NET MOUTH INCLINATION KEEPING TYPE TRAWL NET FISHERY SYSTEM
Provided is a net mouth inclination type trawl net fishery system for controlling a posture autonomously. The trawl net fishery system comprises a trawl net including a body portion of a quadrangular pyramid shape formed of an upper net, a lower net and a pair of side nets, and a cot end portion connected to the leading end of the quadrangular pyramid shape. In the trawl net, the side net of the body portion has a longer side and a shorter side as its upper and lower sides, and the sides forming the net mouth edges such an inclination angle (?) of the side net front edge with respect to the bottom side of the a isosceles trapezoid having a shorter leg as the shorter side as satisfies the relation of the following Formula (1), so that the front edge of the net mouth is enabled to keep an inclination angle (ss) autonomously by the resistance and lift of a water flow with respect to the net: (y1CD?1 - x1CL?1)S1 + (y2CD?2 + x2CL?2)S2 + 2ySCD?SSS + 2awfsinss/(?aV<2>) = 0 - - - (1).