Relationship on the Characteristics of Trawl Net, Otter Board, and Trawler of Thailand

Abstract

The study on the Relationship of the Characteristics of Trawl Net, Otter Board, and Trawler of Thailand is carried out by using the data of trawl net, accessories and trawlers from the trawl fishing gear and trawler survey along the coast of the Gulf of Thailand, in the year 2015. Forty-six (46) bottom trawl nets of thirty-seven (37) otter board trawlers were surveyed and collected technical data, i.e. length overall (m), trawler size (gross tonnage: GT), engine power (kW), otter board area (m2), otter board height (cm) and head rope length (m). Result of the study reveals that trawler size, engine power, the height of otter board, area of otter board, head rope, and ground rope, shows the correlation among them, between 0.73 - 0.99 at confident level 95% The very high correlation, 0.986, is found in the comparison between the height of otter board and length of otter board. The lowest correlation, 0.727, was found in the comparison between gross tonnage and head rope. The study on the influence of independent variable i.e. length overall (m), trawler size (GT), engine power (kW), otter board area (m2), otter board height (m), and head rope length (m) to dependent variable shown by R-square value at confidence level 95% Range of R-square value between 21% - 91%. The highest R-square value, 90.94 was found in the comparison between the area of otter board and length of otter board. The lowest R-square value, 21.88 was found in the comparison between engine power and head rope length. Fisheries manager can apply the study result to control the efficiency of the trawl net. Management measures on trawl gears and trawlers can apply through fishing gear inspection on the trawl parts which can be selected from the study result, such as the area of otter board, engine power, ground rope, etc. According to that trawl net and trawler collected in this survey was less in number compared with the total trawl net of Thailand, further data collection should be continue undertaken to generate a more accurate result to serve better management.