Propagation of tuna is an emerging aquaculture activity that is being pursued in Australia, USA, Japan and Europe. Controlled spawning of captive tuna broodstock requires considerable infrastructure and the availability of the land based tank facility at GRIM provides potential for ongoing R&D collaboration to address issues confronting hatchery production of tuna fingerlings as a precursor to commercial sea cage farming in Indonesia and Australia.
The project has been amended to include the involvement of Aquaculture Development Unit (ADU), Challenger TAFE, Fremantle, Western Australia. This amendment brings greater aquaculture expertise into the project and also provides linkages to additional potential Australian industry beneficiaries.
During November 2008 the use of larger fishing vessel to assist the capture of greater numbers of YFT broodstock has been investigated. The 40 GT tuna long lining vessel 'Kapal' was chartered for 25 days from a fishing company based in Benoa, Bali. This vessel was equipped with five onboard tanks (2m x 2m x 2 m) to hold captured fish. During the charter period, the vessel was operated as a 'mother' ship with fishing conducted from a smaller 'tender' vessel operated by GRIM staff. When 1 - 3 fish were captured these were transferred to the larger vessel allowing fishing to continue until 10 -12 fish had been captured before returning to GRIM. Although 84 fish were captured using this approach the survival of fish following transportation was low with only 13 fish transferred into land based holding tanks.
During February and March 2009, visits to GRIM by scientists from SARDI and Challenger TAFE and industry (Latitude Fisheries) have reviewed project progress and identified improved fishing and fish transportation methods that are currently being trialled. During May 2009, ADU officer, Rob Michael, visited GRIM for 5 days to identify and trial different fishing methods to improve broodstock capture. Broodstock capture has since increased with a total of 16 new fish currently being on-grown at GRIM.
From 8th until 20th June 2009, GRIM project scientist, Jhon Hutapea and Dr Gavin Partridge (ADU) attended the '7th Annual Workshop on Physiology and Aquaculture of pelagics with emphasis on reproduction and early developmental stages of yellowfin Tuna, Thunnus albacares', held at the Inter- American Tropical Tuna Commission, Achotines Laboratory, Republic of Panama. During this workshop larval rearing trials were conducted and discussions were held to identify possible improvements to assist broodstock capture, transport and husbandry. A report on this workshop will be prepared including recommendations.
Opportunities are being developed for ongoing International collaborative research on yellowfin tuna larval rearing that will be possible as new broodstock become mature in 2010.