Tuna are globally distributed species of major commercial importance and some tuna species are a major source of protein in many countries. Tuna are characterized by dynamic distribution patterns that respond to climate variability and long-term change.
This study investigated the effect of environmental conditions on the world-wide distribution and relative abundance of six tuna species between 1958 and 2004 and estimated the expected end-of-the-century changes base on a high-greenhouse gas concentration scenario (RCP8.5).
The results show that over the historical period, suitable habitats shifted poleward for 20 out of 22 tuna stocks. On average, tuna habitat distribution limits have shifted poleward 6.5 km per decade in the northern hemisphere and 5.5 km per decade in the southern hemisphere. The authors state that larger tuna distribution shifts and changes in abundance are expected in the future, especially by the end-of-the-century.
It is concluded that the results of the study provide global information on the potential effects of climate change in tuna populations and can assist countries seeking to minimize these effects via adaptive management.
Erauskin-Extramiana et al. (2019) Large-scale distribution of tuna species in a warming ocean. Global Change Biology 25:2043-2060.