Are there any records of bigeye tuna (Thunnus Obesus) and albacore (Thunnus Alalunga) in the Gulf of Cádiz, in Spain, and the Algarve, in Portugal?
Francisco from Huelva asked us whether there were any records of bigeye tuna (Thunnus Obesus) and albacore (Thunnus Alalunga) in the Gulf of Cádiz, in Spain, and the Algarve, in Portugal.
David Macias and Sámar Saber from the Spanish Institute of Oceanography answered his question:
Diagram of approximate species distribution
Yes, there are records of bigeye and albacore tuna in the area around the Gulf of Cádiz and the Algarve. The Spanish Institute of Oceanography has genetically identified juvenile specimens of both species. When they are young, the two are so similar that it’s easy to get them confused. There have been years when longline fishermen in Huelva occasionally caught bigeye near Cape San Vicente. In these areas, bigeye tuna are at the limit of their distribution and few specimens are found, although in recent years the Cantabrian fleet has reported a rise in catches. In the rest of the Mediterranean and the Cantabrian Sea, albacore tuna are widespread. In the Balearic Islands, one of the main tuna spawning grounds in the Mediterranean, we have never identified bigeye larvae, whereas albacore larvae are fairly common.