Catching efficiency of multifilament trammel nets with different twisted twine for shrimp fishing in Kotabaru, Indonesia

Abstract

Fishing experiments were carried out in Kotabaru of Indonesia to determine catching efficiency of double-twisted and triple-twisted multifilament trammel nets. A total of 10 nets were constructed with the same dimension and inner-outer mesh sizes (40-mm and 80-mm). Trials covered 160-net hauls/type with 1-hour submersion time. The shrimps were composed of Penaeus monodon , Penaeus merguensis , Metapenalis monoserus, Penaeus semiculatus and Parapenaeopsis sculptilis . A total of 142.8 kg shrimp comprises 84.46 kg (59.15%) for double-twisted and 58.34 kg (40.85%) for triple-twisted were collected over 16-daytrip sampling period, indicating double-twisted multifilament trammel net was 45% more efficient. The average weight of double-twisted (5.25±1.64 kg) was considerably higher than that of triple-twisted (3.65±1.41 kg) as well as total YPUE of double-twisted (1.056±0.02 kg) was considerably higher than that of triple-twisted (0.729±0.02 kg) ( P <0.05). Some recommendations for improving performances and efficiency of trammel nets are made, for example, by inserting the additional bag collector along the lower part of the nets, placing selvedge between the lead line and the net or using underwater lamps associated with the net.