Predicting species size-distributions

Properties and applications of aquatic species size-distributions

Degree type

PhD

Closing date

18 July 2022

Campus

Hobart

Citizenship requirement

Domestic/International

Scholarship

$28,854pa for 3.5 years

About the research project

Natural populations consist of individuals that at any given time vary in their body size. The shape of body size distribution in a population can inform us about population status and species properties, but most analyses to date are based on theoretical predictions without extensive validations with empirical data. Many size-based ecological and fisheries models assume that the maximum body size of a species is fixed in space and time, yet empirical data suggests that species body sizes vary extensively across temperature gradients. Moreover, experimental evidence suggests that that intra-specific body size distributions could be described with a consistent shape, but conditions under which this occurs remain unclear. This project aims to investigate statistical properties of intra-specific body size distributions in fishes and other aquatic ectotherms using a extensive global and regional empirical datasets across ecological and human impact gradients (underwater visual surveys, fisheries surveys, citizen science, angler reports, and others).

The project has three main objectives:

1) Identify and quantify intra-specific body-size distributions using empirical datasets of fishes and aquatic invertebrates (copepods, rotifers) that span ecological and harvesting gradients. Assess whether temperature and harvesting induce consistent responses in the properties of size-distributions (e.g., mean, variance, skew).

2) Conduct population and community-level simulations to explore species physiological parameters and ecological conditions under which theoretically predicted size distributions are consistent with empirically observed distributions, assessed in objective 1.

3) Develop quantitative tools that take observed body-size distributions when the number of observations is limited and estimate population status. Apply the tools to citizen science-based data sets (e.g., angler data, natural history observations) that are becoming increasingly abundant with advances in detection and monitoring technology.

Primary Supervisor

Meet Dr Asta Audzijonyte

Funding

The successful applicant will receive a scholarship which provides:

  • a living allowance stipend of $28,854 per annum (2022 rate, indexed annually) for 3.5 years
  • a relocation allowance of up to $2,000
  • a tuition fees offset covering the cost of tuition fees for up to four years (domestic applicants only)

There is a top-up scholarship of $5,000 per annum (not indexed) for 3.5 years, with no extension, funded by Quantitative Marine Sciences (QMS) that will be considered for an outstanding applicant.

For this project, QMS will also cover the successful international applicant's single Overseas Health Cover (OSHC).

If successful, international applicants will receive a University of Tasmania Fees Offset for up to four years.

As part of the application process you may indicate if you do not wish to be considered for scholarship funding.

Eligibility

Applicants should review the Higher Degree by Research minimum entry requirements.

Additional eligibility criteria specific to this project/scholarship:

  • Applicants must be able to undertake the project on-campus.

Selection Criteria

The project is competitively assessed and awarded.  Selection is based on academic merit and suitability to the project as determined by the College.

Additional essential selection criteria specific to this project:

  • Demonstrated skills or strong interest in quantitative data analysis and size based modelling.
  • Strong quantitative and statistical skills.
  • Demonstrated experience in statistical methods.
  • Strong experience in using quantitative methods in R.
  • Ambition to work with large datasets.
  • Demonstrated proficiency in written and verbal English language.

Additional desirable selection criteria specific to this project:

  • First-author publication (submitted, or close to submission) on a related topic.

Application process

There is a three-step application process:

  1. Select your project, and check you meet the eligibility and selection criteria;
  2. Contact the Primary Supervisor, Dr Asta Audzijonyte to discuss your suitability and the project's requirements; and
  3. Submit an application by the closing date listed above.
    • Copy and paste the title of the project from this advertisement into your application. If you don’t correctly do this your application may be rejected.
    • As part of your application, you will be required to submit a covering letter, a CV including 2 x referees and your project research proposal.

Following the application closing date applications will be assessed within the College. Applicants should expect to receive notification of the outcome by email by the advertised outcome date.

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