Changes in life-history traits in relation to climate change: bluefish (Pomatomus saltatrix) in the northwestern Mediterranean

Abstract

Sabatés, A., Martín, P., and Raya, V. 2012. Changes in life-history traits in relation to climate change: bluefish (Pomatomus saltatrix) in the northwestern Mediterranean. – ICES Journal of Marine Science, 69: 1000–1009. This study shows the strong relationship between the increasing surface temperature in the NW Mediterranean and the expansion northwards of the bluefish distribution range with the species reproducing in the new distribution areas. Two shifts in temperature were detected: the first one in the early 1980s and the second around 1997. This last shift, explained by warmer springs (April–June), when the species migrates for spawning, led to the observed changes in bluefish. In the western Mediterranean basin, a significant increase in bluefish landings was observed by the mid nineties, whereas in the Catalan coast, the northern edge of the species distribution, a northward expansion was observed from 2000. At present, spawning takes place all along the Catalan coast (June to September), including the new distribution areas, being 21°C the threshold for the presence of larvae in the plankton. This temperature was not attained in June two decades ago. The highest concentrations of larvae were located near the mouth of the Ebro River and their distribution to the north did not extend beyond the thermal front. Bluefish has taken the advantage of the changing environmental conditions and is established in new northernmost distribution areas.

How a multidisciplinary approach involving ethnoecology, biology and fisheries can help explain the spatio‐temporal changes in marine fish abundance resulting from climate change

“…The success of each phase and the timing of the change to the next phase will depend on environmental and biotic factors, including the ability of the species to tolerate environmental changes through phenotypic plasticity and their particular life-history features (Rosecchi et al, 2001). In this sense, our study indicates that some warm-water species including Trachinotus ovatus (Assem et al, 2005), Pomadasys incisus (Fehri-Bedoui & Gharbi, 2008), Pomatomus saltatrix (Sabatés et al, 2012), Sardinella aurita (Sabatés et al, 2006) and seem to have extended their range distribution from the south to the north of the western Mediterranean in recent decades because they were found earlier (in the 19th century and first half of the 20th century) in the relatively warm waters of the Balearic Sea and southern Catalan Sea than they were in the relatively cold waters of the northern Catalan Sea, Gulf of Lion and the Ligurian Sea (Appendix S2). Furthermore, three warmwater species (Coryphaena hippurus, Euthynnus alletteratus and Mycteroperca rubra) were caught only occasionally along the northern Catalan coast during the 20th century, but were already common during the same period in the southern Catalan Sea and/or Balearic Sea (Appendix S2).…”

“…The success of each phase and the timing of the change to the next phase will depend on environmental and biotic factors, including the ability of the species to tolerate environmental changes through phenotypic plasticity and their particular life‐history features (Rosecchi et al ., ). In this sense, our study indicates that some warm‐water species including Trachinotus ovatus (Assem et al ., ), Pomadasys incisus (Fehri‐Bedoui & Gharbi, ), Pomatomus saltatrix (Sabatés et al ., ), Sardinella aurita (Sabatés et al ., ) and Coryphaena hippurus (Massutí & Morales‐Nin, ) have a narrower spawning season in the northern Catalan Sea (centring on the warmest months of the year) than they have in warmer areas of the Mediterranean such as African waters, the eastern Mediterranean and the Balearic Islands.…”

“…Overall, our results suggest that sea warming (0.032 °C year –1 for the upper 85 m of the water column on the northern Catalan shelf from 1974 to 2005; Vargas‐Yáñez et al ., ) is partly responsible for the observed changes in the spatio‐temporal abundance of warm‐water species. Other studies carried out in the Mediterranean support the theory that sea warming may be responsible for the northward spread and increasing abundance of thermophilic species such as Pomatomus saltatrix (Sabatés et al ., ), Sardinella aurita (Sabatés et al ., ), Lampris guttatus (Francour et al ., ) or Sphyraena viridensis (Villegas‐Hernández et al ., ). Nevertheless, the responsiveness of species to climate change involves interactions with various biotic and abiotic factors (Bates et al ., ) and therefore other issues, such as the establishment of marine reserves and the consequent reduction or prohibition of fishing in such areas, may have encouraged an increase in the populations of thermophilic fish species such as Diplodus cervinus cervinus and Epinephelus spp.…”

Oceanographic factors related to Eastern Little Tuna (Euthynnus affinis) catches in the west Java Sea

“…The GAM has been utilized in the previous fishery studies related to the oceanographic factors [7,8]. The advantages in using GAM are its simplicity beside the predictor variables having non-linear effects upon the response variable.…”

Climate-driven changes in life-history traits of the bastard grunt (Pomadasys incisus) in the north-western Mediterranean

“…Sea warming is allowing northward expansion of thermophilic species in the Mediterranean (Francour et al, 1994;Molinero et al, 2005;Perry et al, 2005;Sabatés et al, 2006Sabatés et al, , 2012Lloret et al, 2014). It has been observed, in this context, that invading species may display deviant life-history traits showing, for example, great plasticity in growth and fecundity -as compared to well-established conspecific populations in other areaswhich in periods of rapid population growth may favour the processes of expansion and establishment of these invading species in new habitats (Rosecchi et al, 2001;Bøhn et al, 2004;Ribeiro & Collares-Pereira, 2010).…”