Bluefin tuna larvae (Photo Credit: TRANSDOTT)
First bluefin tuna eggs arrive at EU hatcheries
Friday, June 21, 2013, 23:40 (GMT + 9)
Bluefin tuna larval rearing trials are starting in Spain, Israel and Malta within the framework of the EU 7th Framework Research Project TRANSDOTT.
Eggs are being sent from Malta by the partners responsible for broodstock management and egg collection, namely the Malta Aquaculture Research Centre (MAR) and MFF Ltd (Malta Fish Farming Ltd) with the assistance of members from IOLR/NCM (Israel) and the University of the Düsseldorf (Germany).
The bluefin tuna eggs are being collected from the broodstock cages of the EU TRANSDOTT project off the south east coast of Malta, where the bluefin tuna are spawning naturally within the cages.
MAR has also recently reached an agreement for collaboration with Mr Wan-Kyu Park from the Korea Marine Fish Hatchery Association, who is in Malta collecting eggs from tuna cages anchored off the north east coast, through AJD Tuna Ltd. Their novel egg collection method contrasts with the traditional PVC curtain egg collector used in previous DOTT projects and uses a “trawl-net type” egg collector design that makes good use of Malta's currents to collect eggs from outside the broodstock cage rather than by collecting eggs with the Japanese traditional method of using a curtain inside the net around the cage surface.
The TRANSDOTT partners are studying the collection of eggs by both methods as currents around the Maltese islands have caused problems with egg collection in past years.
Although the “trawl-net type” egg collector is superior to the PVC curtain for tuna egg collection from Maltese waters, it has its disadvantages: It only collects a small percentage of the eggs produced, so a much larger fish biomass is required to get a sufficient number of eggs.
The TRANSDOTT partners continue to fine-tune and improve their egg collection methods by incorporating the PVC curtain design with the Korean system.
In the meantime, Malta has shipped approximately 1,200,000 eggs to supply a ARDAG (SME hatchery) and IOLR-NCM research facility based in the Eilat, Israel through Lufthansa air-freight. Further transportation has also been initiated to the premises of Futuna Blue Espaňa S.L. in their purpose-built land-based facilities for larval rearing and fingerling production research at El Puerto de Santa Maria near Cadiz, Spain. Fertilization rates have been very good and in previous years hatching rates have approached over 90 per cent. Dr Robert Vassallo-Agius (MAR) said they anticipate much high spawning rates within the next weeks where up to 100 million eggs per day can be collected.
Tuna eggs normally require about 33 hours from spawning to hatching and eggs are cooled to 22 °C to retard hatching until they have arrived at their destination.
Similar operations are being carried out in other national programmes at the facilities of IEO in Mazarron, Murcia Spain. The aim of TRANSDOTT to translate research results into commercial operations will take another step forward in the production of viable fingerlings we hope in the weeks to come.
The notion of eggs on demand is now becoming a viable alternative for the industry. A new commercial entity TunaTech is to be launched in the near future to provide custom services to the developing sustainable aquaculture of Atlantic bluefin tuna and have already supplied GnRHa implant carrier technology to US investors in Kali Tuna in Croatia and a number of other European aquaculture centres.