Elasmobranch landings in the Portuguese commercial fishery from 1986 to 2009

Portuguese commercial Elasmobranch landings were analysed for the period 1986 2009 and revealed that some species may be in danger of overfishing. Landings totalled 122,515 mt, with an average of 5,105 mt landed yearly, with captured sharks, skates and rays representing 8 orders, 14 families and 44 species. Annual landings for the fishery generally decreased over time, with a corresponding increase in price per kilogram. The most landed group, skates (Raja sp.), accounted for 33% of the landings, or 40,344 mt. They were followed by lesser spotted catsharks (Scyliorhinus sp.), Portuguese dogfish (Centroscymnus coelolepis), leafscale gulper sharks (Centrophorus squamosus), blue sharks (Prionace glauca) and gulper sharks (Centrophorus granulosus) (accounting for 12%, 11%, 10%, 9% and 8% of the landings, respectively). In the absence of CPUE data, comparative trends of landings and price over time were used as an indicator of the status of specific Elasmobranch species. Centrophorus granulosus, smoothounds (Mustelus sp.), torpedo rays (Torpedo sp.), requiem sharks (Carcharhinus sp.) and angel sharks (Squatina sp.) displayed indications of possible over-exploitation, with significantly decreasing landings and increasing prices over time, and merit the focus of future research. The pattern shown by fishing effort over time (i.e. number of fishing vessels over time) displayed a marked decrease, although this was substantially less than the decrease shown by landings of the species mentioned earlier. It is therefore unlikely that such a decrease in landings is justified solely by a decrease in number of fishing vessels. Similarly, the increase in price shown for all species was largely superior to the increase in inflation, which would suggest that the increase in inflation alone would not account for the increase in price. All results and data corroborate the notion that some species are, in fact, over-exploited and in need of immediate management and conservation measurements. These findings were substantiated by min/max auto-correlation factor analysis (MAFA), which shows that the most important trend is that of a decrease in landings of those species where overfishing in indicated.