Comparative Analysis of Three Types of Fishing Gear Marking for Anchored Fish Aggregating Devices in Purse Seine Fishery in Thai Waters

摘要

Anchored fish aggregating devices(AFADs)have been widely used for fishing in Thai waters.However,abandoned,lost,and discarded fishing gears(ALDFGs),including lost AFADs,may cause environmental impacts.Fishing gear marking(FGM)is considered as a tool to help identification of ALDFGs.The main objective of this study is to compare the durability represented by the percentage of remaining condition(R-value)of three material types of FGM applied for AFADs,i.e.,stainless steel(SS),colored acrylic(CA),and polypropylene(PP).This study was carried out using 50 AFADs deployed in the Gulf of Thailand(GOT)and the Andaman Sea(ANS)between July and October 2020 in cooperation with 10 fishers.The AFADs were deployed in similar habitat(bottom depth and type)between the GOT and the ANS.The three material types of FGM were assumed to be sufficiently durable to last for the lifespan of the AFADs in both the GOT and the ANS(within 2 months and 3.5 months,respectively)though some FGMs in the ANS were detached from cable ties or broken before AFADs were lost.The loss of AFADs and FGMs was mainly caused by adverse weather condition(rough sea).Only data from the ANS was included in comparative analysis due to the insufficient variance data obtained from the GOT.The analysis revealed that SS had the higher durability than CA and PP when the AFADs lasted for less than 3.5 months.As a result of our study,some recommendations were made.For example,the cable ties can be replaced by ropes or threads to improve the installation method.This study serves as a basis to develop FGM and to support responsible fisheries.Beneficiaries of the study include fisheries policy makers,managers,and fishers.