Checklist of Cartilaginous Species with Current Status and Conservation Strategies in Turkish Marine Waters

Cartilaginous fishes (Chondrichthyes) have 1282 species of sharks, batoids, and chimaeras worldwide. The class Chondrichthyes comprises 1226 species under the subclass Elasmobranchii and 56 species under the subclass Holocephali. The Mediterranean, particularly known for its rich diversity of cartilaginous species, is expected to suffer the most severe global decline in the number, diversity, and distribution of these species as a result of overfishing, with some species even facing extinction. The Mediterranean ecosystem is home to 89 cartilaginous species, containing 49 sharks, 38 batoids, and 2 chimaeras species. There are a total of 71 cartilaginous fish species in Turkish marine waters, 70 of which are elasmobranchs (38 shark and 32 batoid species) and 1 is a chimaera. Cartilaginous fishes are not the target of commercial fisheries in Türkiye, but are often unintentionally captured as bycatch through trawl, gillnet, and longline fisheries. Based on the IUCN Red List criteria, 27% of cartilaginous species are categorized as Vulnerable (VU), 26% as Endangered (EN), and 16% as Critically Endangered (CR) in Turkish marine waters. The remaining species are classified as follows: 14% as Near Threatened (NT), 13% as Least Concern (LC), and 4% as Data Deficient (DD). Numerous studies have been conducted in Turkish marine waters on the bio-ecology of cartilaginous species to support regulations to improve their conservation; however, genetic studies remain quite limited.