ECOLOGICAL CHANGES IN THE SEA OF MARMARA, Melek İşinibilir,Ahmet E. Kıdeyş,Alenka Malej, Editör, Istanbul University Press, İstanbul, ss.819-845, 2024
A review of general ichthyological inventories and shark- and batoid-spesific studies was revealed the historical
and contemporary presence of 20 species of sharks and 16 species of batoids in the Sea of Marmara. Contemporary
occurrences of 15 out of 20 species of sharks were confirmed following recent surveys or ichthyological records, and
the remaining 5 species of sharks are considered either questionable or absent. Similarly, since 4 out of 16 batoids
are considered questionable, the current batoid fauna of the region is included 12 species. Therefore, elasmobranch
inventory of this small inland sea is consisted of 27 species with confirmed records. For the moment it is unpredictable
how the cartilaginous fishes in the Sea of Marmara will be affected from the threats of the worsening conditions of
oxygen depletion, as a result of their forced migration in habitable oxygenated areas of continental shelf, these
regions may also turn into a ‘habitat trap’ for these species, where they can be negatively affected by bycatch. It is a
serious threat that fisher-cartilaginous fish competition may become dramatically aggressive because of the increased
pressure of predatory chondrichthyans on commercially high valued species due to the assumed habitat compression.
This threat can also trigger a perception that endanger the survival of cartilaginous fishes, due to increasing predatory
pressure on high valued species. When all the available information is brought together, it is clear that management
plans aiming to protect the sharks and batoids of the Sea of Marmara should not be restricted to prohibit intentional
fishing of the species, but an ecosystem management approach to protect the critical habitats of chondrichthyans is
needed. Fishermen should also be trained and promoted to release the entangled or hooked sharks and batoids as
quick as possible and handle them properly.