Climate Change Drives Sardine Migration Along Northwest African Coast, Study Finds

Small pelagic fish, especially sardines, are migrating along the coasts of North-West Africa, reveals a recent study published in the journal Scientific Reports. The work carried out by scientists from various institutions in Senegal, France, Norway, Morocco, Mauritania and Gambia analyzed data from 2,363 trawl samples and 170,000 km of acoustic surveys at sea conducted between 1995 and 2015.

The results reveal that the southern part of the Canary Current Large Marine Ecosystem (CCLME), which extends from Morocco to Senegal, has experienced significant warming over the past 34 years, and that this warming trend has been accompanied by changes in wind speed and upwelling intensity, particularly in areas where coastal upwelling was already strongest. The researchers claim to have observed a significant northward shift in the northern limit of Sardinella aurita, which has moved northward at a rate of 181 km per decade since 1995. Similarly, the abundance of sardines has increased in the subtropical regions and decreased in the intertropical region, the study reveals.

The average sea surface temperature (SST) and a decrease in marine productivity in the southern regions of the CCLME are at the origin of this long-term trend change, the researchers estimate, noting that the northward shift of sardine populations has significant implications for Morocco, which has seen an increase in sardine catches in recent years. The exceptional presence of sardines as far north as Casablanca in 2015 is likely linked to the northward shift in their distribution observed in this study.

Affected by climate change, including drought, desertification and sea level rise, Morocco, like the rest of North-West Africa, sharing the same fish stocks, should benefit from this migration of sardines, the researchers also estimate. They recommend that they adopt a common regional policy in favor of food security and food sovereignty.