مرکز منطقه ای اطلاع رساني علوم و فناوري - Structural characteristics of towed fishing gears used in the Samsun coast (Black Sea)

Abstract :

In this study, structural characteristics of towed fishing gears (bottom and beam trawls) used on the coasts of Samsun were investigated as part of EU-FP7 BENTHIS project. Data for bottom and beam trawl (net, otter board, beam etc.) were obtained in situ investigations and survey studies with fishermen face to face. The numbers of total and active trawl vessel in this area were determined after that these vessels were classified according to size categories. Stratified subsampling for representing the main fleet is taken from that worked during 2011/12 and 2012/13 fishing season. General characteristics of the bottom trawl nets are in two configurations and cutting shape, whereas the otter boards are rectangular shaped. In these nets the number of meshes in fishing circle is changed between 450 and 975, 650 and 750 meshes are the most preferred (%38). All of the bottom trawls (40-80 m depths) are towed with a stern trawler, the engine powers of these vessels are changed between 99 and 1067 kW and 57% of these vessels are between 200 and 500 kW. Rapa whelk (Rapana venosa) fishery is also heavily done with beam trawls on the coasts of Samsun (5-30 m). Some technical differences were observed between the functional designs of the beam trawls used in different locations. While 77% of the beam trawls with engine power between 9.6 and 285 kW were used pair gears on deck, the rest was performed with a single gear. The length and weight of the beam trawls changed 2-3.2 m and 22-61 kg, respectively. As a result, a number of modifications for both fishing gears have been made for more catch so far. There is a need to reveal the changes, monitoring and known to the structural characteristics of these gears for ecosystem approach fisheries.