Comprehensive Monitoring of Bottlenose Dolphins (Tursiops truncatus) and Common Dolphins (Delphinus delphis) in the Black Sea and the Istanbul Strait Using Photo-Identification “CetaFin Project”
The most observed species of the Delphinidae family in Turkish waters are bottlenose dolphin (Tursiops truncatus) and common dolphin (Delphinus delphis). Both of these species are distributed across all of Turkish waters. Their populations are threatened by anthropogenic factors, including bycatch, decline in prey availability due to overfishing, pollution and disease related mass mortalities. Although both migratory and resident populations have been identified for these species, studies conducted in Turkish waters are limited and insufficient to fully understand their population dynamics.
To gain knowledge about site fidelity and population dynamics of these species help us understand their usage of habitat and how they are affected by anthropogenic factors. This project aims to study the long term site fidelity of bottlenose and common dolphins using photo identification. We will focus on three regions along the Turkish Black Sea coast and the Istanbul Strait. Each of these regions represents different levels of anthropogenic impacts. Visual assessment of the body injuries, morphological changes and determine their body condition scores will be used as indicators of potential threats. To date, most of the cetacean studies conducted in the Black Sea are focused on understanding the current status. With the results of this study, the migratory movements of bottlenose and common dolphins in the southern Black Sea will be revealed for the first time.
The project of which we are a partner, plans to conduct boat-based surveys over a two year period in the Istanbul Strait, Sinop and Zonguldak regions using small vessels. The surveys will be conducted in suitable weather conditions. Dorsal fin pictures will be taken using DSLR and SLR cameras equipped with telephoto lenses and when it is possible, aerial images will be taken using drones. Individual dolphins will be identified based on their unique dorsal fin markings and photographs of identified individuals will be cataloged according to standardized protocols. The data collected from Istanbul, Sinop and Zonguldak will be analyzed using QGIS and relevant packages within the R software. The results will help us understand the local abundance and distribution, site fidelity, temporal and spatial movements and exposure to human based activities’ pressures. This versatile approach will offer a comprehensive understanding of the ecological dynamics of the dolphins in the region. If the data are suitable, they will also be evaluated for a preliminary study on the population health and welfare of bottlenose dolphins and mallards. The project will have one coordinator, 7 researchers, one postdoctoral fellow and 2 advisors. The project proposal is planned for 36 months. The results of this study will contribute baseline data for conservation strategies for these two cetacean species, which have been under national and international protection since 1983 and this data will be provided as a resource for further scientific research. The resulting photo identification catalogues will serve as valuable references for future studies of Turkish waters and neighbouring seas. The data obtained will help better understand the population dynamics of bottlenose and common dolphins in Turkish waters. It is foreseen that two articles will be published in SCI indexed journals from the results.
