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Interactions of loggerhead turtle with bottom longline fishery in the Gulf of Gabès, Tunisia

Published online by Cambridge University Press:  13 July 2011

Khaled Echwikhi ,
Imed Jribi ,
Mohamed Nejmeddine Bradai  and
Abderrahmen Bouain
Khaled Echwikhi*
Affiliation:
National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia Sfax Faculty of Sciences PO Box 1171, 3000 Sfax, Tunisia
Imed Jribi
Affiliation:
Sfax Faculty of Sciences PO Box 1171, 3000 Sfax, Tunisia
Mohamed Nejmeddine Bradai
Affiliation:
National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia
Abderrahmen Bouain
Affiliation:
Sfax Faculty of Sciences PO Box 1171, 3000 Sfax, Tunisia
*
Correspondence should be addressed to: K. Echwikhi, National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia email: chouikhikhaled@yahoo.fr
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Abstract

In the Gulf of Gabès (Tunisia), a fleet of bottom longliners operates in summer and in the beginning of autumn targeting groupers. This fleet interacts with loggerhead turtles. During twenty trips in which 48,020 hooks were deployed, a total of 16 loggerheads were captured, most of them were juveniles, and direct mortality was estimated to be 43.75%. During the fishing operation, the hauling of the gear started one to three hours after and sometimes occurred immediately after setting. Results obtained show that the soak time did not affect the capture of turtles and target species, whereas it influenced the mortality rate of turtles. Bottom longline should be studied more in depth throughout the Mediterranean Sea, as well as parameters related to the interaction with sea turtles. However, mitigation measures to reduce turtle by-catch are urgently needed. In this way, we propose: (i) reducing the fishing soak time; (ii) experimenting with gear modification such as the use of circle hooks; and (iii) conducting an awareness campaign aimed at fishermen to show them how to deal with turtle by-catch.

Keywords

bottom longlinecatch rateloggerhead turtlemortalitysoak time
Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 92 , Issue 4: Coral Reefs, the Aquarium Trade and the Maritime Industry , June 2012 , pp. 853 - 858
Copyright
Copyright © Marine Biological Association of the United Kingdom 2011

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