Study

Honours Projects

ACE water sampler: sample processing, analysis and interpretation of Southern Ocean Time Series trace element data

Supervisory Team:

Primary supervisor: Dr Pier van der Merwe

Co-supervisor: Dr Elizabeth Shadwick (CSIRO), Professor Andrew Bowie

Brief project description:

The fundamental role of the micronutrient Fe in controlling phytoplankton growth in large parts of Earth’s oceans and a lack of information on seasonal transitions in remote regions motivated us to create an autonomous water sampler capable of collecting uncontaminated open-ocean sea water samples with monthly resolution over a full annual cycle.

Phytoplankton are the base of the food chain, and take up carbon dioxide through photosynthesis and assessing Fe availability is thus essential to understanding both ocean productivity and our climate. This need is particularly important in the Southern Ocean where Fe limitation is widespread, and access is difficult, especially in winter.

To address this need, we have developed an autonomous system capable of observing iron concentrations over a full seasonal cycle, at the sub-nanomolar concentrations that are important in the open ocean. The ACE (automated clean environmental) sampler has been developed initially for 1-year deployments on oceanographic moorings. Twelve samples per unit can be programmed to collect 65 ml of seawater through a non-contaminating, primarily Teflon sample path.

During this project, the student will work alongside the team who created the ACE sampler to process seawater samples for trace metal analysis. Seawater samples will be processed through a SeaFast Preconcentration system and then analysed using an Inductively Coupled Plasma, Mass Spectrometer (ICPMS).  The resultant data will then be checked for oceanographic consistency and interpreted within the framework of our current understanding of Fe cycling in the Southern Ocean.

Given the deployment location at the Southern Ocean Time Series Observatory, a wealth of supporting data is available to build a coherent picture of the oceanographic processes occurring at the site. Supporting data (macronutrients, chlorophyll fluorescence, temperature, salinity, dissolved oxygen, alkalinity, pCO2, phytoplankton community data and sediment trap particle flux) will be accessed through the Australian Ocean Data Network portal and combined into a report or publication.

Skills students will develop during this research project:

  • Stringent trace element sample handling and laboratory procedures
  • Analytical chemistry: Seafast Pico preconcentration and ICPMS analysis
  • Data mining using online portals
  • Data interpretation
  • Report writing and/or publication.

Alternative impact indicators – Sound, light, taste and smell, how can these be used in marine condition assessments

Supervisor team may include:

Dr Catriona Macleod

Dr Jeff Ross

Adam Davey

Do they squeal, glow or create a stink when stressed? Many marine organisms will exhibit changes in their ecophysiology when put under environmental pressure, and these responses could be used to measure/ monitor environmental conditions. This project proposes to examine the responses of key species, which are known to have a clear ecological response to contamination (e.g. brittle stars (bioluminescence), polychaete (pheromones/ smell) to determine whether their responses can be quantitative measured and attributed to specific environmental.

Aquaculture Nutrition

Supervisor team may include:

Dr Louise Adams

Professor Chris Carter

Projects relating to core nutrition and animal performance research themes: Fishmeal replacement, nutrient requirement, digestive physiology or feed assessment in Atlantic salmon, trout, abalone, barramundi or prawns. Links with IMTA Nutrition-Environment and modelling. Please discuss directly with supervisors.

Are artificial spawning substrates the key to enhancing populations of the endangered Spotted Handfish in the Derwent estuary?

Supervisor team may include:

Dr Neville Barrett
Tim Lynch (CSIRO)
Mark Green (CSIRO)

The spotted handfish is one of only a few Australian fish species listed as highly endangered under the EPBC act. The species is primarily only found in the Derwent Estuary, with a life history (site-attached adults producing guarded egg masses that hatch as miniature adults with no dispersal phase) that restricts their capacity to move in response to a changing environment. There are multiple threats to this species, including a physically degraded environment within the river and an increasing abundance of introduced pest species that may compete for resources and modify habitats. Previous studies have suggested that predation on stalked ascidians by the introduced seastar Asterais amurensis may be particularly problematic for the handfish as they preferentially use the ascidians as substrates for deposition of egg masses. Certainly the short egg mass stage (up to six weeks) may be the most critical stage in  their life history. As a management response to this, artificial spawning substrates have been developed and planted out at known handfish 'hotspots" throughout the Derwent estuary.  Brief surveys of these substrates suggest they are indeed utilised by the handfish, although the extent that they are utilised in preference to other natural substrates has yet to be determined, nor has the likely survival of eggs on such substrates during the incubation period. A potential Honours project would examine the success of artificial substrates at a range of sites throughout the estuary relative to natural substrates, and document the overall survival of egg masses over this period and the types of threats that they are exposed to, (e.g. predation by seastars, fish, crabs etc) and the methods that guarding adults may use to prevent egg loss. It would utilise a range of technologies such as underwater GPS (to relocate each spawning substrate with eggs) and time-lapse GOPRO cameras.  This project is supported by the Derwent Estuary Program (DPIPWE) with a $2000 grant towards operating expenses of a dive-based research program, and with supervisory support from the Spotted Handfish advisory team, including representatives from IMAS, CSIRO and the Derwent Estuary Program.

Suitable for February or July start date.

Contact Dr Neville Barrett (neville.barrett@utas.edu.au) for more details.

Assessing the 'Lost Atlantis' between Australia and Antarctica – subsidence and role in paleo-oceanographic re-organisations

Supervisory Team:

Primary supervisor: Jo Whittaker

Co-supervisor: Taryn Noble

Additional supervisors: Isabel Sauermilch (Utrecht University, The Netherlands)

Brief project description:

This project addresses the Cenozoic evolution of the Tasmanian Gateway, which formed during the tectonic separation of Australia and Antarctica. The opening of the Tasman Gateway has been implicated in the initiation of the Antarctic Circumpolar Current, and possibly played a role in glaciation of Antarctica 34 million years ago.

Recent high-resolution ocean model simulations by our team demonstrate that only small changes in the depth of the gateway, from 300m to 450m, cause a fundamental reorganization of the Southern Ocean circulation patterns and dramatic surface water cooling (by >4°C) along the entire Antarctic coast.

Although the broader plate tectonic motion between Australia and Antarctica is well constrained, uncertainties remain around the detailed plate tectonic evolution of the Tasman Gateway and its evolving paleodepth, particularly through this crucial 300-450m transition. Additionally, controversies exist around when ‘shallow water’ ocean current flows commenced through the gateway, their directions, strengths, possible linkage to glauconite formations and climatic consequences.

In this project, you will constrain the exact timing of Tasman Gateway subsidence and bottom current flow directions and strengths through the Tasman Gateway’s centre. You will perform authigenic Neodymium (Nd) and Strontium (Sr) isotopic composition analysis and Argon (Ar-Ar) dating, on Eocene and early Oligocene samples taken from ODP 1171, DSDP 280 and 281 sites at the South Tasman Rise.

The key objectives of this project are to:

  1. build a well-constrained subsidence curve for the Eocene and early Oligocene:
  2. constrain bottom water flow direction and strength

Assessing the impact of seismic surveys on invertebrate mechanosensory organs

Supervisory Team:

Primary supervisor: Ryan Day

Co-supervisor: Jayson Semmens

Brief project description:

Increasing human activity in the ocean has resulted in a corresponding increase in anthropogenic aquatic noise, which is gaining recognition for its potential to negatively affect marine organisms. Aquatic noise can be an unintentional by-product of human industry, such as vessel noise from shipping traffic, or produced with a purpose, such as seismic surveys that are used to investigate the geology below the seafloor. Among the various sources of aquatic noise, the impacts of signals from seismic air guns have received a relatively great deal of attention, primarily in regard to whales and fishes, due to the high intensity of the low-frequency signals and the repetitious nature of surveys, which systematically ensonify hundreds to thousands of square kilometres over the weeks to months surveys are conducted.

Compared to vertebrates, the effects of marine seismic surveys on marine invertebrates remain poorly understood, with only a limited number of field-based experiments performed to date. However, multiple incidences of mass stranding of giant squid (Architeuthis dux) reported following seismic surveys in the general region led to the finding that the statocyst, the mechanosensory organ responsible for detecting gravity, body positioning, and movement that is commonly found in aquatic invertebrates, including bivalves, cnidarians, echinoderms, cephalopods, and crustaceans, showed extensive damage. In a field study, with a single air gun, southern rock lobsters (Jasus edwardsii) exposed to air gun signals showed damage to their statocyst. Similarly, in laboratory-based experiments simulating aquatic noise, squid and octopus have shown severe responses to exposure, with progressive degeneration of the statocyst sensory epithelia.

Based on the damage postulated to have occurred through exposure to seismic signals in the wild and noise exposure in a laboratory, understanding the impact of aquatic noise, and seismic signals in particular, on the statocysts of marine invertebrates is an important aspect of characterizing the effects of exposure and the development of approaches to limit impact. This project will use electron microscopy to examine the statocysts of both Octopus pallidus and J. edwardsii following exposure to a full commercial seismic survey at varying distances.

Skills students will develop during this research project:

Organisation; review and synthesis of literature; scientific writing; data analysis; scientific/critical thinking; electron microscopy.

Assessing the impacts of husbandry techniques on the physiology and performance of Atlantic salmon (Salmo salar) broodstock

Supervision team:

Dr. Kelli Anderson

Dr. Gianluca Amoroso (Petuna Seafoods)

Professor Abigail Elizur (University of the Sunshine Coast)

Salmonids have been farmed for decades in Australia, and ~50 000 tonne is produced annually in Tasmania, yet the industry faces challenges to long term stability due to climate change. This can be observed in outdoor pond and tank systems where the water reaches in excess of 22 °C in summer. To date, the impacts of outdoor pond culture on the physiology and reproductive performance of female Atlantic salmon (Salmo salar) has never been studied systematically, and it is therefore difficult to gauge the costs/benefits of using different broodstock management strategies. Thus, the first broad aim of the proposed work is to 1) characterise the impacts of pond and tank culture techniques on broodstock physiology and development, egg quality, and offspring performance.

The spawning period for the Tasmanian stock of Atlantic salmon is typically compressed relative to their northern hemisphere counterparts, and the reduced window for stripping and fertilisation increases the difficulty of managing a large number of broodstock during the spawning season. This project will trial the use photothermal manipulation as means of fine tuning the onset of ovulation and spawning in female Atlantic salmon, with the ultimate goal being to 2) stagger the spawning period for subsets of fish without reducing reproductive performance.

By utilising a range of molecular techniques, we will also assess the physiological responses of female salmon to the conditions tested, and understand the molecular processes that underpin reproductive performance.

Auto-fluorescent signatures of phytoplankton for rapid classification and assessment of physiological status

Supervisory Team:

Primary supervisor: Assoc. Prof. Christopher Bolch

Co-supervisor: Dr Lennart Bach (IMAS Ecology and biodiversity, Salamanca)

Additional supervisors: Dr Terry Pinfold (CSL Flow Cytometry, Menzies Institute, Hobart)

Brief project description:

Full spectrum flow cytometry is a powerful approach to characterise particles, especially those that contain naturally fluorescent light-harvesting pigments such as phytoplankton. The most recently developed analytical instruments have vastly improved spectral range and resolution, and are now capable of distinguishing subtle changes in cell fluorescence intensity and across the full spectrum of photosynthetic pigments. Recent preliminary work by the sjpervisors and others show that these instruments can distinguish differences in related species, different life-cycle stages, and also changes in physiological status, such as response to changed light/temperature and the onset of nutrient limitation. The Menzies institute recently acquired a new full-spectrum – the Cytek Aurora, to complement the hi-resolution the MoFlo Astrios cell sorting flow cytometer. Used together, these instruments may provide capacity for in-situ comparison and analysis of the physiological state of phytoplankton. However, to develop this approach, it is necessary to understand natural variation of induced fluorescence signatures, and how these signatures change in response to common environmental factors and stresses experienced by cells.

This project aims to systematically examine how spectral signatures vary between different phytoplankton species at species genus and class level. The broader objective of the work is to build a library of fluorescent spectrum profiles that can be used for automated classification of phytoplankton cells and physiological status from natural samples.

Skills students will develop during this research project:

The student will learn the following skills during this project. Flow cytometry; Algal and microbial culture methods; DNA sequencing and bacterial phylogenetics; NGS-based microbial community profiling; community and NGS-data analysis

Can engaging with the community really inform science or is it just hand waving?

Supervisor team may include:

Dr Catriona Macleod

Dr Emily Ogier

This project will look at how we can better relate community concerns and values to specific environmental outcomes and monitoring data.

Can You Really Trust a Model? Help Us Find Out

Supervisor team may include:

Dr Scott Hadley

Dr Catriona Macleod

Dr Jeff Ross

Models are only as good as the data that is put into them. There is potential for a couple of student projects here to test some of the established assumptions/parameterisation in our existing aquaculture interaction models (e.g. digestibility co-efficient, sediment resuspension and/or for the more mathematically minded how some of the model calculations are derived).

Chronic toxicity of the diatom Rhizosolenia amaralis and its role in bitter mussel syndrome

Supervisory Team:

Primary supervisor: Assoc. Prof. Christopher Bolch

Co-supervisor: Dr Mark Adams

Additional supervisors: (Kim Lee Chang, CSIRO) Research advisor

Location of student: Launceston only

Brief project description:

In 1987 a diatom bloom caused by the diatom Rhizosolenia cf. chunii (now known as R. amaralis) occurred in Port Phillip Bay Victoria that was associated with a strong bitter taste and subsequent mortality (from 30-95%) in range of shellfish including, oysters, scallops and mussels. Mussels in in particular became so unpalatable, that they were unmarketable for several months following the bloom (Parry et al. 1989), suffered extensive inflammation, lesions and degeneration of the digestive gland, and high mortality up to 8 months after the bloom. Despite the event being well documented, the suspected causative diatom, Rhizosolenia amaralis has never been successfully cultured and the thus the cause of bitter mussel syndrome remains unconfirmed and the toxic compounds involved unknown. The bitterness and toxicity also coincided with the presence of unusual long chain (C30) highly branched isoprenoid (HBI) alkenes in affected mussels that have been suggested to be resonsible for the bitterness (Volkman et al. .1994) - hypothesis that remains untested.

In late 2020, Rhizosolenia amaralis was successfully isolated and cultured by IMAS (Christopher Bolch) from intake water of an aquaculture facility suffering extended periods of high stock mortality. Now more than 30 years after the first “bitter-mussel” event, there is opportunity for a motivated research student to establish and confirm the toxicity of R. amaralis, the compounds involved in bitter mussel syndrome, and investigate the role of this diatom in chronic shellfish mortality.

Using controlled shellfish feeding experiments with R. amaralis cultures, the project aims to:

  1. Confirm the identity and relationship of R. amaralis to other Rhizosolenia species.
  2. Determine whether R. amarlis is the source of shellfish bitterness and chronic mortality.
  3. Establish the concentrations of R. amaralis that lead to bitterness of shellfish.
  4. Assess the nature of chronic shellfish mortality and associated pathological changes.

The student will also work with CSIRO-based lipid biochemists to establish whether HBI alkenes are produced by R. amaralis and whether these compounds are involved in bitter mussel syndrome.

Skills students will develop during this research project:

The student will learn the following skills during this project. Algal culture techniques, DNA sequencing and phylogenetics; Experimental methods/design for shellfish feeding experiments; histopatholgical methods.

Classifying Southern Ocean clouds using machine learning

Supervision Team:

Primary supervisor: Associate Professor Peter Strutton (IMAS)

Co-supervisor: Dr. Marc Mallet (IMAS), Dr. John French (IMAS, AAD)

Additional supervisors: Dr. Andrew Klekociuk (IMAS, AAD)

Brief project description:

Observations of clouds, precipitation and radiation over the Southern Ocean are of significant value to the climate modelling community. Recent radiation and precipitation observations on board MS The World and the Aurora Australis are augmented by All Sky Camera images, which can be used to understand cloud occurrence, fractional sky cover and type. The student will be responsible for training, testing and validating machine-learned algorithms to classify different cloud types and other observational phenomena.

Skills students will develop during this research project:

Machine learning, image classification, R &/or python, git/github, scientific writing and publication

Comparison of gut morphology in fresh water and sea water grown chinook salmon

Supervisor team may include:

Barbara Nowak

The student will do morphometrics on histological sections from selected freshwater and seawater grown chinook samples, including mucous cell counts.  Main areas - histology, morphometry and image analysis and statistical analysis.

Suitable for February or July start.

Contact: email Barbara Nowak for more details

Conservation of Spotted handfish

Supervisor team may include:

Dr Tim Lynch (CSIRO) Tim.Lynch@csiro.au
Dr Neville Barrett (IMAS)

Spotted handfish (Brachionichthys hirsutus) are a critically endangered anglerfish known from only 10 sites across the Derwent estuary and D’Entrecasteaux Channel. Since 2014 monitoring of these sub-populations has been undertaken using geo-referenced underwater photography.

This provides both spatial data on densities for ‘hot-spot’ analysis and also tracking of individuals as adult fish have unique spot patterns. To assist in data analysis the pattern recognition software, I3S, was successful trailed in 2016. Data collection will continue through 2017 and we plan to pursue a variety of conservation and behavioural research questions.

First, a simple minimum population size estimate is required to advise government for the immediate commencement of a captive breeding program.

Second, with the developers of I3S, the pattern recognition software program needs to be optimised for spotted handfish.

Third, distributions and movements of fish both within and potentially between sites needs to be determined for management of threats. Forth, the size distribution of fish, especially for recaptures, will be used to investigate age and growth to determine the species life span. Finally, a more sophisticated capture-mark-recapture model that takes into account life-history characteristics, needs to be developed to better estimate the population size.

The project will involve extensive small boat and diving field work. Candidates will hence need to have or be able to achieve the required certification for scientific diving prior to commencing field-work. This includes a recreational diving ticket, at least 20 logged dives and the ability to pass a diving medical. Candidates will also be expected to work towards a coxswain certification. With the exception of the initial recreational dive ticket all training and other expenses will be paid for by the project.

Suitable for February or July start date.

Contact Neville Barrett (Neville.Barrett@utas.edu.au) for more details.

Daily-ageing of Gambusia holbrooki, a short-lived pest fish, using novel molecular tools.

Supervisor team may include: 

Dr Jawahar Patil

Knowledge of population age-structure is necessary for stock assessments, and to develop management plans for invasive species such as the Gambusia. Size is generally associated with age; however, there are variations in size at any particular age for most fish species making it difficult to estimate one from the other with precision. Conventionally, counting natural growth rings on the scales, otoliths, vertebrae, etc has been used to good effect particularly in long-lived fish where the annual rings can be easily distinguished and annual aging is more appropriate for most management purposes. In short-lived species where they mature in months a daily ageing tool is necessary. Taking advantage of recent development in molecular biology this project will aim to establish a more precise againg framework, that is cross-validated with daily rings that may be laid on hard parts such as the otolith, scale and fin rays.

Suitable for February or July start date.

Contact Dr Jawahar Patil (jawahar.patil@utas.edu.au) for more details.

Degradation behaviour of plastic consumer products in commercial compost

Supervision team may include:

Dr Jennifer Lavers

Dr Morgan Gilmour

The project investigates the behaviour of consumer items, such as “biodegradable” dog poo and zip lock bags under a range of environmentally-relevant conditions. The candidate(s) will conduct a series of experiments in collaboration with the Hobart City Council waste management facility that will test the biodegradability of products in a commercial composting system. Candidates will investigate the degradability of these same items under environmental conditions, such as seawater and freshwater, using raceway tanks at the IMAS Launceston or Taroona facilities.

Degradation behaviour of plastic consumer products in commercial compost

Supervisory Team:

Primary supervisor: Dr Jennifer Lavers

Co-supervisor: Dr Morgan Gilmour, IMAS adjunct

Project partners:

  • Sophia Newman, Hobart City Council, Waste Education Officer
  • Jeff Holmes, Hobart City Council, Cleansing & Waste Policy Coordinator

Brief project description:

The project investigates the behaviour of consumer items, such as “biodegradable” dog poo and zip lock bags under a range of environmentally-relevant conditions. The candidate(s) will conduct a series of experiments in collaboration with the Hobart City Council waste management facility that will test the biodegradability of products in a commercial composting system.

Candidates will investigate the degradability of these same items under environmental conditions, such as seawater and freshwater, using raceway tanks at the IMAS Launceston or Taroona facilities.

Demographics of recreational fishing participation – understanding the past and looking to the future

Supervisor team may include:

Dr Jeremy Lyle

Dr Sean Tracey

The 2000/01 National Recreational Fishing Survey provided the first comprehensive assessment of recreational fishing in Australia. At the time an estimated 3.4 million Australians fished at least one a year, representing almost 20% of the total population. Participation rates did, however, vary widely by age, gender and area of residence. More recent surveys highlight a trend of declining participation that can be linked in part to changing population demographics. This project will review results of surveys of recreational fishing participation in the context of population demographics and the implications for future participation in recreational fishing.

Developing biomarkers of salmon farming: tracing feeds in the environment

Supervisor team may include:

This project will produce new laboratory based data to support field studies tracing impacts from salmon farming in the wider marine environment. There are several possible projects within this topic, possibly including field sampling from farms and estuaries and or lab-based feeding studies in abalone.

Suitable for February or July start date.

Contact Louise Adams (Louise.Adams@utas.edu.au) or Catriona Macleod (Catriona.Macleod@utas.edu.au) for more details.

Digestive system development in the tropical rock lobster, Panulirus ornatus and the slipper lobster, Thenus australiensis from late-stage phyllosoma to juvenile

Supervision team:

Dr Andrew Trotter

Associate Professor Greg Smith

Spiny lobsters have very high economic value that are captured and cultured in more than 90 countries. Aquaculture of spiny lobster has always been impeded by the lack of seed stock and all current industries rely of wild caught seed. Larval culture is very difficult, primarily due to the protracted larval cycle. Larval culture of spiny lobsters has been undertaken for 20 years at IMAS and three spiny lobster species have been cultured through the full larval cycle; including Jasus edwardsii, the southern rock lobster, Panulirus ornatus, the tropical rock lobster and Sagmariasus verreauxi, the eastern rock lobster(all Palinuridae). More recently IMAS has used culture techniques developed for spiny lobsters to successfully culture the slipper lobster, Thenus australiensis (Scyllaridae). It is likely that both P. ornatus and T. australiensis will be cultured commercially in the near future using technologies developed at IMAS.

Although the culture techniques are very advanced, some aspects of the larval biology are not well understood. Two of the most challenging developmental stages in the lifecycle of lobsters include metamorphosis, where a dramatic reconstruction in morphology occurs from the feeding phyllosoma larval stage to the non-feeding puerulus stage, and then the emergence from puerulus to the juvenile. During this time the digestive system transitions from processing planktonic to benthic prey with an intermediate non-feeding stage. The digestive system in particular undergoes extensive gross morphological transformation during these life stages but has never been characterised in detail in either species. A more comprehensive understanding ontogenetic changes during these life stages will provide insights/baselines to make improvements to larval and juvenile rearing, particularly in regard to health and nutrition.

Diversity and structure of dinoflagellate microbiomes

Supervisory Team:

Primary supervisor: Assoc. Prof. Christopher Bolch

Co-supervisor: Assoc. Prof. Andrew Bridle (IMAS);

Additional supervisors: Dr Terry Pinfold (CSL Flow Cytometry, Menzies Institute, Hobart)

Brief project description:

In the ocean, marine phytoplankton interact with both intra-cellular and extracellular bacterial symbionts in the diffusive boundary layer (DBL) around the cell. These microbiomes are essential for their growth and have major effects on their physiology and toxicity. Current knowledge of phytoplankton microbiomes is derived almost entirely from lab-based studies where microbiomes are extensively modified by both nutrient-enrichment and a closed environment, and the difficulty of sampling cell-associated microbiomes at the single-cell scale. As a result, we know almost nothing about microbiomes associated with phytoplankton cells in natural marine systems. Preliminary studies show that natural microbiomes are dominated by completely different bacteria to lab cultures, but it is not yet clear whether they share similar functional traits to those from cultured microbiomes. This project aims to use flow-cytometry and fluorescence-activated cell-sorting (FACS) with Next-Gen sequencing (NGS) microbial profiling (16S rRNA gene) to characterize microbial communities associated with natural cells of marine coastal dinoflagellates. Specifically, the project will:

  1. Establish the phylogenetic composition and structure of microbiomes associated with natural bloom cells of dinoflagellates.
  2. Culture and identify representative microbiome bacteria from FACS dinoflagellate cells.

Skills students will develop during this research project:

The student will learn the following skills during this project. Flow cytometry; Algal and microbial culture methods; DNA sequencing and bacterial phylogenetics; NGS-based microbial community profiling; community and NGS-data analysis

Effect of ecological and physiological factors on heavy metal uptake mechanisms in key estuarine species

Supervisor team may include:


Understanding trophic transfer mechanisms in marine species/ communities is an important precursor to clarifying contamination pathways, improving our understanding of the ecosystem and developing effective management and remediation strategies. This project aims to identify the main ecological and physiological factors associated with heavy metal uptake in key invertebrate and vertebrate species. Are they what they eat? How does environmental loading and metal speciation influence uptake potential? This information is important if we are to understand metal accumulation & toxicity, or to identify species with the potential to act as indicators of remediation and is essential for evaluating environmental impacts & developing risk/ management responses.

The project will use a combination of field based and experimental studies (potentially including both traditional dietary analysis techniques and stable isotope analysis) to clarify the relevant responses for key species. There is flexibility within the project to change the project emphasis to suit specific student interests/ capabilities; for instance the project can be focussed on comparison of uptake rates and mechanisms between different functional types within a location, within a species/ type, between locations or even to look at specific uptake pathways.

This project can be tailored to suit students with an interest and ability in either ecological or physiological processes.

There are six key research areas that have been identified as priorities in 2016:
Project 1 - How is metal accumulation rate in Flathead from the Derwent Estuary affected by growth conditions?
Project 2 – Heavy metal uptake in recreationally fished species from the Derwent estuary: Focussing on mechanisms of bioaccumulation & bioavailability.
Project 3 – What can 20 years of oyster sampling tell us about bio-monitoring?
Project 4 – Assessing the relationship between infaunal body burden and mercury load in contamination hotspots.
Project 5 – What is the proportional representation of mercury species in sediments?
Project 6 – What factors can increase mercury accumulation risk in methylation hotspots?

From these projects you may gain skills in: experimental design (field and laboratory), field sampling, conducting laboratory based experiments, statistical analysis, stakeholder interactions and publication of results.

Suitable for February or July start date.

Contact Catriona Macleod (Catriona.Macleod@utas.edu.au) for more details.

Evaluating productivity proxies in Antarctic margin sediments

Supervisory Team:

Primary supervisor: Zanna Chase

Co-supervisor: Taryn Noble

Additional supervisors: Layla Creac’h

Brief project description:

Primary productivity on the Antarctic margin forms the base of the marine food chain, is an important part of the global carbon cycle, and is potentially highly sensitive to climate change.

The Antarctic margin experienced dramatic changes associated with the glacial cycles of the Pleistocene, including large changes in ice sheets, sea-ice, ocean temperature and ocean circulation. By studying how primary productivity varied in response to past climate change, paleoceanographers can develop a framework for predicting how productivity might change in response of anthropogenic climate change. However, because we cannot directly measure productivity in the past, we rely on “proxies” of productivity preserved in marine sediment cores. These paleoproductivity proxies include geochemical proxies such as opal, organic carbon, carbon isotopes, and barite, as well as microfossil-based proxies such as diatom abundance and species composition.

The various proxies target different aspects of productivity, and have different biases and uncertainties. A multi-proxy approach, where multiple proxies are combined, can increase confidence in the inferred productivity. However, there have been relatively few studies of productivity proxies in the Antarctic marine environment. This Honours project will compare a large suite of productivity proxies in a series of sediment ‘multicores’ recovered from the east Antarctic slope off Wilkes Land. These cores recover the most recently deposited sediments, allowing a detailed study of proxy behaviour and comparison with modern conditions.

Ultimately, we hope to produce a robust, multi-proxy productivity index that can be applied to paleoceanographic studies.

The project aims are to:

  1. Evaluate the effectiveness of chlorin concentration and loss on ignition as inexpensive alternatives to more costly geochemical techniques for reconstructing productivity
  2. Compare the behaviour of different productivity proxies, between cores and down cores
  3. Compare sediment-based productivity proxies in surface sediments with satellite-based productivity data and oceanographic setting
  4. Determine the feasibility of establishing a productivity index that combines information from multiple proxies (Hebbeln et al. 2002)

Skills students will develop during this research project:

The student will gain skills in laboratory analysis of sediment samples and will gain expertise in sediment geochemistry and Antarctic margin environments. The student will also become familiar with a large suite of geochemical proxy data, including the processing associated with such data. The project will use statistical methods to compare sediment proxies and to derive a multi-proxy index. Finally, the student will learn how to access, plot and interpret satellite-based productivity data.

Evaluating the Australian climate model ACCESS-CM2 against marine aerosol observations

Supervisor:

Sonya Fiddes (AAPP)

Project description:

Aerosol, tiny solid or liquid particles suspended in the atmosphere, are one of the most uncertain aspects of climate modelling, having an important influence on the simulation of clouds and radiation (IPCC AR5, WG1, Ch8, 2013). Marine aerosol, such as sea salt or biogenic aerosol, make up a large part of this uncertainty (Carslaw et al. 2013, Nature).

Over the last five years, numerous observations have been made of marine aerosol, providing an opportunity to evaluate models with recent and high-quality data. The new generation Australian Community Climate and Earth System Simulator - Coupled Model 2 (ACCESS-CM2) model has an online aerosol scheme which can simulate the formation and influence of aerosol (Bi et al. 2020, JSHESS).

This project will evaluate the ACCESS-CM2 aerosol output against the recent field observations in order to understand how well the model is able to simulate aerosol variability and where the model might be improved.

Examining the Environmental Pros and Cons of Integrated Multi-trophic Aquaculture (IMTA)

Supervisor team may include:


IMTA has several prospective benefits for salmon aquaculture; including the provision of alternative product(s) and the potential to offset the adverse effects of nutrient inputs. However, it is important to understand all of the interactions to ensure the benefits outweigh any possible negatives.


It has recently been suggested that current net cleaning activities in salmon culture may have the potential for adverse interactions in co-production with shellfish depending on the nature of the fouling communities and proximity of the farming operations.
Whether this might be a significant issue for IMTA/ polyculture operations needs to be investigated. There are two key project areas that have been identified: Project 1 - Impacts of net cleaning on co-culture species (performance & growth) and Project 2 – How close is too close? How far away must co-culture species be to beyond any influence of net-wash material.

Suitable for February or July start date.

Contact Louise Adams (Louise.Adams@utas.edu.au) or Catriona Macleod (Catriona.Macleod@utas.edu.au) for more details.

Exploring lost microcontinents in the Southern Ocean

Supervisory Team:

Primary supervisor: Jacqueline Halpin

Co-supervisor: Jo Whittaker

Additional supervisors: Nathan Daczko (Macquarie University)

Brief project description:

During the breakup of the supercontinent Gondwana some ~120-95 million years ago, a massive outpouring of magma formed the then contiguous Kerguelen Plateau-Broken Ridge system. Embedded in this oceanic plateau complex was continental crust of unknown age and composition that slowly sank beneath the water hidden from view.

About 45 million years ago seafloor spreading along the Southeast Indian Ridge separated the enormous composite plateau into the Kerguelen Plateau and Broken Ridge, which are almost entirely submarine features that today remain poorly explored.

A recent research cruise aboard the R/V Investigator (IN2020_V01) sampled continental rocks from the William’s Ridge (central Kerguelen Plateau) for the first time. In this project, you will analyse key continental rock samples to determine their composition, age, evolution and affinity. You will integrate these new datasets with other geological and geophysical data to test hypotheses relating to the tectonic evolution of Gondwana and the formation of microcontinents.

Applicants should have a geoscience background, and preferably have completed 300-level geology subjects (including petrography).

Skills students will develop during this research project:

Petrography, geochronology, geochemistry, plate reconstructions, GIS

Factors affecting the post-mortem analysis of mucosal surfaces

Supervisor team may include:

Mark Adams

The skin, gill and gastric mucosae of many aquatic and terrestrial organisms can be collected and treated using different techniques to facilitate subsequent post-mortem analysis.  This project seeks to explore pre and post-mortem procedures that may affect the interpretation of mucosal surfaces.

Suitable for February or July start date.

Contact Mark Adams (Mark.Adams@utas.edu.au) for more details.

Human impacts threaten native kelps: What can be done?

Supervisory Team:

Primary supervisor: Dr Beth Strain

Co-supervisors: Assoc Prof Catriona Macleod and  Dr Wouter Visch

Brief project description:

This study will investigate the interactions between kelp farming the associated biofouling community. This project comes with a $2,000 AUD scholarship.

Specifically, the thesis aims to:

  1. Quantify the flora and fauna on 2 species of cultured kelps and bare ropes at 6 sites: 2 sites adjacent to finfish leases, 2 sites adjacent to bivalve leases and 2 sites, 2 sites with cultured kelps only in summer and winter
  2. Assess the effects of different amounts of flora and fauna on the performance of 2 species of cultured kelp at 6 sites
  3. Compare the flora and fauna on cultured and natural kelps, at 3 sites.

The results of this thesis will provide quantitative measurements of the effects of different types of kelp farming, on the associated flora and fauna. Furthermore, the findings of this study may offer novel insights into the best timing for culturing kelps in the IMTA system.

The student will learn key skills in fieldwork (eg. snorkeling), taxonomy, and quantitative ecology. The project will involve both laboratory and field work and data analyses.

Skills students will develop during this research project:

The student will learn key skills in fieldwork (eg. snorkeling), taxonomy, and quantitative ecology. The project will involve both laboratory and field work and data analyses.


For more information, please contact Dr Beth Strain

I Spy!! – Using Time Lapse photography to Inform Environmental Management

Supervisor team may include:

Dr Catriona Macleod

Dr Jeff Ross

Adam Davey

This project would look at using existing sensor and telemetry infrastructure to deploy time-lapse cameras in Macquarie Harbour in order to assess the response of key species to nutrient enrichment.

Indirect impacts of the range–extending sea urchin, Centrostephanus rogersii: a socioeconomic assessment

Supervisor team may include:

Dr John Keane

Dr Emily Ogier

Professor Caleb Gardner

Centrostephanus are continuing to expand down the east coast of Tasmania, resulting in destructive overgrazing of kelp habitats. While direct biological impacts have been well documented, economic and social implications are less understood. This project looks to define what fisheries/industries are most at risk should barrens continue to expand, and to quantify the social and economic impacts to regional areas, and Tasmania as a whole.

Ingestion of microplastics by Tasmanian shorebirds

Supervisor team:

Dr Eric Woehler

Dr Jennifer Lavers

Project description:

The project investigates the presence of microplastics in shorebirds (waders) by looking at their guano and comparing these with surrounding sediment samples and from prey species.

There are records of microplastics in invertebrates such as amphipods on which shorebirds forage, and the study will investigate whether the particles are accumulated by the birds, or pass through and are excreted. 

The project will investigate a number of species at several sites in southeast Tasmania

Skills student will develop during this project:

You will gain knowledge in avian ecology, as well as marine and pollution ecology. You will also have hands-on field and laboratory experience, and will develop skills in scientific writing and statistical analyses.

Integrated aquaculture of tropical seaweeds and lobsters

Supervisor:

Professor Catriona Hurd

This project is to evaluate the ability of seaweeds to mitigate nitrogen loading from rocks lobsters grown in aquaculture.  The major excretory product of rock lobsters is ammonium, which can be toxic in high concentrations and needs to be removed from culture systems. However, ammonium is an important source of inorganic nitrogen to seaweeds, the growth of which is typically nitrogen limited.  This research will determine the ammonium uptake ability of seaweeds under different environmental conductions (light, temperature, water flow), with a long term view of establishing an integrated rock lobster/seaweed culture system.  The work is funded by the ARC research hub for Rock Lobster culture systems (https://www.imas.utas.edu.au/research/arc-research-hub-for-commercial-development-of-rock-lobster-culture-systems).

Integrated Multi-Trophic Aquaculture – Testing the Theory in Tasmania

Supervisor team may include:

Dr Catriona Macleod

Dr Jeff Ross

Dr Scott Hadley

IMTA involves growing different species together to offset adverse interactions such as elevated nutrients. This project will test the efficiency of nutrient uptake by seaweed under different growing conditions and compare the outcomes with previously developed model outputs.

Investigating waste streams in recirculating aquaculture systems and potential utilisation of waste

Supervisory Team:

Primary supervisor: Prof Chis Carter

Co-supervisor: Dr Pollyanna Hilder (CSIRO)

Additional supervisors: TBA

Brief project description:

With the expected increase in aquaculture production to meet the growing global demand for high quality protein, there will also be an increased production of aquaculture waste requiring appropriate management. In contrast to open-water fish farms, land-based recirculation aquaculture systems (RAS) can capture all of the produced waste. Historically, the disposal of waste from RAS has been both expensive and time consuming, and with the rapidly increasing number and production tonnages of land-based RAS farms around the world, the utilisation of waste as a resource is becoming increasingly important.

This project will examine the waste stream flow in the recirculating systems of the Experimental Aquaculture Facility (EAF) at IMAS Taroona. The EAF is a partnership between IMAS and the industry companies Huon Aquaculture and Skretting, and it provides specialist research facilities to support the growth and sustainability of the salmonid industry. The saltwater recirculation systems at the EAF includes 12x 7,000 L outdoor tanks, 12x 2,500 L indoor tanks and 2x 13,000 L stock tanks. Find out more information about the EAF.

The project will identify the timing, quantity and quality of waste released into the recirculating systems by collecting and analysing water samples from different water treatment components at different times. The results can then be statistically analysed and compared between the different treatments of the core experiment at the EAF.

This project will also investigate methods of sludge reduction through experimentation with anaerobic digestion and aerobic mineralisation and evaluate potential uses for the end products of these processes. Both treatments utilise biological process to degrade organic matter with microbes converting organic rich sludge into mineralised nutrient rich fertiliser, however their mode of action differs. Aerobic mineralisation utilises an oxygen rich environment and is very effective in the reduction of solids and is faster that anaerobic digestion, however, it is also a more expensive method. Anaerobic digestion, utilising an oxygen poor environment, has the benefit of biogas production and removal of harmful pathogens. Both methods will be examined to determine the suitability of application in freshwater and saltwater salmonid RAS facilities for organic sludge reduction and utilisation.

Skills students will develop during this research project:

  • RAS management
  • Laboratory techniques
  • Statistical skills
  • Written skills

Large salmon nutrition and performance

Supervisor team may include:

Dr Louise Adams

Professor Chris Carter

Nutrition and feeding studies on harvest sized salmon are challenging without specialist experimental facilities. There are opportunities for nutrition related projects investigating aspects of feed digestibility, digestive physiology, product quality and performance under commercial conditions, aligned with large multidisciplinary experiments conducted at the EAF. Laboratory work would begin early (Feb-March) and would require travel between Hobart and Launceston during the project.

Mast cells – Fixation/staining optimization for distribution and function in teleost gills

Supervisor team may include:

Mark Adams

The teleostean mast cell/eosinophilic granule cell often plays a key role in the initiation of some inflammatory processes. However its distribution and functionality is not well resolved due its somewhat enigmatic nature. This project will investigate different fixation/staining and sectioning approaches to describe the presence and distribution in a number of teleost species.

Suitable for February or July start date.

Contact Mark Adams (Mark.Adams@utas.edu.au) for more details.

Mechanisms of nutrient uptake by Tasmanian seaweeds

Supervisor team may include:

Associate Professor Catriona Hurd

Tasmania has a globally unique and highly diverse seaweed flora with over 1000 species, most of which are unstudied in terms of their role in nitrogen and phosphorous cycling in the coastal environment. Nitrogen is the most important nutrient limiting seaweed growth and is available in two inorganic forms: nitrate and ammonium. Nitrate is considered an energetically ‘expensive’ form of nitrogen because it requires energy (from light) in order to take up and assimilate. Ammonium uptake is considered energetically ‘cheap’ as it is taken up by passive diffusion. To date, uptake rates of nitrogen and ammonium have been measured for only two species of seaweed in Tasmania and we know little of their uptake mechanisms. Phosphorous is an essential nutrient for seaweeds but uptake rates of phosphate have not been measured for any Tasmanian species.

In this honours project, you use laboratory experiments to measure the rates of nitrate, ammonium or phosphate uptake at a range of concentrations on previously un-studied Tasmanian red seaweeds. A number of projects on this general topic are available and would suit a student with a background in algal biology, temperate reef biology. Diving is useful but not essential.

Messing With Reality: Testing Heavy Metal Management Scenarios For The Derwent Using Mesocosms

Supervisor team may include:

Catriona Macleod

The aim of this project would be to test the ability of artificial habitats or constructed wetlands to remediate a broad suite of contaminants relevant to the Derwent. Depending on student interests and experience the project could i) target a particular contaminant, such as mercury, and evaluate and test alternate strategies for remediation in mesocosm trials OR ii) target a particular location (eg. MONA) and test alternate strategies for general remediation of the broad suite of contaminants in the local ecosystem.

Strategies that could be tested using mesocosm technology include but are not limited to hierarchical wetland construction with each stage designed to address a particular contamination issue and specific culture media targeting particular contaminants (these might include plant based cultures and/ or sediment based manipulations).

A key component to this project in the latter stages would be integration with landscape architects/ designers with a view to identifying ways to implement any proposed technology in real scales.

Aims: 

  1. Evaluate alternate currently available strategies for environmental remediation of either mercury OR zinc in mesocosm trials
    OR
  2. Test the efficacy of broadscale remediation techniques (constructed wetlands) to reduce the load of particular contaminants (i.e. mercury/ zinc) in Derwent hotspots.

From this project you may gain skills in: experimental design (field and laboratory), field sampling, conducting laboratory based experiments, statistical analysis, stakeholder interactions and publication of results.

Suitable for February or July start date.

Contact Catriona Macleod (Catriona.Macleod@utas.edu.au) for more details.

Modelling coral reefs to understand nutrient potential from reef fisheries

Supervisory Team:

Primary supervisor: Kirsty Nash

Co-supervisor: Julia Blanchard

Brief project description:

Fish are an important source of bioavailable micronutrients. Changes in fish community composition affects the potential supply of nutrients that society can gain from fisheries. This project will first explore the trait distributions of fish communities on reefs in Vanuatu, then use these trait distributions to develop a size and trait-based model to explore potential fisheries scenarios. This will help provide an understanding of nutrient availability today and in response to ecosystem change. The outputs of the project will help inform efforts to sustainably support the health and wellbeing of communities that rely on reef fisheries.

The project will be based on a unique dataset of reef communities located in three different management zones: fished areas, within no-take marine parks, and in tambu (temporary closures). Using data across these areas, the project will address the following questions:

  1. How does the nutritional composition of the fish community change with the species and trait composition across the different management areas?
  2. Using the data to parameterise a size and trait-based model, how well can we predict community structure and nutrient profiles?
  3. Using alternate fishing scenarios, how would we better design fishing strategies to improve nutritional outcomes in the future?

Monitoring seagrass beds using drone mapping

Supervisory Team:

Primary supervisor: Dr Myriam Lacharité

Co-supervisor(s) with affiliation and location: Dr Elisabeth Strain (Taroona), Dr Camille White (Taroona)

Intended location(s) of student: Taroona

Background and Research Aims:

In Tasmania, the health and extent of seagrass beds are monitored for potential impacts due to increased nutrient load in the water from anthropogenic sources (e.g. storm water drain, sewage outflow and aquaculture sites). This can result in changes in the spatial extent and configuration of seagrass and increases in epiphytic cover. Underwater cameras are used to monitor these changes, but their narrow spatial footprint limits their use to estimate the extent and seascape configuration of seagrass beds. Unoccupied aerial systems (UAS; e.g. drones) provide high-resolution imagery in coastal systems at relatively low costs. UAS imagery has mostly been collected in exposed intertidal systems or shallow tropical waters; however, there is growing interest for their use in temperate turbid waters subjected to sub-optimal atmospheric conditions (e.g. high cloud cover, rain, swift wind).1 When operated under optimal conditions, UAS imagery could allow a complete characterisation of bed extent in temperate shallow waters (e.g. < 5 m).

Monitoring requires robust detection limits and objective, repeatable methodology. In this project, the student will determine the feasibility of employing automated classification methods to identify seagrass beds (against non-seagrass epiphytes and macrophytes, and sediment) and delineate their spatial configuration in UAS imagery.

The student will use UAS imagery collected with a DJI Phantom 4 coupled with in-situ ground-validation data from an underwater drop-camera. Imagery will be collected under similar environmental conditions (e.g. wind speed, cloud cover, sun angle, tidal height), and at different times (twice for each site). Imagery will be collected in the vicinity of finfish aquaculture leases in southeast Tasmania: two sites near finfish leases and two sites further away from leases.

Research Aims:

  • Determine the spectral signature of seagrass, epiphytes and co-occurring macrophytes, and surrounding features from high-resolution (cm’s/pixel) orthomosaics generated with UAS imagery.
  • Use object-based image analysis to segment and classify (supervised classification) the orthomosaics into ecological classes (e.g. varying density of seagrass) to derive thematic maps useful to marine managers.
  • Determine the spectral distances between derived ecological classes and assess potential for robust automation.
  • Determine optimal environmental conditions for ongoing drone monitoring of seagrass health in southeast Tasmania.

Orange is the new Red – Evaluating a Colorimetric Indicator for Mercury Pollution

Supervisor team may include:

Dr Catriona Macleod

Dr Justin Chalker (Flinders University)

This project will test a novel approach to detect mercury contamination and bioavailability in sediments? Scientists at Flinders University have developed an innovative new polymer that is able to extract mercury from the environment. This polymer has a distinct colour change (it goes bright orange) when associated with metal uptake. We would like to improve our understanding of how this technology could be applied in environmental monitoring i.e. can this polymer provide an accurate indication of mercury distribution in the environment. This project would look to ground truth the new technology against our existing science and sediment understanding and more clearly identify how the polymer responds under different environmental conditions.

Physical Oceanography/Climate

Supervisor team may include:

Assoc Prof Neil Holbrook

Suitable for February or July start date.

Contact Assoc Prof Neil Holbrook (Neil.Holbrook@utas.edu.au) for more details.

Population growth and age dynamics of the overgrazing sea urchin Heliocidaris erythrogramma

Supervisor team may include:

Dr Scott Ling

Dr John Keane

This project will describe age and growth of the short-spined sea urchin in Tasmania.

Primary host-pathogen interactions of amoebic gill disease in Atlantic salmon

Supervisor team may include:
Mark Adams

This project will investigate the initial stages of interaction between Neoparamoeba perurans and host tissue in vivo.

Suitable for February or July start date.

Contact Mark Adams (Mark.Adams@utas.edu.au) for more details.

Regional contrasts in Tasmanian cross-shelf fish assemblages recorded from baited-underwater-video surveys

Supervision team:

Associate Professor Neville Barrett

Dr Jacquomo Monk

Baited underwater videos (BRUVs) are now in common use for surveying fish populations on reef systems around Australia. A number of surveys have now been undertaken at locations around Tasmania, but this information has yet to be synthesised to gain an understanding of the general lessons from this with respect to biogeographical patterns, ranges and depth distributions of key species, or the effectiveness of potential indicator species for long-term monitoring programs. A project is available to undertake this synthesis, as well as potentially completing an additional set of BRUV deployments on the Tasmanian west coast to fill in a current biogeographical gap in this regional coverage.

Relationships between seabed complexity and the distribution of key biota

Supervisor team may include:

Dr Neville Barrett

This project uses a comprehensive set of imagery derived from IMOS AUV deployments in Tasmanian shelf waters to examine the spatial distribution of characteristic reef associated species (e.g. particular sponges) and their relationship with significant habitat features. The work will allow future predictions of the distribution of key species based on mapped seabed geomorphology.

A range of similar projects are also available for this image analysis, including description of the spatial distribution of benthic invertebrates and algae within the Flinders Commonwealth Marine Reserve, physical drivers of benthic invertebrate structural height and complexity on deep reefs, the changing distribution of Centrostephanus barrens in eastern Tasmanian waters.

Suitable for February or July start date.

Contact Dr Neville Barrett (neville.barrett@utas.edu.au) for more details.

Reproductive dynamics of the sea urchin Heliocidaris erythrogramma: implications for roe harvest and kelp bed overgrazing

Supervisor team may include:

Dr Scott Ling

Dr John Keane

This project will describe reproductive biology of the short-spined sea urchin in Tasmania.

Responses of seaweeds (macroalgae) to ocean acidification

Supervisor team may include:

Associate Professor Catriona Hurd

Ocean acidification is predicted to cause widespread modification of marine ecosystems in a future high CO2 ocean.  Fleshy macroalgae (e.g. kelp) dominate temperate rocky reefs worldwide, and while it has been predicted that they will benefit from ocean acidification but to date there is little evidence to support this hypothesis.  Unlike terrestrial plants that use only CO2, macroalgae can utilise either CO2 or bicarbonate (HCO3-) that is dissolved in seawater for photosynthesis.  However, in Tasmania we have a globally unique coastal system that has a substantial number (80%) of species that can use only CO2 in photosynthesis (Cornwall et al. 2015).  In this honours project, you will examine the growth and physiological responses of Tasmanian red seaweeds to CO2 fertilization using a state-of-the-art ocean acidification simulator available in Hurd’s laboratory.

A number of projects on this general topic are available and would suit a student with a background in algal biology, plant physiology and/or temperate reef biology.  Diving is useful but not essential.

Responses of seaweeds to the interactive effects of nitrogen supply and ocean acidification

Supervisor team may include:

Associate Professor Catriona Hurd

Globally, levels of dissolved CO2 in seawater are increasing, termed ocean acidification (OA).  Locally, levels of inorganic nitrogen are increasing due to altered land use (e.g. farming) or more intensive aquaculture.  However, we know little on the interactive effects of both increasing CO2 and nitrogen on seaweeds, which form the base of coastal ecosystems.  Recent work has shown for the common green seaweed, Ulva (sea lettuce) that nitrogen is more important than CO2 in controlling seaweed growth and photosynthesis (Rautenberger et al. 2015, Reidenbach et al (2017).  However, Tasmania has a globally unique and highly diverse seaweed flora with over 1000 species, most of which are unstudied in terms of their physiology and response to global and local anthropogenic change. In this honours project, you will examine the interactive effects of nitrogen and CO2 fertilization on previously un-studied Tasmanian red seaweeds using a state-of-the-art ocean acidification simulator available in Hurd’s laboratory.

A number of projects on this general topic are available and would suit a student with a background in algal biology, temperate reef biology.  Diving is useful but not essential.

Seaweed Aquaculture: managing biofouling

Supervisory Team:

Primary supervisor: Assoc Prof Catriona Macleod

Co-supervisor: Prof Catriona Hurd

Additional supervisors: Dr Craig Sanderson, Dr Camille White/ Dr Beth Strain depending on availability

Brief project description:

The Seaweed Solutions CRC has an opportunity for an honours/ masters student to explore a critical issue for industry development. Biofouling of cultured seaweed reduces productivity and depending on species composition and quantity can create broader environmental issues. There is potential for 2 complementary Honours/ masters research projects to examine:

  1. The nature of seaweed biofouling communities, and the environmental factors influencing settlement and density (i.e. light, depth, temperature and timing/ season).
  2. Potential management strategies. This may include investigation of non-intervention (e.g. timing of out planting, or positioning of plants on site) and intervention (i.e. physical removal, barrier mechanisms) approaches, and how these might affect product quality and management strategies.

Skills students will develop during this research project:

  • Project management (planning, development and implementation)
  • Key research skills for both lab and field research
    • skills and risk assessments
    • specific lab skills in topic areas (e.g. taxonomy, nutrient analysis)
    • experimental design and management
  • Data analysis and reporting
  • Leadership and team participation skills
  • Science communication (both written and verbal)
  • Greater understanding of important ecological concepts as well as gaining insights into critical marine resource management issues

Sediment recovery – A quantitative assessment of how faunal activity influences recovery response in Macquarie Harbour and analysis of key risk factors.

Supervisor team may include:

Dr Catriona Macleod

Dr Jeff Ross

Adam Davey

Lab based assessment of the functional response of sediments in Macquarie Harbour to key species.

Southern Ocean physical oceanography

Supervisory Team:

Primary supervisor: Dr Amelie Meyer

Co-supervisor: Dr Christopher Chapman (CSIRO Hobart)

Additional supervisors: N/A

Brief project description:

Characteristics and trends of fronts and meanders south of Tasmania.

The Southern Ocean is a key component of the global climate system absorbing a large fraction of anthropogenic heat and carbon. It has one of the strongest current system in the world, the Antarctic Circumpolar Current, composed of a series of fronts, meanders, and jets. These fronts, jets and meanders in the Southern Ocean have a large impact on local ocean dynamics and for the entire climate system. They influence exchanges between the ocean, atmosphere, and cryosphere in several ways: for example, fronts are sites of enhanced exchange between deep and surface waters through upwelling and subduction; Jets drive most of the ACC transport and act as a barrier to horizontal mixing; and fronts and meanders are key to the generation of mesoscale eddies and filaments.

The impact of climate change on the structure and characteristics of fronts and meanders in the SO is still under investigation. A key discussion in the field is around how to best define and identify fronts and meanders in the Southern Ocean. More recent methods based on local definitions and presence probability show trends in the shape and structure of the Agulhas-Kerguelen standing meander. Are these trends limited to the Agulhas-Kerguelen standing meander or do they exist elsewhere in the Southern Ocean?

This project aims at characterizing standing meanders and their trends in the Southern Ocean. This will be done by applying methods developed for the Agulhas-Kerguelen standing meander to other standing meanders in the Southern Ocean, with a focus for the region south of Tasmania.

Skills students will develop during this research project:

Research skills: applying scientific method to a problem; Southern Ocean dynamics knowledge; interplay of processes at various spatial and temporal scales; statistical analysis.

Analytical skills: analysing and visualizing data in Matlab; Synthesizing information; building conceptual explanations.

Communications skills: Presenting complex problems clearly; using scientific language and reporting methods; writing up a research project; designing scientific presentations.

Subantarctic response to rapid climate change: A paleo perspective

Supervision team may include:

Associate Professor Zanna Chase,  Dr Axel Durand and PhD student Harris Anderson

Ocean samplingThis project aims to determine how the Southern Ocean responds to abrupt climate change. Rapid warming events of the last ice age provide an analogue to human caused warming. This project focuses on the Subantarctic sector of the Southern Ocean, south of Tasmania. You will use geochemical measurements in marine sediment cores to reconstruct ocean productivity and dust deposition across the last glacial cycle, focusing in particular on the period during the last ice age called Marine Isotope Stage 3. During this time, the northern hemisphere experienced repeated episodes of rapid warming (up to 10 degrees in 100 years) while southern hemisphere ice cores reveal more gradual warming during peak northern hemisphere cooling. These events were associated with increases in atmospheric CO2. The role of ocean biogeochemical processes, including iron fertilization of Subantarctic waters, is not known. Results from this project will be used to determine the nature, timing and drivers of the biological response to rapid climate change.

This project will involve a significant component of laboratory work in geochemistry (sediment acid digestion, column chemistry and analysis by ICP-MS). You will need to be comfortable working in a lab, and be familiar with basic concepts in analytical chemistry.

The spawning behaviour of Spotted Handfish in the Derwent Estuary

Supervisor team may include:

Dr Neville Barrett

This project examines the extent that handfish utilise artificial vs natural spawning substrates, and the success of egg development through to hatching on each. A handfish guard eggs over this period, both eggs and adult fish are particularly vulnerable over this stage. Using gopros and visual observations, behavioural interactions will be described, and recruitment success determined.

Suitable for July start date.

Contact Dr Neville Barrett (neville.barrett@utas.edu.au) for more details.

Thermal physiology of Bay lobster (Thenus australiensis); defining temperature optimum and tolerance throughout juvenile ontogeny

Supervisory Team:

Primary supervisor: A/Prof. Quinn Fitzgibbon

Co-supervisor: Dr. Andrew Trotter

Additional supervisors: Prof. Greg Smith

Brief project description:

Recently, IMAS was awarded a prestigious Industrial Transformation Research Hub (ITRH) by the Australian Research Council (ARC) to undertake research on Sustainable Onshore Lobster Aquaculture.

The program will develop unique onshore aquaculture systems to facilitate the cost effective and sustainable production of lobsters. A relatively new species of interest to the program is the Bay or Slipper Lobster, Thenus australiensis, which exhibits promising attributes for aquaculture including a short larval duration, rapid growth and compatibility for high density culture. However, this species is new to onshore aquaculture there is a particular lack of knowledge of the environmental requirements and tolerances levels. Temperature is possibility the most influential abiotic factor effecting performance of ectotherms due to its strong influence on the rates of physiological functions.

This project aims to define the temperature optimum for Bay lobsters throughout juvenile ontogeny and its interactions with nutrition, behaviour and health. Assessment of thermal performance will be assessed through both traditional culture experimentation and physiological assessments including measurements of respiratory metabolism (oxygen consumption, heart rate) and nutritional factors (feed intake, biochemical analysis). These projects provide the opportunity to join a large and well-funded research program at the cutting edge of lobster aquaculture research and will provide training in a wide range of advanced aquaculture and analytical techniques.

Two decades of recreational licensing – what has changed and why?

Supervisor team may include:

Dr Jeremy Lyle

Dr Sean Tracey

Marine recreational licences are required for a range of fishing activities in Tasmania. The databases provide an informative insight into the characteristic of those interested in each of the specific fishing methods, including age and area of residence. Not only does this data reveal interesting patterns in the changing demographics of fishing, for example a transition from diving to potting for lobster with age, but also variability in licensing linked to changing management and resource availability.

Using Electrolysed Oxidising (EO) water as a pre-treatment sanitiser for chilled fish stored on ice

Supervisor:

Mike Williams

(Please contact the supervisor for further information)

Utilising towed-video contrasts in/out of offshore marine parks to assess the possible impacts of trawling on benthic invertebrate assemblages

Supervision team:

Associate Professor Neville Barrett

Dr Jacquomo Monk

The potential influence of trawling in shelf waters on benthic fauna had been estimated by model-based approaches but never examined empirically in temperate Australia. Current IMAS surveys in/out of the Beagle Marine Park in Bass Strait (an area closed to trawling for the last 10 years) utilising towed-video, offer an opportunity to quantify the nature and extent of soft-sediment epi-benthic fauna (sponges, ascideans, corals etc) in this region for the first time. This will allow a contrast to be made between the MPA and adjacent fished areas, informing the extent to which trawling may have influenced (or not) this assemblage.

Utility of ROV’s (remote operated vehicles) for surveying reef fish assemblages below diving depths

Supervisor team may include:

Dr Neville Barrett

This project utilises a ROV (Seabotix LVB300) to be deployed at a range of test locations in eastern Tasmania to both determine the effectiveness of ROV's for reef fish surveys, and the appropriate survey design to yield quantitatively robust results for monitoring programs. Surveys may focus on MPAs (State and Commonwealth).

Suitable for February or July start date.

Contact Dr Neville Barrett (neville.barrett@utas.edu.au) for more details.

Validating a new proxy for iron fertilization in the Southern Ocean

Supervisor:

Dr Taryn Noble

Project Description:

The input and dissolution of continental material to high nutrient surface waters of the Southern Ocean plays an important role in biogeochemical cycling of carbon because it alleviates iron limitation and stimulates phytoplankton growth. In remote subantarctic regions dust is an important source of dissolved iron, but close to Antarctica, dissolved iron sources include melting sea ice, icebergs calved from glaciers, and upwelled deep waters.

The Antarctic Ice Sheet is experiencing rapid changes in response to anthropogenic climate warming. Melting ice shelves and glacier retreat will increase the input of freshwater and dissolved continental material to the surface ocean, but the biological response to these changes (and therefore impact on the global carbon cycle) is unknown. However, we can study the biological and chemical response to past changes in ice sheet retreat recorded in ocean sediments to improve our understanding of how the system might change in the future.

The aim of this Honours project is to test the reliability of a geochemical method (Robinson et al. 2008) for quantifying the dissolved iron flux along the continental margin of East Antarctica. This method uniquely targets the input of dissolved material, rather than the input of total continental material. The distinction is biologically important, because phytoplankton take up dissolved iron from seawater.

Chemical leaching experiments will be carried out on surface seafloor sediments, which preserve the most recent period of sediment deposition. Two isotopes of thorium will be measured in the leachates, Th-232 which only enters the ocean from continental inputs, and Th-230 which is produced mainly from the decay of U-234 dissolved in seawater. Thorium is very insoluble in seawater and as is dissolves from continental material it rapidly adsorbs to the surface of particles, making it an excellent tracer of dissolved components. 

The leaching is designed to recover only the Th that is adsorbed to the sediment particles, which should represent the 232Th/230Th ratio in the overlying seawater. The results of the leaching experiments will be compared to existing measurements of the dissolved 232Th/230Th in the overlying water column in order to assess the reliability of this method.

What’s the big deal with big fish?

Supervision team:

Dr Karen Alexander

Dr Asta Audzijonyte

Dr Ingrid van Putten

Increasing scientific evidence demonstrates the importance of big individuals in marine animal populations. They include fish, rock lobsters, abalone, and many other species that traditionally are valued (economically and otherwise) by humans. Big individuals often have disproportionally large input for reproduction, better viability of offspring and they also play a key role in ecosystem structure and function. However, in many cases the biggest individuals are also the most desired by humans for instrumental and intrinsic reasons. Commercial fishers may target large fish because the economic returns are higher and because fishing regulations typically protect small but not large individuals. Recreational fishers may have other reasons driving their desire to catch big fish, and catching the biggest fish is often formalised in fishing competitions and trophies. The desirability of big fish has deep roots in our history, where a big trophy proved the harvesters powers and provided a lot of food for the village. However, in some traditional societies the biggest individuals were voluntarily protected.

This project will be undertaken through the Centre for Marine Socioecology and will explore the history of perceptions about large fish and other marine organisms in traditional and modern societies around the world. What can history and cultural traditions tell us about our social norms and attitudes related to the size of fish? How do we perceive the size of fish in Australia and how does this compare to perceptions elsewhere? How do our attitudes, and descriptive and injunctive social norms shape our behaviour? Does the way a society perceives the ecological and social role of fish size conducive or hindering to sustainability? If societal attitudes and social norms are hindering sustainability outcomes are there examples of how we can change these attitudes? How can science influence human behaviour for the better and what are the most efficient ways of communication and engagement?

Authorised by the Executive Director, Institute for Marine and Antarctic Studies
March 24, 2020