Catalan Sea (Southern) - Exploitation

The southern Catalan Sea study area includes 7 fishing harbours from Tarragona to Les Cases d’Alcanar (Figure 1). Trawling, purse seine, and long line and troll bait are the most important fisheries in terms of catches, while an important artisanal fleet is still present (with 195 boats in 2006).
Small pelagic fish (overcoat sardine and anchovy) constitute the principal component of the catches in terms of biomass and are mainly caught in purse seines and by bottom trawlers. The demersal fishery comprises mainly juveniles of several target species, e.g. hake, red mullet (Mullus barbatus), anglerfish (Lophius spp.) and blue whiting (Micromesistius poutassou), caught principally by the trawling fleet. Large demersal fish (e.g. adult hake) and large pelagic fish (e.g. Atlantic bonito Sarda sarda, bluefin tuna and swordfish Xiphias gladius) are caught by long line and troll bait fleets.
Historical official landings from the Catalan Sea increased dramatically from the beginning of the 19th century to the 1960s and from then to 1990s, mainly due to the expansion of the fishery and public incentives to the fishing sector. Marked fluctuations in landings occurred from the 1970s until they underwent a progressive decrease from 1994. More recent data from the southern Catalan Sea showed similar patterns, while nominal fishing effort progressively increased to mid 1990s (Bas et al.. 2003). From 1994 to 2003, total official landings have declined by 55% and in 2003, were similar to those attained in the late 1970s. This reduction was mainly due to the pelagic fraction, which also exhibited marked inter-annual fluctuations and underwent a reduction of 70.2% in the case of anchovy official landings and a reduction of 70% in the case of sardine landings. Demersal landings have been maintained at similar levels since 1983, with a reduction of 18% in landings, and underwent smaller fluctuations over the period of decline in the pelagic fraction. Discards, by-catch and illegal, unregulated or unreported (IUU) landings are important in the southern Catalan Sea (Sánchez et al.. 2004, Tudela 2004, Coll et al.. 2006b). Average IUU estimates amounted to 25% of the official landings for 2002, while in some cases and for some species IUU comprised 50 to 100% of the official data, or even more (especially for commercially important species).
The scientific general assessment suggests that several demersal stocks are now fully exploited or overexploited, while some pelagic stocks also show signs of overexploitation. There is increasing concern about recruitment overfishing of North-western Mediterranean anchovy stocks (Palomera et al.. 2007), while growth overfishing affects some demersal resources because for many species the sizes at first catch are very similar to those at which the fish recruit (Sardà 1998, Lloret and Llenonart 2002). Moreover, the introduction of new fishing procedures such as modern long lines, e.g., for adult hake, has eliminated the spawning refuge of some species and has lead to increasing concern about recruitment overfishing of some demersal stocks (Aldebert and Recasens 1996).
The southern Catalan Sea has been highly impacted by fishing activity since the 1970s (Coll et al. 2006b, 2007a, 2008, 209) and nowadays there are high probabilities of ecosystem overfishing (Tudela et al. 2005, Libralato et al. 2008, Coll et al. 2009). In fact, evidence of fishing activity going back to ancient times can be found all around the Mediterranean Sea (e.g. Cutting 1956, Florido 2004). Fishing technology, overcapitalization and the increasing market demand is placing intensive pressure on exploited resources of the Mediterranean (Margalef 1985, Bas et al. 1985, Farrugio et al. 1993, Papaconstantinou and Farrugio 2000, Bas et al. 2003). Recent analysis of biodiversity patterns and threats in the Mediterranean Sea identified the coastal areas of the Western Mediterranean Sea as areas hosting a high degree of marine biodiversity but highly threatened by numerous human activities (Coll et al. 2010, Coll et al. 2011). Moreover, marine protected areas in the region hardly cover any of this biodiversity (Mouillot et al. 2011).