Merluccius merluccius is a demersal fish species that has been found in depths ranging from 30 to 1,075 m. It is heavily exploited in the northern Atlantic Ocean and is a target species in most Mediterranean fisheries for its high economic value. Although on a global level, the IUCN status is “least concern”, in the Mediterranean, it is considered an overfished species. Among all catching methods used to catch M. merluccius, set nets – more specifically gill nets – are the most frequently used in small-scale European fisheries.
The principle of gill nets is to have IND entangled for hours resulting in stress and injuries up to mortality, so there is no way to avoid this decrease in welfare except for shorter soaking times. This may be a solution to IND being scavenged by predators, too. Since catching of M. merluccius takes place in great depths, there is the risk of barotrauma and osmoregulatory distress. After hauling the net, IND are subjected to exposure to air, contact with the gear, experiencing their own weight, and handling (including dropping and throwing) through emersion, release from the gear, and sorting. For storing, they might already be dead which prevents prolonged suffering by asphyxia or hypothermia, but a stunning step is missing. Accidentally caught M. merluccius experience the same treatment until they are discarded after sorting. Avoiding bycatch may be managed through mesh size, although undersized IND may still be entangled by their teeth. Closure of fishing areas or seasons might be more successful.
