Longline hook selectivity for red tilefish Branchiostegus japonicus in the East China Sea

• Published in: Fisheries science Vol. 75; no. 4; pp. 863 - 874
• Main Authors: Yamashita, H.(Marine Fisheries Research and Development Center, Yokohama (Japan)), Shiode, D, Tokai, T
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.07.2009; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; BODY MEASUREMENTS; BRANCHIOSTEGUS JAPONICUS; Conservation; EAST CHINA SEA; ENGIN DE PECHE; EQUIPO DE PESCA; EXPERIMENTACION; EXPERIMENTATION; EXPLORATORY FISHING; Fish; Fish & Wildlife Biology & Management; Fisheries; Fisheries management; Fishery sciences; FISHING GEAR; Food Science; Freshwater & Marine Ecology; GESTION DES RESSOURCES; Hominids; Hook; Life Sciences; Longline; LONGLINE FISHING; MAR DE CHINA ORIENTAL; MEDICION DEL CUERPO; MENSURATION CORPORELLE; MER DE CHINE ORIENTALE; Oceans; ORDENACION DE RECURSOS; Original Article; PECHE A LA PALANGRE; PECHE EXPLORATOIRE; PESCA CON PALANGRE; PESCA DE EXPLORACION; Red tilefish; Resource conservation; RESOURCE MANAGEMENT; Retention; SELECT method; Selectivity; East China Sea; INW, Donghai Sea; INW, Japan; Longline; Hook; Selectivity; SELECT method; Red tilefish
• DOI: 10.1007/s12562-009-0115-z
• ISSN: 0919-9268

The catch of red tilefish by the Japanese longline fishery in the East China Sea has steeply declined during the last two decades, and resource management is clearly required. This study presents the size selectivity of hooks for red tilefish as a method to control first capture size, based on the results of longline fishing experiments using 'Tainawa-bari' hooks of several sizes: Japanese nominal sizes JNo.10, JNo.11, JNo.12, JNo.13, JNo.14 and JNo.16. On the assumption of geometrical similarity in the combination of upper jaw length u and hook width g at a given retention probability, a single master curve s(R) = exp (-14.42 + 8.85R)/(1 + exp [-14.42 + 8.85R]) was estimated in terms of relative upper jaw length to hook width, R = u/g, using the SELECT method based on a multinomial distribution. The relative upper jaw length for 50% retention is 1.63, and the selection range is 0.25. Almost all fish over 300 mm in total length were retained by a hook of size JNo.12, but smaller fish with less commercial value were also caught. Moreover, JNo.10 hooks catch fish with total lengths of 250 mm efficiently. This indicates that JNo.10 and JNo.12 hooks that are currently used are too small to optimize yield per recruit and also for resource conservation.