World Aquaculture 2023

May 29 - June 1, 2023

Darwin, Northern Territory, Australia

GROWTH, SURVIVAL AND SHELL SHAPE IN BLACKLIP ROCK OYSTER Saccostrea echinata/ lineage J CULTURED UNDER DIFFERENT STOCKING DENSITIES AND TIDAL ZONE LOCATIONS IN TROPICAL AUSTRALIA

Brien Roberts*| Mitchell Beagley | Bunug Galaminda | Brando Westley | Matthew Osborne | Samantha Nowland

Darwin Aquaculture Centre, Channel Island

Department of Industry, Tourism and Trade

Northern Territory Government of Australia

GPO Box 3000, Darwin NT 0801 nt.gov.au

Brien.roberts@nt.gov.au

 

 



The Blacklip rock oyster Saccostrea echinata has considerable potential to support new aquaculture development throughout the tropical Asia Pacific region. However, as with the tropical rock oyster industry more broadly, production remains in its infancy, and there is a lack of fundamental information relating to many aspects of the biology of S. echinata. Further, the suitability of farming techniques developed for bivalves in temperate growing regions remains unknown and untested in the tropics. Here, I will discuss the results of the first completed growout trial for S. echinata, undertaken at a pilot farm at South Goulburn Island, Northern Territory, Australia. An intertidal longline system was stocked with hatchery-produced spat (cultivated at Darwin Aquaculture Centre, Northern Territory) during February 2020. The aims of the trial were 1) to collect baseline information on survival, growth rates, and time to attain market size, and 2) to assess the effects of tidal zone location and stocking density on growth and morphometry of S. echinata. Oysters attained market size (70 mm DVM) in approximately 2.5 years. Shell morphology was significantly affected by stocking density, with increased abrasion due to wave action at lower densities producing a deeper, wider shell. Likewise, reduced immersion periods in the higher tidal zone resulted in reduced feeding opportunities and promoted a deeper, shorter shell. The results of this study are discussed with regard to future prospects, challenges and research opportunities for tropical rock oyster production