What scientific observations tell us about catches in the artisanal purse-seine fishery off the Canary Islands

In the Canary Islands, the small-scale fleet performs daily fishing trips, being the small pelagic species usually caught with purse-seines. In 2017, a monthly programme of scientific observations was launched to characterize the catches of the artisanal purse-seine fleet, whose discards were considered irrelevant. Here we present a summary of the species composition recorded during 61 fishing trips and the size structure of the main targeted species (i.e. Scomber colias, Trachurus spp., Sardinella spp. and Sardina pilchardus), including both the retained and discarded catches. In the period under study (2017-2021) discards reached noticeable values of around 25% of the total fish caught, attaining 40% if we look at the catches of S. colias. The main reasons observed for discarding fish are market demand and the mean size of the school caught, which generally lead to the net slipping (i.e. the process to open the purse-seine to release excess or unwanted catch into the sea), a regular practice that remains unrecorded and estimates are difficult to report.
Estudio parcialmente financiado por el Fondo Europeo Marítimo y de Pesca (FEMP) a través del Programa Nacional de Datos Básicos del sector pesquero español para la recopilación, gestión y uso de los datos del sector pesquero y el apoyo al asesoramiento científico, en relación con la Política Pesquera Común.