Turkey's ambitious Istanbul Canal project aims to bypass the historic, restrictive Bosporus shipping lanes.

Nature · Published 30 September 2026 Swipe more like this →

In short: Spanning 45 kilometers, the proposed Istanbul Canal would create an artificial island between Europe and Asia. While officials argue it will relieve dangerous maritime congestion and modernize transit, critics warn of severe environmental degradation, seismic risks, and potential geopolitical shifts regarding the long-standing Montreux Convention on naval passage.

The Istanbul Canal is a massive infrastructure project designed to connect the Black Sea to the Sea of Marmara, effectively creating a new waterway to bypass the Bosporus. First proposed in various forms as early as the 16th century under Sultan Suleiman the Magnificent, the modern iteration was officially announced by President Recep Tayyip Erdoğan in 2011. The canal is planned to be 45 kilometers long, with a depth of 20.75 meters and a surface width of 360 meters, intended to accommodate large vessels.

Proponents emphasize the need to reduce the heavy traffic currently burdening the Bosporus, which handles roughly 41,000 vessels annually, including 8,000 tankers. By providing an alternative route, the government hopes to minimize accident risks and generate significant revenue through transit fees. However, the project faces intense scrutiny. Critics, including scientific teams led by experts like Prof. Dr. Naci Görür, argue that the Environmental Impact Assessment fails to address critical issues such as the destruction of water resources, the loss of biodiversity, and the potential for increased seismic vulnerability in a region already prone to earthquakes.

Geopolitically, the canal is highly controversial because it may allow Turkey to circumvent the 1936 Montreux Convention. This treaty currently limits the tonnage and number of warships from non-Black Sea powers entering the region. By creating a waterway not subject to these restrictions, Turkey could gain greater autonomy over naval traffic. With an estimated cost of ₺75 billion, or US$10 billion, the project remains a flashpoint between those prioritizing economic and strategic expansion and those fearing irreversible ecological and safety consequences for Istanbul.

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