SEASONAL ARRIVAL AND FEEDING OF INJURED COASTAL SHARKS AT FISH FARMS IN THE EASTERN MEDITERRANEAN   

Seasonal arrival and feeding of injured coastal sharks at fish farms in the eastern Mediterranean   

Adi Barash, Renanel Pickholtz, Hagai Nativ, Shahar Malamud, Aviad Scheinin, Dan Tchernov

Leon Charney School of Marine Sciences, University of Haifa, Haifa, ISRAEL
School of Zoology, Tel Aviv University, Tel Aviv, ISRAEL
Morris Kahn Marine Research Station, Sdot-Yam, ISRAEL

Abstract

Every summer coastal sharks (mostly sandbar sharks, Carcharhinus plumbeus) come to feed at open-sea fish farms near the Israeli coast, ever since their opening. Three of these sharks appear to suffer injuries of various degrees. At least one of the injured individuals, which suffers from a broken lower jaw, has been sighted at the fish farms every year since 2011. Providing a constant source of food to supplement feeding of wildlife has been shown to have both negative and positive impacts on wild populations and individuals. It may be possible that injured sharks, who have reduced abilities to find food in the wild, rely on such human related food sources to survive. Implications on the long-term effect of provisional feeding on sharks are discussed.

Keywords: Carcharhinus plumbeus, provisional feeding, elasmobranch, aquaculture, Eastern Mediterranean

pdf-dl icon

References

Dulvy, N., Allen, D., Ralph, G., Walls, R. (2016) The Conservation Status of Sharks, Rays and Chimaeras in the Mediterranean Sea (Brochure). IUCN, Malaga, Spain.

Dulvy, N.K., Fowler, S.L., Musick, J.A., Cavanagh, R.D., Kyne, P.M., Harrison, L.R., Carlson, J.K., Davidson, L.N., Fordham, S.V., Francis, M.P. (2014) Extinction risk and conservation of the world’s sharks and rays. Elife 3. doi: 10.7554/eLife.00590

Ferretti, F., Myers, R.A., Serena, F., Lotze, H.K. (2008) Loss of large predatory sharks from the Mediterranean Sea. Conservation Biology 22: 952-964.

Mandelman, J.W., Cooper, P.W., Werner, T.B., Lagueux, K.M. (2008) Shark bycatch and depredation in the US Atlantic pelagic longline fishery. Reviews in Fish Biology and Fisheries 18: 427.

McAuley, R.B., Simpfendorfer, C.A., Hall, N.G. (2007) A method for evaluating the impacts of fishing mortality and stochastic influences on the demography of two long-lived shark stocks. ICES Journal of Marine Science 64: 1710-1722.

Molina, J.M., Cooke, S.J. (2012) Trends in shark bycatch research: current status and research needs. Reviews in Fish Biology and Fisheries 22: 719-737.

Murray, M.H., Becker, D.J., Hall, R.J., Hernandez, S.M. (2016) Wildlife health and supplemental feeding: a review and management recommendations. Biological Conservation 204: 163-174.

Orams, M.B. (2002) Feeding wildlife as a tourism attraction: a review of issues and impacts. Tourism Management 23: 281-293.

Papastamatiou, Y.P., Itano, D.G., Dale, J.J., Meyer, C.G., Holland, K.N. (2011) Site fidelity and movements of sharks associated with ocean-farming cages in Hawaii. Marine and Freshwater Research 61: 1366-1375.

Pemberton, D., Brothers, N., Copson, G. (1991) Predators on marine fish farms in Tasmania. Papers and Proceedings of the Royal Society of Tasmania 25: 33-35.

Ward-Paige, C.A., Worm, B. (2017) Global evaluation of shark sanctuaries. Global Environmental Change 47: 174-189.

Worm B., Davis B., Kettemer, L., Ward-Paige, C.A., Chapman, D., Heithaus, M.R., Kessel, S.T., Gruber, S.H. (2013) Global catches, exploitation rates, and rebuilding options for sharks. Marine Policy 40: 194-204.