How can the feeding habits of the sand tiger shark, Carcharias taurus, affect the success of conservation programs?

LUIS O. LUCIFORA; VERÓNICA B. GARCÍA; ALICIA H. ESCALANTE

Montreal

Congreso; 24th Annual Meeting of the American Elasmobranch Society and 88th Joint Meeting of Ichthyologists and Herpetologists; 2008

The sand tiger shark, Carcharias taurus, is one of the most threatened species of shark worldwide. While recovery programs are now in effect, how they can be furthered or hampered by the feeding ecology of sand tigers is unknown. Using data collected from a north Patagonian recreational fishery, we analyzed the feeding habits in relation with size, sex, and maturity stage of the predator; assess how prey capture behaviour may affect the success of catch-and-release measures; and estimate prey selection and diet overlap with fishery landings. Sand tiger sharks preyed mainly on teleosts and elasmobranchs; benthic elasmobranchs were consumed in higher number as sharks become larger. Minimal prey handling resulted in rapid hook swallowing and, consequently, in severe damage to the internal organs in most individuals. Sand tiger sharks fed selectively on skates (Rajidae), Sciaenid fishes, flatfishes (Paralichthyidae), and smooth-hound (Mustelus schmitti) and angel (Squatina guggenheim) sharks. Selected prey were all predominant in fishery landings, resulting in an almost complete (>90%) overlap of the diet with fisheries. We conclude that ignoring the feeding habits of sand tigers ?characterized by little prey handling, low plasticity, high selectivity, and high overlap with fisheries? could substantially affect the success of recovery programs.