As increasingly greater demands are made on marine food resources in Australia’s EEZ and throughout the rest of the world’s oceans, the need to develop new technologies to improve food supply and aid with the management of these resources also increases. Authorities need to have a clear understanding of the complex dynamics underlying populations of marine species - the connections between various populations, their patterns of dispersal and other vital issues - in order to devise sound management plans. The development of Australia’s mariculture industry is also key to preserving our wild populations of important marine food sources.

Since 1989, the Australian Institute of Marine Science has been helping to develop new technologies to improve the supply of marine food resources and to better understand the impact of aquaculture and fishing on natural resources.

That research has expanded to include the use of molecular science and genetic technology to help gain a clearer understanding of the degree to which marine populations and communities are connected (i.e. the extent to which they serve as recruits for each other), and an understanding as to whether particular locations possess or give rise to biological diversity.

Mariculture research at AIMS focuses on the reproduction and genetics of a variety of tropical species important to the mariculture industry (i.e. prawns, beche-de-mer and tropical molluscs, such as pearl oysters). The giant tiger prawn, Penaeus monodon, has played a principle role in this research.

Prawn mariculture has emerged as a significant and developing industry in northern Australia, and is now valued at more than A $35 million. P. monodon is central to this production. If through the research at AIMS the mean size of prawns can be improved by 5 per cent per annum, the Australian industry will be well placed to capture more of the lucrative Asian market. Even if the increased size of prawns allows a capture of only 5 per cent of the Asian market, the value to the Australian industry would be an additional $15 million annually.

The goals of the Marine Biotechnology Project are to domesticate marine species, manipulate reproduction, genetically improve strains, and determine the genetic structure of wild populations. AIMS scientists are using advanced genome and proteome research to achieve these goals, applying innovative approaches to gain new insight into prawn reproduction and finding surprising information as to the dispersal and connections between populations of marine species. The genome and proteome research has given AIMS scientists information on a number of key molecules involved in prawn reproduction. Their genetic population work has revealed that little correlation exists between patterns of genetic diversity within taxa and present day ocean circulation, raising fundamental questions concerning the origin and maintenance of marine biodiversity.

The Marine Biotechnology Project consists of four sub-projects which focus on different and complementary aspects of genetic and mariculture research.

Physiological controls in marine species - The control of the reproductive process is essential for the development of domesticated strains of marine organisms. To date, prawns have been induced to spawn by removing part or all of the eyestalk. Although partially effective, it is a crude, costly and essentially non-sustainable method of rearing young. One of the goals of this project is to determine the physiologically active compounds arising from the eyestalk and to determine their role in ovarian maturation and spawning.

Molecular genetics of reproduction and development - While the previous sub-project focuses on the physiologically active compounds controlling reproduction, and isolates those products found in reproductively active individuals and not in non-reproductive individuals, this sub-project takes a slightly different angle. Researchers in this sub-project will look at ways in which to isolate and clone messenger RNAs which may encode proteins involved in the reproductive process.

Selective breeding - Using methods developed by AIMS scientists to artificially mate and rear large numbers of prawn families, this sub-project focuses on generating a population of prawn families to form the basis of a selective breeding program designed to pinpoint characteristics of ecological importance.

Genetic structure of populations - Earlier genetic research by AIMS scientists into the nature of larval dispersal and the connections between natural populations of marine species has involved comparing animals with longer larval lives (such as crown-of-thorns starfish and Linckia seastars, various giant clam species, zoanthids and coral groups) with animals which have shorter larval life spans (Trochus and various coral species). Researchers are now concentrating on those same taxa to develop a range of molecular markers using mitochodrial DNA, highly variable DNA regions such as introns and microsatellite DNA, and more conserved gene regions, to obtain some information on the relative time scales of dispersal events.

Work on squid, which are very difficult to tell apart by looking at them, has shown that our major squid fisheries in northern Australia are composed, not of the two species which were thought to be there, but by four species new to science. This finding is important for management of this fishery in Australia and Southeast Asia.

This research will be at the cutting edge of work on the genetic structure of natural populations. It should provide scientists with a means to link events occurring on ecological timescales with those occurring on biogeographical and evolutionary timescales.

All four of these sub-projects are addressing critical aspects of reproduction and genetics necessary for the sustainable development of the Australian mariculture industry and the management of our marine resources. The research will lead to improved understanding of the fundamental processes regulating reproduction in marine species and those controlling genetic diversity in the wild - information vital to helping Australia’s mariculture industry and to assisting marine management authorities in meeting the demands of the future.