Bechir Saidi

By Mohamed Nejmeddine Bradai, Samira Enajjar and Bechir Saidi

Cartilaginous fishes are a very ancient group; Sharks have lived on Earth for about 500 million years, since long before the dinosaurs. They have been able to survive and overcome five mass extinctions since their appearance. They play in fact a key role in maintaining the balance of marine ecosystems. More than 97% of the shark population has disappeared in the last two centuries. Currently, a high percentage is threatened, many are data-deficient. Many menaces face sharks, but fishing pressure seems to be most critical. This chapter focuses on the current status of cartilaginous fishes and progress on conservation measures and actions taken mainly through regional plans.

Part of the book: Sharks

By Samira Enajjar, Bechir Saidi and Mohamed Nejmeddine Bradai

The authors have compiled published information on taxonomy, distribution, status, statistics, fisheries, bycatch, biologic, and ecologic parameters mainly on food and feeding habits and reproductive biology of elasmobranchs along the Tunisian coasts. This bibliographic analysis shows that cartilaginous species, including sharks and rays are by far the most endangered group of marine fish, with 63 species, about 53% of all are critically endangered, endangered, or vulnerable. Overfishing, fishing practices, and habitat degradation are leading to dramatic declines of these species. Biologic parameters concern a few species primarily in the Gulf of Gabes. Therefore, recommendations to fill gaps in order to protect and manage elasmobranchs stocks are proposed in this chapter.

Part of the book: Sharks