Performance and Feasibility Study of a Novel Automated Catch-Hauling Device Using a Flexible Hose Net Structure in Set-Net

Qiao Li,Yoichi Mizukami,Shuchuang Dong,Jialin Han,Yue Li,Daisuke Kitazawa,Takero Yoshida

doi:10.3390/jmse9091015

Abstract

The labor-intensive catch-hauling method in set-net fisheries faces problems of lower productivity, lower efficiency, and higher operational risk due to aging problem and labor insufficiency. To solve such problems, a novel catch-hauling device using the flexible fire hose and net (hose net), which is placed in the box chamber, was proposed in this study. The hoses were inflated with air injected into one edge of the hose net, and the buoyancy force increased: the net gradually floated up, cornering the fish in the opposite edge. To corner and harvest the fish efficiently and safely, the changing formation and motion parameters of the hose net are significant. A series of floating up, sinking experiments, and catch-hauling tests were conducted to evaluate the performance of this device. The results showed that the hose net could gradually float in an ideal form and sink smoothly through natural exhaust and stretched on the bottom of the water tank. The time spent and average speeds in floating and sinking processes varied with air pressure and airflow rate, allowing the hose net motion to be controlled in practice by adjusting the airflow. Through the catch-hauling test using live fish, most of the fish were directed into the fish bag. Two main capture failure phenomena were also observed. Overall, this newly developed automated catch-hauling device is expected to be successful for use in modern fisheries.

Highlights

The set-net is a type of stationary pound net [1] that is frequently used in the coastal areas of Japan, South Korea, and Canada to passively capture fish [2,3,4]
In some set-net, there is a fish bag net attached to the box chamber net
A unique automated catch-hauling apparatus based on a flexible fire hose with a cover net was developed to deal with aging populations

Summary

Introduction

The set-net is a type of stationary pound net [1] that is frequently used in the coastal areas of Japan, South Korea, and Canada to passively capture fish [2,3,4]. Compared with the traditional trawl, set-net fishing is an efficient fishing method without excessive fuel consumption [4,5]. In some set-net, there is a fish bag net attached to the box chamber net. The leading net directs the fish to swim into the set-net and is collected in the box chamber net (Figure 1). TTootthheebbeessttooffoouurr kknnoowwleleddggee, ,oonnlylyaaffeewwssttuuddieiesshhaavveerreeppoorrtteeddoonnaauuttoommaatteeddhhaauulilninggddeevviciceess..FFoorreexxaammppllee,, aairirbbaaggssppllaacceedd iinnssiiddee tthhee bbooxx cchhaammbbeerr nneett wweerree ffiirrsstt tteesstteeddiinntthhee11992200ss[1[133].].FuFkuakhaohroireit eatla. TThheerreeffoorree,, wwee iimmpprroovveedd tthhee ccoonnvveenniieenntt oonn--ssiittee ooppeerraattiioonn aanndd ccaattcchh--hhaarrvveesstt ppeerrffoorr--. .TThheehhoosseenneettbbuuooyyaannccyy aanndd wweeiigghhtt sshhoouulldd bbee aaddjjuusstteedd ssuucchh tthhaatt iittmmaayyflflooaattuupptthheeccoovveerrnneettttiinnggaannddssininkkwwitithh iittss oowwnn wweeiigghhtt. Eng. 2021, 9, 1015 ability to float up and sink. When using this new approach to catch live fish in a tiny w4aotfe1r7 tank, we examined fish school movement

Material and Methods

Experimental Measurements and Analysis

Live Fish

Experimental Conditions

Findings

Conclusions