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Elasmobranchs longline fisheries in the Gulf of Gabès (southern Tunisia)

Published online by Cambridge University Press:  10 September 2013

K. Echwikhi ,
B. Saidi  and
M.N. Bradai
K. 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
B. Saidi
Affiliation:
National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia
M.N. Bradai
Affiliation:
National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia
*
Correspondence should be addressed to: K. Echwikhi, National Institute of Sea Sciences and Technologies, PO Box 1035, 3018 Sfax, Tunisia email: [email protected]
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Abstract

In Tunisia, elasmobranch landings have decreased substantially in recent years. Generally, species-specific information is largely unavailable for artisanal fisheries, but it is essential to increase knowledge and to ensure proper management of these species. This study analysed elasmobranch catches with longline fishery in the Gulf of Gabès. In total, 21 and 20 pelagic and bottom longline fishing trips were conducted, respectively, from July to September in 2007 and 2008. A total of eight elasmobranch species were caught: four batoids and four sharks. Pelagic longline captures were hooked externally while a high number of individuals captured with bottom longline were hooked internally. Discards due essentially to low commercial value and size represented 7.6% of total number of elasmobranch specimens caught. Longline landings in the Gulf of Gabès were principally composed of sandbar shark, Carcharhinus plumbeus, representing, respectively, 94.14% and 21.17% in number of pelagic and bottom longline captures. The importance of rhinobatids and Mustelus capture with bottom longline reflect their abundance in this area compared to other Mediterranean zones. Juveniles, including neonates with umbilical scars, dominated carcharhnids specimens, while smoothhound and guitarfish captures were dominated by mature individuals. Mitigation measures based on gear modifications, size limits and delineated nursery areas in the Gulf of Gabès should be developed to protect these vulnerable species.

Keywords

elasmobranchlonglinecaptureGulf of Gabèsfishery
Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 94 , Issue 1 , February 2014 , pp. 203 - 210
Copyright
Copyright © Marine Biological Association of the United Kingdom 2013 

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References

REFERENCES

Aldebert, Y. (1997) Demersal resources of the Gulf of Lions (NW Mediterranean) impact of exploitation on fish diversity. Vie et Milieu 47, 275–284.Google Scholar
Barker, M.J. and Schluessel, V. (2005) Managing global shark fisheries: suggestions for prioritizing management strategies. Aquatic Conservation: Marine and Freshwater Ecosystems 15, 325–347.CrossRefGoogle Scholar
Bonfil, R. (1999) Marine protected areas as shark fisheries management tool. In Seret, B. and Sire, J.Y. (eds) Proceedings of the 5th Indo-Pacific Fish Conference, Noumea, New Caledonia, 3–8 November 1997. Paris: Société Française d'Ichtyologie, Institut de Recherche pour le Développement, pp. 217–230.Google Scholar
Bradaï, M.N., Saïdi, B., Bouaïn, A., Guelorget, O. and Capapé, C. (2005) The Gulf of Gabès (Southern Tunisia, Central Mediterranean): a nursery area for sandbar shark, Carcharhinus plumbeus (Nardo, 1827) (Chondrichthyes: Carcharhinidae). Annales, Series Historia Naturalis 15, 187–194.Google Scholar
Bradaï, M.N., Saïdi, B., Enajjar, S. and Bouaïn, A. (2006) The Gulf of Gabès: a spot for the Mediterranean elasmobranches. In BaşUsta, N., Keskin, Ç., Serena, F. and Seret, B. (eds) The Proceedings of the Workshop on Mediterranean Cartilaginous Fish with Emphasis on Southern and Eastern Mediterranean. Istanbul: Turkish Marine Research Foundation, Publication No. 23, pp. 107–117.Google Scholar
Brewer, D., Eayrs, S., Mounsey, R. and Wang, Y.G. (1996) Assessment of an environmentally friendly, semi-pelagic fish trawl. Fisheries Research 26, 225–237.CrossRefGoogle Scholar
Capapé, C. (1974) Contribution à la biologie des Rajidés des côtes tunisiennes. II. Raja radula Delaroche 1809. Répartition géographique et bathymétrique, sexualité, reproduction et fécondité. Archive Institut Pasteur Tunis 51, 211–228.Google Scholar
Capapé, C. (1989) Les Sélaciens des côtes méditerranéennes: aspects généraux de leur écologie et exemples de peuplements. Océanis 15, 309–330.Google Scholar
Capapé, C., Hemida, F., Seck, A.A., Diatta, Y., Guélorget, O. and Zaouali, J. (2003) Distribution and reproductive biology of the spinner shark, Carcharhinus brevipinna (Müller and Henle, 1841) (Chondrichthyes: Carcharhinidae). Israel Journal of Zoology 49, 269–286.Google Scholar
Cavanagh, R.D. and Gibson, C. (2007) Overview of the conservation status of cartilaginous fishes (chondrichthyans) in the Mediterranean Sea. Gland and Malaga: IUCN.CrossRefGoogle Scholar
Enajjar, S., Bradaï, M.N. and Bouaïn, A. (2008) New data on the reproductive biology of the common guitarfish of the Gulf of Gabès (southern Tunisia, central Mediterranean). Journal of the Marine Biological Association of the United Kingdom 88, 1063–1068.CrossRefGoogle Scholar
Enajjar, S., Bradaï, M.N. and Bouaïn, A. (2012) Age, growth and sexual maturity of the blackchin guitarfish Rhinobatos cemiculus in the Gulf of Gabès (southern Tunisia, central Mediterranean). Cahiers de Biologie Marine 53, 17–23.Google Scholar
European Commission (2009) On a European Community Action Plan for the conservation and management of sharks. 5 February 2009. Brussels: COM.Google Scholar
Ferretti, F., Myers, R.A., Sartor, P. and Serena, F. (2005) Long term dynamics of the chondrichthyan fish community in the upper Tyrrhenian Sea. ICEs, 2005. Theme session on elasmobranch fisheries science (N), ICES Document CM 2005/N: 25. Aberdeen, 25pp.Google Scholar
Ferretti, F., Myers, R.A., Serena, F. and Lotze, H.K. (2008) Loss of large predatory sharks from the Mediterranean Sea. Conservation Biology 22, 952–964.CrossRefGoogle ScholarPubMed
Fogarty, M.J. and Murawski, S.A. (1998) Large-scale disturbance and the structure of marine systems: fishery impacts on Georges Bank. Ecological Applications 8, 6–22.CrossRefGoogle Scholar
Fonteyne, R. and M'Rabet, R. (1992) Selectivity experiments on sole with diamond and square mesh cod-ends in the Belgian coastal beam trawl fishery. Fisheries Research 13, 221–233.CrossRefGoogle Scholar
Garla, R.C., Chapman, D.D., Shivji, M.S., Wetherbee, B.M. and Amorim, A.F. (2006a) Habitat of juvenile Caribbean reef sharks, Carcharhinus perezi, at two oceanic insular marine protected areas in the southwestern Atlantic Ocean: Fernando de Noronha Archipelago and Atol das Rocas. Brazil Fisheries Research 81, 236–241.CrossRefGoogle Scholar
Garla, R.C., Chapman, D.D., Wetherbee, B.M. and Shivji, M. (2006b) Movement patterns of young Caribbean reef sharks, Carcharhinus perezi, at Fernando de Noronha Archipelago, Brazil: the potential of marine protected areas for conservation of a nursery ground. Marine Biology 149, 189–199.CrossRefGoogle Scholar
Gonçalves, J.M.S., Stergiou, K.I., Hernando, J.A., Puente, E., Moutopoulos, D.K., Arregi, L., Soriguer, M.C., Vilas, C., Coelho, R. and Erzini, K. (2007) Discards from experimental trammel nets in southern European small-scale fisheries. Fisheries Research 88, 5–14.CrossRefGoogle Scholar
Hall, S.J. (1999) The effects of fishing on marine ecosystems and communities. Oxford: Blackwell Science.Google Scholar
Hemida, F., Seridji, R., Ennajar, S., Bradai, M.N., Collier, E., Guelorget, O. and Capapé, C. (2003) New observations on the reproductive biology of the pelagic stingray, Dasyatis violacea Bonaparte, 1832 (Chondrichthyes: Dasyatidae) from the Mediterranean Sea. Acta Adriatica 44, 193–204.Google Scholar
Heupel, M.R., Carlson, J.K. and Simpfendorfer, C.A. (2007) Shark nursery areas: concepts, definition, characterization and assumptions. Marine Ecology Progress Series 337, 287–297.CrossRefGoogle Scholar
Jukic-Peladic, S., Vrgoc, N., Krstulovic-Sifner, S., Piccinetti, C., Piccinetti-Manfrin, G., Marano, G. and Ungaro, N. (2001) Long-term changes in demersal resources of the Adriatic Sea: comparison between trawl surveys carried out in 1948 and 1998. Fisheries Research 53, 95–104.CrossRefGoogle Scholar
Kokko, H., Linsdstrom, J. and Ranta, E. (2001) Life histories and sustainable harvesting. In Reynolds, J.D., Mace, G.M., Redford, K.H. and Robinson, J.G. (eds) Conservation of exploited species. Cambridge: Cambridge University Press, pp. 301–322.Google Scholar
Lipej, L., Makovec, T., Soldo, A. and Ziza, V. (2000) Records of the sandbar shark Carcharhinus plumbeus, (Nardo, 1827) in the Gulf of Trieste (Northern Adriatic). Annales, Series Historia Naturalis 10, 199–206.Google Scholar
Madsen, N., Tschernij, V., Hansen, K. and Larsson, P.O. (2006) Development and testing of a species-selective flatfish otter trawl to reduce cod by-catches. Fisheries Research 78, 298–308.CrossRefGoogle Scholar
Musick, J.A. (1999) Ecology and conservation of long-lived marine animals. In Musick, J.A. (ed.) Life in the slow lane: ecology and conservation of long-lived marine animals. Bethesda, MD: American Fisheries Society, Symposium 23, pp. 1–10.CrossRefGoogle Scholar
Musick, J.A., Burgess, G., Cailliet, G., Camhi, M. and Fordman, S. (2000) Management of sharks and their relatives (Elasmobranchii). Fisheries 25, 9–13.2.0.CO;2>CrossRefGoogle Scholar
Saïdi, B., Bradaï, M.N. and Bouaïn, A. (2008) Reproductive biology of the smooth-hound shark Mustelus mustelus in the Gulf of Gabès (south-central Mediterranean Sea). Journal of Fish Biology 72, 1343–1354.CrossRefGoogle Scholar
Saïdi, B., Bradaï, M.N. and Bouaïn, A. (2009) Reproductive biology and diet of Mustelus punctulatus (Risso, 1826) (Chondrichthyes: Triakidae) from the Gulf of Gabès, central Mediterranean Sea. Scientia Marina 73, 249–258.CrossRefGoogle Scholar
Saïdi, B., Bradaï, M.N., Bouaïn, A., Guéorget, O. and Capapé, C. (2005) Reproductive biology of the sandbar shark, Carcharhinus plumbeus (Chondrichthyes: Carcharhinidae) from the Gulf of Gabès (southern Tunisia, Central Mediterranean). Acta Adriatica 46, 47–62.Google Scholar
Simpfendorfer, C.A. (1999) Demographic analysis of the dusky shark fishery in southwestern Australia. In Musick, J.A. (ed). Life in the slow lane: ecology and conservation of long-lived marine animals. Bethesda, MD: American Fishery Society, Symposium 23, pp. 149–160.Google Scholar
Smith, W.D., Cailliet, G.M. and Cortés, E. (2008) Demography and elasticity of the diamond stingray, Dasyatis dipterura: parameter uncertainty and resilience to fishing pressure. Marine Freshwater Research 59, 575–586.CrossRefGoogle Scholar
Walker, P., Cavanagh, R.D., Ducrocq, M. and Fowler, S.L. (2005) Regional Overviews: Northeast Atlantic (including Mediterranean and Black Sea). In Fowler, S.L., Cavanagh, R.D., Camhi, M., Burgess, G.H., Cailliet, G.M., Fordham, S.V., Simpfendorfer, C.A. and Musick, J.A. (eds) Sharks, rays and chimaeras: the status of the chondrichthyan fishes. Gland and Cambridge: IUCN/SSC Shark Specialist Group, IUCN, pp. 71–95.Google Scholar
Wetherbee, B.M. and Cortés, E. (2004) Food consumption and feeding habits. In Carrier, J.C., Musick, J.A. and Heithaus, M.R. (eds) Biology of sharks and their relatives. Boca Raton, FL: CRC Press, pp. 225–246.CrossRefGoogle Scholar
Zar, J.H. (1998) Biostatistical analysis. 4th edition. Upper Saddle River, NJ: Prentice-Hall.Google Scholar