Project Leader: John Benzie

Understanding Australia’s marine biodiversity is one of the fundamental challenges of modern marine science. Advanced biotechnology will ensure preservation of wild populations, yet enable marine species to be cultured as a major food source.

This project uses molecular science and genetic techniques to investigate fundamental questions in marine biology and to improve the artificial culture of marine species. It addresses critical questions of reproduction and genetics of cultured species and investigates the extent and nature of genetic diversity in wild marine populations.

The project concentrates on an understanding of the molecular regulation of development, growth, and reproduction of the giant tiger prawn Penaeus monodon, the species most commonly farmed in Australia and South-East Asia and one which has excellent prospects for further industry growth in Australia. This work involves a blend of molecular genetics and endocrinology integrated with applied husbandry to obtain efficient closed life cycle reproduction in P. monodon. Selective breeding in combination with the use of molecular markers will enable development of superior strains and detection of particularly useful genes. Work is also being done on the genetics of pearl oysters, giant clams and beche-de-mer, as well as on the reproduction of barramundi.

Work with wild populations of marine species is utilising genetic markers to identify cryptic species, to determine geographic boundaries, to trace dispersal and to map the connectivity of wild populations. The work has relevance to resource management, testing of hypotheses of biogeography and evolution, testing predictions of dispersal based on hydrodynamic models, and developing molecular tools to more rapidly assess marine genetic diversity.

Goals

• to enhance understanding of the physiological and genetic control of prawn reproduction;
• to develop methods for commercial breeding of prawns;
• to utilise biotechnologies to investigate reproductive processes in fish and other marine organisms;
• to better understand the nature of larval dispersal and genetic connectivity in natural populations;
• to improve understanding of marine biodiversity.

Physiological controls in marine species (Leader: Mike Hall)

This study is designed to improve understanding of physiological and hormonal mechanisms for the regulation of reproduction and development of cultured giant tiger prawns.

Molecular genetics of reproduction and development (Leader: Kate Wilson)

Genetic mechanisms underlying early development, growth and reproduction in marine organisms are investigated through determining the key genes involved in these processes. This work complements the physiological study by isolating and cloning messenger RNAs which may encode proteins involved in the reproductive process.

Selective breeding (Leader: John Benzie)

Methods have been developed over the last five years to artificially mate and rear large numbers of prawn families. Spawners selected from these families are being cross-bred to improve traits like growth and disease resistance. In-vitro techniques for egg manipulation and ploidy manipulation will assist the development of highly inbred lines that should speed the identification of molecular controls of key traits.

Genetic structure of populations (Leader: John Benzie)

This study is designed to improve understanding of the origin and maintenance of marine biodiversity, the nature of dispersal and connectivity of natural populations of marine organisms, and the potential impact of mariculture releases. It achieves this by documenting patterns of genetic diversity in selected species in space and time and by testing specific hydrodynamic or biogeographical hypotheses of dispersal.

Human Impacts on Coastal Marine Ecology

• genetic diversity of mangroves.

Sustaining Coral Reefs

• dispersal patterns of crown-of-thorns starfish.

Predicting the Coastal Marine Environment

• predictive spatial models for gene flow.

Links with other organisations

CRC for the Great Barrier Reef World Heritage Area, CRC for Aquaculture, South Australian Research and Development Institute, James Cook University, CSIRO Australian Animal Health Laboratories, CSIRO Marine, Queensland Department of Primary Industries as well as with eight overseas universities and research organisations within the United States, Netherlands, UK, Israel, Indonesia, French Polynesia and South Africa.

Links with strategic directions

1998/99 funding base
Total budget $1,380,000 (65% appropriation; 35% external)

Major external sources:
CRC for Aquaculture
Fisheries Research and Development Corporation (FRDC)
AusAID

Scientific staff

Research scientists: John Benzie, Mike Hall, Kate Wilson.

Scientific support: Beth Ballment, Don Booth, Matt Kenway, Rebecca Mastro, Chris Pacey, Lesa Peplow, Matthew Salmon, Carolyn Smith, Jennie Swan, Rick Willis (50%).

Postdoctoral: Marlene Davey, Jürgen Otto, Sven Uthicke, Lynne van Herwerden.

Postgraduates: Amanda Brooker, Bernadine Jeffrey, Cecile Fayos, Carol Fraser.