The present short communication takes into consideration the status of demersal resources harvested by trawling Italian fleet, in the Central-Western seabed of the Northern Adriatic Sea. The evolution of landings and effort in a 45 years period from 1969 to 2013 (Relaz. Bombace) evidenced a period of good productivity, lasted 16 years, characterized by increasing fishing effort and decreasing CPUE, followed by a decrease from more than 100,000 t / year (years 1982-1984) to around 36,000 t / year (years 2000-2013). It is also noted that not only in GSA 17, but also in the southern Adriatic and in the other Italian sub-basins, demersal resources are overexploited (Bombace and Grati, 2007). Only in the latter period (2004-2013) the decline of catches showed a more moderate trend, while in the last year (2013), the fishing effort reaches its minimum (207,800 KW) , slightly more than the beginning (1969) of this long cycle in which the fishing effort was of 196,225 KW. The CPUE reassemble, reaching the level of 191 kg / kW / year 2013, compared to 113.7 kg / kW / year 2000; minimum for all Adriatic). To understand on which stocks depend a possible turnaround, to be verified in the coming years, we focused on this last period (2004-2012) for which there are regional data. Finally, comparison and integration of statistical data relating to regional landing with the data and observations of experimental samples in the field, allows for some stocks, such as sole and hake, an ecological reading of environmental statistics of capture and catch / effort, which concerns the areal distribution of the two stocks and also the peculiarity of distribution related to ecologically disturbed areas. Moreover, the different distribution of size classes in the two biota, eastern and western part of Northern Adriatic Sea, reveals a biological and ecological role, but complementary in the two environments (ADRIAMED 2013 Scarcella et al., 2014 ). A first economical observation for the period 2004-2012 is the following: in GSA 17 (Geographical Sub Area by GFCM) reduction of demersal catches carry on, except in the last year. The loss, (the difference between the years 2004 and 2012) was 11,009 tons. (42%) and 70.495 million of Euro (35.5%). As regards the Adriatic, the loss of demersal catches was 26,041 tons (44.9). In the last year we are observed a slight recovery. It is due to the hake, sole and caramote prawn. Regarding the Adriatic resources management, the existence of two biomes, Western and Eastern, different for geomorphological, ecological and biological characteristic, while complementary, postulates two management guidelines: in the East, to defend the adult stock to avoid in problems of overfishing recruits, in the West, protecting the immature juvenile, to avoid problems of growth overfishing.
Andamento e stato delle risorse demersali in Adriatico nel periodo 2004-2012 e considerazioni alieutiche, economiche ed ecologiche.
L Bolognini;G Bombace;F Grati;G Scarcella
2017
Abstract
The present short communication takes into consideration the status of demersal resources harvested by trawling Italian fleet, in the Central-Western seabed of the Northern Adriatic Sea. The evolution of landings and effort in a 45 years period from 1969 to 2013 (Relaz. Bombace) evidenced a period of good productivity, lasted 16 years, characterized by increasing fishing effort and decreasing CPUE, followed by a decrease from more than 100,000 t / year (years 1982-1984) to around 36,000 t / year (years 2000-2013). It is also noted that not only in GSA 17, but also in the southern Adriatic and in the other Italian sub-basins, demersal resources are overexploited (Bombace and Grati, 2007). Only in the latter period (2004-2013) the decline of catches showed a more moderate trend, while in the last year (2013), the fishing effort reaches its minimum (207,800 KW) , slightly more than the beginning (1969) of this long cycle in which the fishing effort was of 196,225 KW. The CPUE reassemble, reaching the level of 191 kg / kW / year 2013, compared to 113.7 kg / kW / year 2000; minimum for all Adriatic). To understand on which stocks depend a possible turnaround, to be verified in the coming years, we focused on this last period (2004-2012) for which there are regional data. Finally, comparison and integration of statistical data relating to regional landing with the data and observations of experimental samples in the field, allows for some stocks, such as sole and hake, an ecological reading of environmental statistics of capture and catch / effort, which concerns the areal distribution of the two stocks and also the peculiarity of distribution related to ecologically disturbed areas. Moreover, the different distribution of size classes in the two biota, eastern and western part of Northern Adriatic Sea, reveals a biological and ecological role, but complementary in the two environments (ADRIAMED 2013 Scarcella et al., 2014 ). A first economical observation for the period 2004-2012 is the following: in GSA 17 (Geographical Sub Area by GFCM) reduction of demersal catches carry on, except in the last year. The loss, (the difference between the years 2004 and 2012) was 11,009 tons. (42%) and 70.495 million of Euro (35.5%). As regards the Adriatic, the loss of demersal catches was 26,041 tons (44.9). In the last year we are observed a slight recovery. It is due to the hake, sole and caramote prawn. Regarding the Adriatic resources management, the existence of two biomes, Western and Eastern, different for geomorphological, ecological and biological characteristic, while complementary, postulates two management guidelines: in the East, to defend the adult stock to avoid in problems of overfishing recruits, in the West, protecting the immature juvenile, to avoid problems of growth overfishing.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
