Color effect of the environment-friendly sinker for octopus drift-line

Abstract

The choice behavior of the octopus in response to the environment-friendly colored sinker for octopus drift-line and the sinkers fishing effect were studied under experimental conditions in the water tank and thefield. The colors of the sinkers used for the experiment are white, black, yellow and green. Artificial baitsare attached to the sinkers in order to attract the octopuses in the experiment. In the water tank experiment,two sinkers of two different colors are placed in a compartmentalized corner of the rectangular tank, and aCCD camera records the choice behaviors of the octopuses to the colored sinkers. In the field experiment,the catch investigation of octopus for each colored sinker was conducted 14 times in total by using 2(A, B)commercial fishing boats at the coast of Gangneung within 30m of depth in 2006. The number of coloredsinkers per operation was a total of 24-40 pieces with the same number of sinkers individually for fourcolors. As a result, it was found that the octopus selected white the most followed by black and yellow intheir choice of colored sinkers in the water tank experiment, and green was the lowest in their choice. Evenin the field experiment, the sinkers of white and black showed a higher catch of octopus than the sinkers ofyellow and green. Key words : Octopus Drift-line, Environment-friendly Sinker, Color effect