Portuguese Commercial Fisheries of Swordfish, Xiphias gladius
Swordfish (Xiphias gladius) plays an important role in Portuguese fisheries. Portuguese commercial swordfish landings were analyzed from 1986 to 2012. Commercial landings of five incidental catches of pelagic sharks—bigeye thresher shark (Alopias superciliosus), thresher shark (Alopias vulpinus), shortfin mako shark (Isurus oxyrinchus), blue shark (Prionace glauca), and smooth hammerhead shark (Sphyrna zygaena)—were also evaluated for the same period. A total of 653 landings of swordfish (12,625 t) were observed in 62 ports. Annual landings for the fishery generally decreased over time, with a corresponding increase in price per kilogram. The most fished shark was blue shark, with 12,715 t in 48 ports. It was followed by shortfin mako, thresher, smooth hammerhead, and bigeye thresher (with 5113 t, 672 t, 19 t, and 0.45 t, respectively). Lowest landings of swordfish were observed in the first semester of each year, while catch levels of blue sharks were high during the same period. Shortfin mako catches did not raise until 2005. The remaining species studied always displayed lower landings, suggesting that most of them are bycaught.