Deepening our pelagic vision of the small pelagic fish in the Canary Islands (NW Africa, Spain)

Abstract

The small pelagic fish (SPF, i.e. Scomber colias, Trachurus spp, Sardina pilchardus and Sardinella spp) in the Canary Islands archipelago (Spain) are mainly targeted by artisanal purse-seiners, whose monitoring is included in the EU Data Collection Framework. The waters in the archipelago (located in the coastal transition zone of the Canary Current Eastern Boundary Upwelling System) are monitored since the late nineties by a hydrographic section (RAPROCAN) designed to study the temporal variability of the eastern subtropical gyre. Official fish landings, reported by the Government since 2007, are annually analyzed to assess the stock status of the SPF in the Fishery Committee for the Eastern Central Atlantic (CECAF) context. In this study we analyze the relationship between the SPF abundance assumed from official landings and the oceanographic parameters. Using the sea temperature in the 200-800 m layer, we obtained a statistically significant correlation with the SPF landings (ρ-Pearson=0.454, p<0.03) when we considered one-year time-lag. This layer is less affected by atmosphere variations and probably influence on the success of the SPF spawning and recruitment processes. In fact, recruitment to the fishery (i.e. individuals attain legal catchable sizes) approximately occurs for one-year-old individuals, and explaining the one-year time-lag. Keeping the monitoring systems is crucial to understand, foreseen and anticipate potential variations in the fishery resources and to aim the sustainable exploitation of the SPF populations, even more challenging in the current Climate Change scenario.