Atlantic Tuna Bred in Captivity

Beginning on June 29th 2009, a captive-reared broodstock of Atlantic bluefin tuna maintained at the sea cage facilities of the SELFDOTT project partner Tuna Graso, of the Ricardo Fuentes Group in Cartagena, Spain, began spawning after being implanted with a reproductive hormone delivery-system.

The fish spawned daily afterwards, producing a total of 140 million eggs by July 17th, with a daily maximum of 34 million eggs (3rd of July).

A second captive-reared broodstock of Atlantic bluefin tuna maintained at the sea cage facilities of Mare Nostrum, Puglia, Italy, also began spawning 3 days after hormone delivery system implantation (30th June), producing a total of 46 million eggs over the course of two weeks.

The eggs produced at the two sites were sent to research hatcheries in Spain, France, Italy, Malta, Greece and Israel to commence for the first time the research on the larval rearing of this magnificent and unique marine fish.

The successful spawning in two different locations in the Mediterranean Sea, using the same broodstock management and spawning induction methods is a major success and an important step towards the domestication of the Atlantic bluefin tuna in the Mediterranean region, thus contributing to the conservation of the heavily exploited and seriously threatened wild stocks.

A third broodstock maintained at the sea cage facilities of Malta Fish Farming Ltd (Malta), was shown to have a significant improvement in gonad size and reproductive maturity status in response to a diet formulated specifically for tuna broodstocks by the Malta Centre for Fisheries Sciences (Malta).

However, no fertilized eggs were collected from this stock, probably due to high currents at the rearing site, pointing to the risks involved in maintaining broodstock in sea cages and the need for the development of a dedicated land-based broodstock facility for the Atlantic bluefin tuna.