Producing Local Common Bottlenose Dolphin Abundance Estimates to Fill Species Knowledge Gaps in the Eastern Mediterranean Surrounding Türkiye

ABSTRACT The IUCN Red List status of the Mediterranean subpopulation of common bottlenose dolphins has recently been upgraded to Least Concern. Although large‐scale surveys provide crucial information on the population status, local efforts often allow more robust estimation and the ability to monitor population trends. The current study used a standard line transect survey design during 21 surveys conducted between April 2018 and July 2025. The research boat covered 31,717 km with a survey coverage of 32,628 km 2 across a total of 214 days. Overall, 93 encounters of bottlenose dolphins were recorded, 45 of which occurred while the vessel was ‘on‐effort’, with a mean group size of four. We found no significant differences in the number of sightings between season and year when accounting for days of survey effort. Encounters were most frequent in the easternmost region of Türkiye. The abundance estimate of bottlenose dolphins after 500 bootstraps in the Eastern Mediterranean Sea of Türkiye was 1642 ± 440 individuals (CV = 0.27, 95% CI [749–2447]), varying considerably from previous basin‐wide estimates. The local population estimates produced by this study extend our understanding of the status of bottlenose dolphins in the Eastern Mediterranean and contribute to basin‐wide estimates.