13.08.2019

Marmara Sea cetacean survey completed

After 5 days and 600 km surveyed, the research expedition on cetaceans in the Marmara Sea has come to an end. Preliminary results of the TUDAV-funded abundance and distribution survey: 38 sightings of dolphin and porpoise.

Seven experts from TUDAV, along with two Sailist crew, sailed more than 600 kilometres in five days in search of dolphins and porpoises in the Marmara Sea. The team started the survey from Izmit Bay, the eastern side of the survey area, and finalized at the entrance of the Çanakkale Strait following a number of zigzag-line transects.

Last summer, the ACCOBAMS Survey Initiative (ASI) project, coordinated by the ACCOBAMS Secretariat (the Agreement on the Conservation of Cetaceans in the Black Sea, the Mediterranean Sea and the adjacent Atlantic) was carried out to understand the distribution and abundance of Mediterranean cetaceans. In June and July this year, the “CeNoBS” project was realized to determine the distribution and abundance of cetaceans in the Black Sea. The expedition for the Marmara Sea was organized immediately after the Black Sea survey

This recent expedition is the first study carried out in 20 years after the project for the determination of marine mammal populations for the first time in the Marmara Sea in 1997-1999.

Study and the team

During the expedition, visual sightings were made for cetacean species such as bottlenose dolphin, common dolphin and harbour porpoise, as well as marine litter in the Marmara Sea.

Under the coordination of TUDAV President Prof. Bayram ÖZTÜRK, faculty members from Istanbul University’s Faculty of Aquatic Sciences, as well as the members of TUDAV Dr. Ayaka Amaha ÖZTÜRK, Assoc. Prof. Ayhan DEDE, Assoc. Prof. Arda M. TONAY, and veterinarians Dr. Erdem DANYER and Işıl AYTEMİZ DANYER from the Republic of Turkey’s Ministry of Agriculture and Forestry, Research Assistant Uğur ÖZSANDIKÇI from Sinop University’s Faculty of Fisheries and TUDAV staff Zeynep GÜLENÇ participated in the boat survey that covered the Marmara Sea.

Preliminary data

According to preliminary data, 38 dolphins and porpoise sightings were recorded in a scanned area of 800 kilometres in five days. Each sighting consisted of at least 1 and at most 18 individuals. In terms of species, common dolphins were observed only three times in very small numbers compared to other two species (bottlenose dolphins and harbour porpoises). 400 records of floating marine litter indicated that there are more litter than cetaceans in the Marmara Sea.. Population size analyses of dolphins are still in progress.