Spanish scientists discovered that there is a clear relationship between the spawning areas of bluefin tuna in the Mediterranean Sea and the location of the fronts separating waters of recent Atlantic origin (which go into the Strait of Gibraltar and move up to Balearic Islands) and residents waters, which can vary each year.
The research was conducted by a team of researchers from the Balearic Oceanography Centre of the Spanish Institute of Oceanography (IEO). They found that Bluefin tuna relied heavily on environmental signals, and therefore their spawning habitats can vary depending on the environment. In contrast, the spawning habitat of albacore and bullet tuna was driven mostly by geography and was less variable over contrasting environmental conditions. These regional adaptations for spawning habitats among the 3 tuna species may play a critical role in offspring survival and species interactions, and should be taken into account when establishing conservation practices.
Both the bluefin and albacore tuna primarily spawn in deep water. Bluefin tuna spawns primarily between mid-June and July, and Albacore in late July and early August.