The Effect Of Hook Size On Size Selectivity In Bardawil Lagoon Artisanal Longline Fishery, Eastern Mediterranean, Egypt

F. Mehanna, Sahar; D. Hassanen, Gaber; S. Ahmed, Mohamed; A. Mohamed, Ola

doi:10.21608/ejabf.2021.145706

The Effect Of Hook Size On Size Selectivity In Bardawil Lagoon Artisanal Longline Fishery, Eastern Mediterranean, Egypt

Document Type : Original Article

Authors

10.21608/ejabf.2021.145706

Abstract

The size selectivity and fish species of longline fishery using small hooks were studied in Bardawil lagoon using hooks of different sizes (numbers 10, 12, and current 13) baited with small shrimp. Hook numbers 10 and 12 are 67 and 32% larger respectively than number 13 hooks in terms of maximum width and 24 and 15% larger respectively in terms of maximum length. A total of 12600 hooks were ﬁshed in 18 sets targeted European eel that fished during three months October, November, and December during 2019 and repeated in 2020. As a bycatch, seabass, sea bream, sand flathead fish, and grouper are dominated in the catch along with undersized eel. The distribution of catch size according to the different hook sizes was, in general, highly overlapped for all caught species and the hook size had clear eﬀect on maximum and minimum length at capture. All experimental hooks fished a wide range of lengths per species, but the catch rate (number of ﬁsh per 100 hooks) was signiﬁcantly lower for the largest hook except for seabass. The capture of illegally sized or immature ﬁsh was high in all hooks but much higher in the smallest hook except for seabass. Clear increases in average size with hook size were evident for target and bycatch species. The results of selectivity experiments in terms of the 50% retention length (L_c, the fish length corresponding to 50% chance of capture) were presented reflecting the increase of Lc with the increase of hook size.

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