These animations detail the dynamics of preferred feeding habitat of the Atlantic bluefin tuna developed by the EC-Joint Research Centre with, as an overlay, the locations of bluefin tunas equipped with an electronic tag. These examples demonstrate the performance of the habitat modelling since the tag locations were not used to calibrate the model. It furthermore provides key information on the species behaviour and distribution to be used to improve the stock estimate and define sustainable fishing quotas.
This electronic tag was deployed by AZTI (Spain) on a juvenile bluefin tuna for two years. This exceptionally-long tag allowed to follow the fish migration between its summer feeding ground in the Bay of Biscay (NE Atlantic) and its winter exploration for new habitat in the Azores area on the first year and in the Canadian part of the Gulf Stream on the second year. The fish would certainly have fully crossed the Atlantic on the third year as the adults usually do following the Gulf Stream that acts as an ecological bridge.
Two electronic tags were deployed by IFREMER (France) during summer in the Gulf of Lions for one year on young adult bluefin tunas. This animation shows that both fish follow the seasonal habitat contraction and expansion as they spread in the Mediterranean Sea in winter and spring while they come back to the Gulf of Lions in summer, in the most important feeding ground as emphasized by the habitat prediction.