The effect of the entrance size on the catch of trap for conger eel

Recently, Fishermen have required to expand the circumference of trap entrance for conger eel because it wasdifficult to take the catch out as well as to put the baits into. A series of fishing experiments was carried out incoastal areas of Tongyoung, Korea in 2008 and 2009 using the traps to describe the effect of the entrance size onthe catch. The experimental traps (five types) were used in filed experiments with four types circumference sizetraps (140, 180, 220 and 260mm) with mesh size 22mm and another type was used the same one usually using infiled with mesh size 35mm (750mm circumference). The experiment results were, the conger eels of total length35mm more or so were caught 85, 93, 142 and 176 individual by the experiment traps with mesh size 22mm asincrease circumference size from 140mm to 260mm, respectively. And the small conger eels of the total lengthbelow 35mm to be prohibited to catch by law were caught 145, 160, 288 and 304 individual according toincrease the circumference size of trap, respectively. In addition, in case of the trap with mesh size 22mm,bycatches were 230260 individuals and much more than bycatches of the trap with mesh size 35mm. Inconclusion, when we expand the circumference size of trap according to fishermens requirement, we shouldreview not only economic of fishery but also increasement the bycatch of non-target fishes and small size fishes.Keywords: Bycatch, Conger eel, Entrance size, Selectivity, Trap