Applying genetic techniques to study remote shark fisheries in northeastern Madagascar

Background and aims. The shark fisheries of Madagascar remain largely unstudied. Remoteness makes fisheries monitoring challenging while the high value of shark fins combined with the extreme poverty in Madagascar creates intensive pressure on shark resources. Materials and methods. We use DNA barcoding and species-specific PCR assays to characterize shark fisheries in Antongil Bay in northeastern Madagascar. Results. The 239 samples taken from individuals collected in 2001 and 2002 correspond to 19 species. The four most common species were Sphyrna lewini, Rhizoprionodon acutus, Carcharhinus brevipinna, and C. sorrah. Antongil Bay may be a breeding area for C. brevipinna, C. leucas, and S. lewini. Conclusion. Local names are generally not a useful proxy for monitoring the species harvested in the fishery. Conservation efforts should characterize species exploitation at present, create spatial and temporal fishing restrictions to protect endangered species, and restrict large mesh gillnets.