Standardization of cod-end mesh size in shrimp trawlers with less than 250 Hp power engine (Case study: Bushehr coastal waters)

Abstract

The non-standard size of the trawl fountain, especially in the bag section, increases the amount of incidental catch and non-target species caught. With the aim of standardizing the trawl springs in small floating vessels, trawl tours with 36, 40, and 44 mm fountains were used in Bushehr waters in 1396. The sampling site and sampling operations were carried out under similar conditions. And was carried out in three depth classes less than 10 meters, 10-20 meters, and 20-30 meters. At the end of the 9 trapping sequences, the species of whitefish (Metapenaeus affinis), green shrimp (Penaeus semisulcatus), shrimp (Parapenaeopsis stylifera), shrimp, or violin (Metapenaeopsis stridulans) and trachypenaeus granulosus Combined shrimp fishing. The tiger shrimp was the highest shrimp catch with 92.74%. The results also showed that depth and mean length of shrimp are significant. Also, in studying three sizes of fountains, the highest frequency of tiger shrimp was 7-10 cm. In the survey of catches, the highest catch of tiger shrimp in the 36mm fountain was found, with the highest amount of coding done on the tour. In the 36 mm range, the L50 was 5.92523 cm in the 36 mm trowel, the L50 was 6.58057 cm long and the length of 44 mm was LM50 7.233867 cm.

Keywords

• mesh sprinkler
• selectivity
• trawl
• shrimp
• bushehr