Buoyancy of Atlantic bluefin tuna Thunnus thynnus eggs obtained from captive broodstock spontaneous spawning events

Abstract

One way to alleviate the pressure on the wild fishery of the Atlantic bluefin tuna (BFT) and aid in its conservation could be its domestication and the development of a self-sustained industry to rear the larvae and produce fingerlings in captive conditions for further grow-out. The Spanish Institute of Oceanography (IEO) is carrying out several research projects on this target for the last 12 years.

No one has yet measured the vertical distribution and the in situ buoyancy of bluefin tuna eggs in any of its spawning areas in the world (Mac Kenzie and Mariani, 2012). In the present study the density of bluefin tuna eggs has been measured, comparing it with those of other fish species, particularly Atlantic bonito. We have estimated the speed by which BFT eggs rise to the surface to get a better idea of the potential loss of spawned eggs dragged by the currents out of the cage.