that can be used to monitor for near and far-field impacts. The identification of suitable assessment sites will largely be based on modelling outputs, with targeted experimental studies then located at sites to assess environmental conditions before and after farming. This study will be undertaken in all of the current salmon farming regions (Lower Huon/ Channel, Storm Bay, Macquarie Harbour).
Dispersion modelling will be used to link off-site assessments to local scale studies, specifically to identify exposure to nutrients and sediments from fish farms. Ultimately, the deposition and dispersion models will provide an important predictive tool for determining risk to the ecology of soft sediment and reef habitats in areas where salmon farming occurs.
Dispersion modelling is used to identify the "footprint" of the farms either in terms of actual sediment deposition or the extent of nutrient dispersion. This estimate relies on accurate evaluation of the initial nutrient content of the feed/ waste material source. The leaching and degradation rates in these models are currently based on values from studies undertaken over 10 years ago and, whilst potentially quite conservative, these values would benefit from validation based on a more accurate and recent assessment based on diets currently in use.
Dr Maxim Nikurashin (supervision contact)
Dr Steve Rintoul (CSIRO)
Dr Andy Hogg (ANU)
The meridional overturning circulation (MOC) is a planetary-scale oceanic ﬂow which is of direct importance to the climate system: it transports heat meridionally and regulates the exchange of CO2 with the atmosphere. The MOC is forced by wind and heat/freshwater fluxes at the surface and turbulent mixing in the ocean interior. The MOC is closely tied to the distribution of water masses in the ocean and consists of two overturning cells: the upper cell, corresponding to sinking of dense water mass in the North Atlantic, and the lower cell, corresponding to sinking of the densest water mass around Antarctica. Paleoclimate reconstructions suggest that the MOC was quite different in past climates: the boundary between the two overturning cells was substantially shallower and the strength of the MOC was likely weaker during the Last Glacial Maximum than in the present climate. Various studies suggest that variations in the MOC may have been responsible for the low CO2 in the atmosphere in glacial climates.
While being crucially important for the climate system, the dynamics of the MOC remain poorly understood. A number of conceptual theories have been developed and tested with idealized numerical simulations. However, the relevance of simple conceptual theories to the MOC simulated with higher complexity models or observed in nature still remains unclear. The overall goal of this project is to test and further improve our understanding of the dynamics that governs the MOC in the ocean. The project will focus on the sensitivity of the MOC to changes in forcing conditions across models with various complexities, ranging from simple theoretical models to realistic ocean and/or coupled general circulation models (GCMs). A few specific objectives of the project are:
Results of this project will improve our understanding of the response of the ocean's overturning circulation to changing climate and hence the role of the ocean in past and future climates.
First potential publication: "The impact of the non zonally-symmetric wind and buoyancy forcing on the overturning circulation of the ocean".
The student will need an undergraduate Mathematics and/or Physics Degree.
Squalus acanthias is a common, small, demersal shark that inhabits cool temperate waters throughout the world. They are long-lived, slow growing, have a low reproductive output and have been shown to be vulnerable to anthropogenic impacts.
A discrete population of S acanthias appears to be resident in Macquarie Harbour, a large estuarine system in western Tasmania that is also the location of large-scale salmonid aquaculture operations. The species has apparently thrived in Macquarie Harbour and, because of their opportunistic feeding behaviour, now feed predominantly on aquaculture-derived sources. These include fish pellet overfeed and fauna that is displaced from aquaculture cages when they are cleaned. However, there has been a marked decline in dissolved oxygen concentrations throughout much of Macquarie Harbour in recent years, the impact of this change on the native fauna, including S acanthias is largely unknown.
Given the unique characteristics of this S. acanthias population, this project will aim to investigate the ecological role of the speciesinMacquarie Harbour. In particular, it will investigate the physiological tolerances of S. acanthias with respect to the environmental conditions encountered in the Harbour and the role the species plays in removing aquaculture-derived sources of organic matter.
Ben Galton-Fenzi (AAD, ACE CRC)
Jason Roberts (AAD, ACE CRC)
Sea level rise originating from Antarctica is difficult to quantify. Mass loss occurs through iceberg calving and ice shelf basal melting. While calving can be observed from satellite, large-scale surveys of basal melting are logistically impossible. Yet, ice shelf basal melting is thought to be the most important driver of sea level rise, as relatively warm ocean waters can melt deep grounded ice and therefore accelerate the flow the Antarctic Ice Sheet into the ocean.
Numerical modelling is an optimum tool for investigating basal melting. Using a state-of-the-art numerical model, modified for ice shelf-ocean interaction, the successful applicant will investigate basal melting of several ice shelves, with a particular focus on East Antarctica. Atmospheric interaction will be explored through coupling of sea ice - atmosphere - ocean models, with a focus on quantifying drivers of basal melt.
The successful applicant for this project will ideally have numerical experience and/or a background in physics, mathematics or oceanography.
Adam Treverrow (ACE CRC, UTAS)
Sue Cook (ACE CRC, UTAS)
Roland Warner (ACE CRC)
Layers of marine accreted ice represent a significant proportion of many large Antarctic ice shelves and are thought to enhance their stability; however, little is known of the flow properties of these layers. This project will involve a combination of laboratory ice deformation experiments on ice samples from the Amery Ice Shelf and 3-dimensional modelling of ice shelf dynamics. Experimentally determined parameterisations of ice flow properties will be used in the development of a regional ice shelf model which will be used to assess the influence of marine ice layers on ice shelf dynamics and stability.
Any person expressing an interest in this project should email both Prof Boyd and Dr Swadling during December and January due to leave.
This position will be part of the interdisciplinary team investigating and ARC-funded project “Geoengineering the Southern Ocean? A Transdisciplinary assessment”. The role will focus on the holistic evaluation of what drives the efficiency of the ocean’s biological pump. This will include desktop studies, laboratory and field based research, along with mathematical modelling simulations.
The ocean’s biological pump is a key conduit for the transfer of biogenic carbon into the oceans interior and for the replenishment of nutrients via remineralisation in the deep ocean. In the geological past, changes in the efficiency of the pump have been invoked as a candidate mechanism to account for about 1/3 of the observed 80 ppmv reduction in atmospheric carbon dioxide concentrations. Consequently, geoengineering of the biological pumps has been proposed as a potential mitigation strategy to alleviate increasing anthropogenic CO2 emissions.
Mesozooplankton and particle-attached microbes play key roles in the biological pump via particle transformations (solubilisation, grazing), building blocks for heterogeneous particles (faecal pellet carbon and other elements), and hence have a strong influence on the magnitude and efficiency of carbon export. This post-graduate research fellowship will explore how different mesozooplankton taxa contribute to particle transformations which in turn help to set the magnitude of the downward export flux, and hence how they help to modify the efficiency of the pump.
We are looking for a candidate to focus on a project that centres on the following topics:
Ecophysiology research has often considered individual variation of physiological traits as noise or error between measurements with little biological relevance. Recently, however, it has become clear that variability in the physiology of individuals is an important factor influencing growth and therefore affecting adaptation and life –history diversity within species. Intraspecific variation in energy metabolism has become a key area of research because of its profound influence on energy budgets and consequently broad ecological relevance. There is growing evidence to suggest that the metabolic phenotype of an individual is strongly related to behavioural traits, feeding capacity, growth potential and capacity to respond to environmental conditions. Individual variation of metabolic phenotype is thus an important consideration for understanding intraspecific diversity of performance and for predicting future responses of species and populations to a changing environment.
Cephalopods can exhibit incredible capacity for performance diversity and life-history plasticity. In particular, growth trajectories of cephalopods can display extreme variation at both an individual and population level, an alibility which is thought to be instrumental for the group to tolerate and capitalize on seasonal and long-term environmental change. The links between metabolic phenotype and individual performance capacities of cephalopods has not been previously considered. The lack of information and their huge individual variation in performance makes this a significant knowledge gap in cephalopod biology.
The physiological response of animals to the environment plays a dominant role in determining environmental tolerance and has been the focus of extensive research in the context of the ecological impacts of environmental change. Temperature is key environmental factor effecting performance of marine ectotherms through its strong influence on metabolic rates and oxygen demands. Information of the levels of intraspecific diversity of metabolic phenotype and its influence of individual ability to respond the environmental and ecosystem change will be fundamental for understanding the response of cephalopod populations to a rapidly warming climate.
The project objectives are to;
1. Examine the level of levels of intraspecific diversity and repeatability of metabolic phenotype within and across families.
2. Examine the relationship between parentage and metabolic phenotype.
3. Determine the relationship between metabolic phenotype and individual feed intake and growth capacity of juveniles.
4. Quantify the influence of feed availability on the relationships between metabolic phenotype and growth of juveniles.
5. Examine the influence of elevated temperature on objectives 1 - 3.
6. Develop and model on the influence of metabolic phenotype on growth capacity of juveniles based on feed availability and temperature.
The project will use Octopus pallidus as the model species.
Dr Petra Heil (supervision contact)
Dr Rob Massom
Sea ice is a crucial component of the Earth system due to its roles in controlling energy and moisture transfer between the ocean and atmosphere, ice-albedo feedback connected to polar amplification, and in marine ecosystems and bio-geochemical activity. This project will seek to quantify and characterize sea ice motion and deformation in the Southern Ocean, with a view to determining the drivers of these processes and to estimate their susceptibility to change under predicted atmospheric and/or oceanic change. The methods used for this project will include time-series analysis of Lagragian data, image cross-correlation of satellite-based swath data, and optimal interpolation to determine the baseline of Antarctic ice kinematics. Statistical analysis, including linear models and multi-variable correlation analysis will be used to determine the effect of external forcing on the sea ice.
Jason Roberts (AAD, ACE CRC)
The dynamics for ice flow is strongly influenced by the internal temperature distribution within the icesheet, with warmer, and therefore more deformable, ice leading to increased ice velocities, discharge of ice into the ocean and ultimately changes in sea-level. Additionally, melting at the base of the icesheet produces liquid water which may lubricate the ice/bedrock interface and further enhance local ice velocities.
The distribution of geothermal heat flux is a primary control on the temperature distribution within the icesheet (and the presence of liquid water at the base of the icesheet) but is poorly known for much of East Antarctica due to the sparsity of rock outcrops and associated geological measurements. What measurements that do exist suggest the geothermal heat flux is spatially highly variable.
Information on the englacial temperature distribution can be estimated from the attenuation with depth of ice penetrating radar signals. This project will estimate the englacial temperature distribution within the East Antarctic ice sheet using existing of ice penetrating radar data, combined with seismic data and borehole temperature measurements from existing deep ice-coring sites. The estimated englacial temperature distributions will then be used in an inverse mode icesheet model to estimate the spatial distribution of geothermal heat flux and compared to independent estimates of geothermal heat flux from airborne geophysical surveys.
The successful applicant for this project will need strong numerical skills, with a background in physical sciences and large scale fluid dynamics modelling.
Prof Caleb Gardner (contact)
Australia has the world's third largest EEZ, whether this is measured by total area or by the size of the more productive continental shelf region. Total area of the EEZ is around 8.5 million square kilometres (or even 10.5 million square kilometres including Australia's Antarctic Territory, although this is recognised by only four other countries!).
Despite this large area, fisheries production is very low with Australia harvesting only slightly over 100 kg from each square km of continental shelf. This is the second lowest level of national production globally. Eritrea is the only country that produces less and they contend with severe problems like piracy, which don't affect production in Australia.
This low level of production in Australia is not only of social and economic interest but also has political implications. Debate around issues like overfishing, aquaculture subsidies, marine parks, resource allocation splits between commercial and recreational fishers, and seafood imports often reference Australia's low fisheries production. For example, a paper in the Australian Medical Journal in 2014 made the extraordinary claim that Australians should be discouraged from eating seafood, despite acknowledged benefits to public health, because our EEZ was unproductive and that current consumption could not be sustained. These type of arguments rely on the claim that Australia's EEZ is vastly less productive than other EEZs. That is, our low production is a consequence of our lack of glaciation and large river outflows and fisheries are simply limited by the unproductive Australian ecosystem.
The argument that Australia's low production of seafood production is limited purely by ecology doesn't hold up under scrutiny. Many countries without large river outflows and primary production far less than that of Australia sustain harvests more than 20 times greater per square km than Australia (for example Morocco, Turkey, Maldives, Yemen, Italy, Sudan). All countries adjacent to Australia have production many times higher, including even East Timor, which has double the production despite recent political turmoil and limited infrastructure. Solomon Islands has 10x Australia's rate of production despite political turmoil and severe infrastructure challenges. We share the productive Coral Sea ecosystem with Papua New Guinea. Australia takes no tuna catch from this region while PNG harvests 200,000 tonnes.
Australia's fisheries production is clearly limited by more than an unproductive ecosystem with factors at play such as: (i) trade and competitive advantage of production (high labour costs); (ii) the political power of the conservation movement; (iii) political power of the recreation fishing lobby; (iv) regulatory barriers.
This project will explore the causes of under-utilisation, trends in under-utilisation, and the opportunity cost for the Australian community including access to seafood and public health.
Professor Matt King (supervision contact)
Dr Ben Galton-Fenzi
This PhD project will use a numerical ocean model to examine the role of tidal currents in the retreat of the Antarctic ice sheet since the Last Glacial Maximum. Model runs will be performed in order quantify ice shelf basal melt rates for a series of LGM and post-LGM ice sheet configurations. Extensions to this work include application to a time-stepping coupled ice-ocean model to quantify the total effect of tidally-driven basal melt on post-LGM ice sheet retreat. The student will have access to appropriate computer models as part of a larger modelling effort within UTAS / ACE CRC. Simulations will be performed using grants and allocated resources within the National Computing Infrastructure and the Tasmanian Partnership for Advanced computing.
IMAS has conducted surveys of recreational fishing activities for more than two decades, covering a period of significant management changes, variability in the abundance of some key species and changing fisher preferences. These surveys represent a rich dataset that includes detailed information about individual fishing activities as well as profiling information about the fishers themselves which can be linked directly to the fishing behaviour.
Characterising the heterogeneity of the recreational fishing population and how this links to fisher choices (as revealed by fishing behaviour) has important implications in understanding how the sector responds to changing resource availability and management intervention. Furthermore, societal changes, including an aging population, increasing urbanisation and cultural diversity, are factors that are having an influence on the nature and scale of the recreational fishery in Tasmania and globally.
Jason Roberts (AAD/ACE CRC)
Tessa Vance (ACE CRC)
The response of the Antarctic Ice Sheet (AIS) is one of the key uncertainties in projections of future global sea level rise. Changes in the volume of the AIS are driven, in part, by changes in air temperature, ocean temperature and precipitation. An understanding of the drivers of the Antarctic climate is therefore critical if we are to be able to generate reliable projections of future changes in global sea level. Thanks to the availability of high-resolution palaeoclimate proxy data, the past 2,000 years provides us with a valuable opportunity to improve our understanding of climatic drivers.
This project will combine novel climate modelling approaches with proxy data from natural archives in order to reconstruct and understand changes in the climate of Antarctica over the past 2,000 years. A global climate model will be used to simulate the response to natural and anthropogenic forcings, include greenhouse gases, the sun and volcanoes. Simple proxy system models will be developed, alleviating potential problems with the interpretation of proxy records by allowing for a direct comparison between the climate model simulations and palaeoclimate proxy records. Through data assimilation and the application of techniques for detection and attribution, it will then be possible to reconstruct changes in the climate of Antarctica over the past 2,000 years and to identify the drivers that are responsible.
This project will use the CSIRO Mk3L climate system model to generate multiple ensembles of simulations. Each ensemble will simulate the response of the climate system to a single forcing (orbital, greenhouse gases, solar and volcanic) over the past 2,000 years. These simulations will be used in conjunction with an existing ensemble of simulations, in which all of these forcings were applied simultaneously.
The candidate will then develop simple forward models for key Antarctic proxy systems, including sea salt and stable isotopes. By driving these forward models using data from the climate model simulations, it will be possible to simulate the responses ("fingerprints") of Antarctic proxy systems to natural and anthropogenic forcings.
Through the application of techniques for offline data assimilation, this will enable the direct assimilation of Antarctic and Southern Ocean proxy records into a climate modelling framework. The assimilation will generate a reanalysis of the Antarctic climate spanning the past 2,000 years, including air temperature, ocean temperature and precipitation. Through the application of techniques for detection and attribution, the fingerprints generated using the forward models will also be used to quantify the roles of natural and anthropogenic forcings in driving the Antarctic climate.
In addition to the scientific outputs, this project will generate a number of significant and high-value products:
This project will suit candidates with a physical science/engineering background and well-developed numerical analysis skills. Experience in compiling and running scientific software will be highly advantageous for the purposes of completing the model experiments.
Ben Galton-Fenzi (AAD, ACE CRC)
Terry O'Kane (CSIRO)
Sea level rise originating from Antarctica is difficult to quantify. Ice-ocean interaction at the base of ice shelves, such as basal melting, is critically important for determining the Antarctic contribution to sea level rise. Numerical ocean models present an ideal tool for investigating this interaction. Model runs are typically forecast or hindcast solutions for modelling realistic ice shelves or idealised process-oriented studies.
An under-explored option is inverse models. Variational methods allow the assimilation of observations and exploration of model sensitivities. The Regional Ocean Modelling System is a commonly used numerical ocean model, has been modified for ice shelf interaction, includes an inverse model. Using a newly-developed extension to the inverse modelling framework, the successful applicant will apply inverse methods to ice shelf-ocean interaction; initially focussing on sensitivity of cross-shelf exchange of oceanic heat to uncertainties in the primary forcings.
The successful applicant will ideally have inverse modelling experience and/or a background in mathematics/physics.