Abstract
Since the 17th century, the T onnarella of C amogli, a small tuna trap, has been used to catch pelagic fish along the western coast of the P ortofino P romontory ( L igurian Sea, N orthwestern M editerranean). The availability of long‐term datasets on fish yields (1950–1974 and 1996–2011), with information related to the seawater temperatures and the North A tlantic O scillation ( NAO ), has allowed us to study the qualitative and quantitative changes in fish yields in the last decade and the possible relationships with the seasonal anomalies of temperature that have occurred in the L igurian S ea. In 1950–1974, yields remained relatively constant over time (average of 35.6 ± 8.7 t·year −1 ). From 1996 through 2011, yields were high (42.9 ± 15.9 t·year −1 ) but inconsistent with strong annual variability in catches. The primary catches are S eriola dumerili , A uxis rochei, T rachurus spp. and S arda sarda . Changes in species composition have occurred as well: S . dumerili, S ardinella sp. and B elone b elone have appeared recently. Moreover, a significant decrease in the boreal scombroid ( S comber scombrus ) and an increase of warm‐temperate carangids and other typically Southern Mediterranean species such as C oryphaena hippurus and S phyraena viridensis, appear to be linked to the warming of the surface water layer, particularly evident in the L igurian Sea, for the last 10 years. The analysis of this kind of trend may be a powerful tool for assessing structural changes of the pelagic fish community in the L igurian Sea ( N orthwestern M editerranean).