Fish Morphology and Barrier Trap Bar Spacing in Lagoon Fisheries along the Aegean Coast of Turkey

• Main Authors: TOSUNOĞLU, Zafer, KARAKUZU, Ravda Önem, GÖKÇE, Gökhan, KAYKAÇ, M. Hakan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Mersin Üniversitesi 2018
• Subjects: Coastal lagoon,barrier trap,openness,fish morphology; European eel
• Online Access: https://dergipark.org.tr/tr/pub/medfar/issue/37150/410487

The most important fishing rule implemented in Turkishlagoon fishery is distance between the reeds (stick) of the barrier trapsshould not be less than 3 cm. Based on this arrangement, usually 3 cm barspacing reeds and sometimes 3 cm square mesh wires are used in lagoon barriertraps. The body shape of fish may be the most important factor necessary tounderstand the consequences of changes in barrier trap selectivity. For thisreason, data were collected to determine the relevant dimensions of fish bodyin relation to openness of a barrier trap of coastal lagoons along the Aegeancoast of Turkey in 2013. As Minimum Landing Size (MLS) was built on TotalLength (TL) basis, regression analyses were carried out to find out therelationships between the TL and the other measured dimensions (width andheight) of the fish using least-square regression. Morphometric measurements offish species caught in barrier traps show a great variation. While all Common soleindividuals pass from the 3 distance with its width, all Flathead grey mulletand European sea bass individuals retained behind the sticks of the barriertrap. All Gilthead sea bream individuals under 25 cm TL pass the distance.However, many Golden grey mullet and European eel individuals retain at thebarrier traps with theirs width. The implemented 3 cm bar spacing inTurkish lagoon barrier traps is thought to be suitable only for sea bass with a1% reduction. However, the bar spacing is not suitable for Sea bream, Commonsole, European eel due to commercial loss and for Flat head grey mullet andGolden grey mullet capturing small individuals below their MLS. For thisreason, a graded barrier system with different bar spaces or regulationaccording to the biology of the fish species and migration seasons can benefitsustainable lagoon fishery. In this respect, the continuously changing distanceparadox in barrier traps will be overtaken in Turkey.