Orijinal Boyuttaki Geleneksel ve Kesimli Dip Trol Ağlarının Sualtı Gözlemleri ve Performans Ölçümleri.
Makaleler > Tam Makale · 2015
Yazarlar: Zafer TOSUNOĞLU, Muharrem Hakan KAYKAÇ, Faik Ozan DÜZBASTILAR
DergiPark (Istanbul University), Uluslararası, 2015
Özet
Underwater observations and performance measurements of full-scale conventional and tailored demersal trawl nets.This research comprises full-scale net performance test of conventional and tailored demersal trawl nets.Tests were carried out with fisheries research vessel Egesüf (500 HP main engine) at "Kumburnu Site" between 15 September and 15 December in 1997.Towing speed was about 2.0 mile hour -1 , and towing duration was 30 minutes.Direct observation and performance records of the fishing gears in operation were obtained by three scuba divers.The features observed in both two gears during the tows are the curve of the footrope is much wider than the curve of headline, the wing forms a triangular wall and the height and cross section of this wall increase from the danleno towards the junction with the body, and the cross section of the nets' body is ellipse-like, becoming more and more circular in form towards the codend.The differences are different danleno gear gives higher opening height for the tailored net during the tow and mesh cutting and forming techniques affect mesh opening.It is thought that the material used in making net also plays an important role in these differences.The constructional differences in trawl nets are also seen in performance results of the gear.In the tests, which were carried out under similar towing conditions, vertical mouth openings were found 110 and 230 cm for conventional and tailored nets, respectively.A similar difference was also found in horizontal wing spread.These values are 610 cm at conventional net, and 960 cm at tailored trawl.Consequently, It was found that performance values of the tailored bottom trawl net are higher than conventional trawl net under the same towing condition.