The Danube Delta Reserve and Twenty Years Over the Bystre Canal

The Danube River flows about 2,860 km before splitting into many branches to form a delta just short of the Black Sea. According to the Danube Biosphere Reserve, part of the National Academy of Sciences of Ukraine, the delta covers 5,640 km², of which 82% lies in Romania and 18% in Ukraine. The Ukrainian side of the delta is at the southwestern tip of Odesa Oblast, spreading out beyond the Kyliia branch (the Kyliia distributary), which forms the border with Romania.

A national reserve was established here in 1998, and that same year it was registered with UNESCO, together with the Romanian side, as a single biosphere reserve. At the same time, in 2004, an international dispute arose with Romania over a shipping channel through the reserve, the Bystre Canal. This article traces the reserve’s origins and the twenty years of dispute that followed.

The Kyliia Branch Delta, Still Growing Toward the Sea

According to the Danube Biosphere Reserve, the Danube splits into the Kyliia and Tulcea branches at a headland (Izmail Chatal) downstream of Izmail, with 49% of the water flowing through the northern Kyliia branch. The delta of the Kyliia branch below the town of Vylkove is the newest part of the Danube Delta as a whole — formed over roughly 400 years, with the strip facing the sea less than 150 years old. The reserve states that the Danube carries 42 to 84 million tonnes of silt to the sea each year, and that this deposition keeps extending the delta seaward.

The share of water flow differs between sources. The Internet Encyclopedia of Ukraine (IEU, first published 1984), from the Canadian Institute of Ukrainian Studies at the University of Alberta, states that about two-thirds of the Danube’s flow passes through the Kyliia branch. The Danube’s basin within Ukraine and the length of the border it forms are covered in our article on Ukraine’s rivers and climate.

The 1998 Presidential Decree and a Biosphere Reserve Spanning Two Countries

The Danube Biosphere Reserve was established under Presidential Decree No. 861/98 of August 10, 1998, based on the “Dunaiski Plavni” nature reserve that had existed in the Kyliia district of Odesa Oblast. The decree states its purpose as “preserving the Danube Delta’s unique natural complex in its natural state, and advancing international cooperation, scientific research, and environmental monitoring,” and places the reserve under the National Academy of Sciences. The area set out, including waters of the Black Sea, was 46,402.9 hectares, of which 22,662 hectares were transferred as land for the reserve’s own use, and 23,740.9 hectares were included within the reserve without being taken from their existing land users.

According to the reserve, UNESCO’s International Coordinating Council of the Man and the Biosphere (MAB) Programme added this reserve to the World Network on December 9, 1998, as part of the transboundary “Danube Delta” biosphere reserve spanning Romania and Ukraine. UNESCO’s page states that this transboundary reserve includes four Ramsar Convention wetlands: “Danube Delta” on the Romanian side, and “Kyliia Mouth,” “Lake Kuhurlui,” and “Lake Kartal” on the Ukrainian side.

Presidential Decree No. 117/2004 of February 2, 2004, expanded the reserve, adding 1,295 hectares in the Kyliia district and 3,850 hectares in the Tatarbunary district. The reserve gives its current total area as 50,252.9 hectares. UNESCO’s page on the Ukrainian side gives a different figure; the areas of Ukraine’s main nature reserves are compiled in a table in our article on nature reserves.

The Ramsar-listed “Kyliia Mouth” wetland (Site No. 113) was originally part of a wetland the Soviet Union registered on October 11, 1976, as “Danube Delta and Tendra and Yahorlyk Bays.” According to the Ramsar Convention Secretariat, this was split into three after Ukraine’s accession, in 1995, and in 2021 its boundaries were expanded, adding 12,100 hectares, bringing it to its current 44,904.3 hectares. More than 1% of the populations of both the Dalmatian pelican and the great white pelican are said to visit the site, and since 2009 work has been under way to remove embankments and restore island habitats.

Recorded Species

The Danube Biosphere Reserve publishes the following figures.

For the transboundary reserve as a whole, UNESCO’s page lists 312 important bird species and states that it holds Europe’s largest population of the Dalmatian pelican. The reserve states that its delta wetlands are important, on a European scale, to the survival of the European mink and the European wildcat.

The Bystre Canal and the Dispute Since 2004

In the early 2000s, Ukraine advanced a plan to open a deep-water channel linking the Danube to the Black Sea within its own delta. Known as the “Bystre Canal,” the route runs through the Bystre mouth (Novostambulske mouth), a branch off the Kyliia branch leading to the sea. According to the United Nations Economic Commission for Europe (UNECE), the plan’s first stage was completed in August 2004.

Half a year earlier, Presidential Decree No. 117/2004 of February 2, 2004, citing the aim of “restoring navigation in the Ukrainian part of the Danube Delta,” reclassified 348 hectares of protective strip along the Bystre mouth, 442 hectares along the Ochakiv mouth, and 230 hectares of Black Sea waters as an “anthropogenic landscape zone” within the reserve — a zone within the reserve where economic activity is permitted.

Romania, arguing that the project would have transboundary environmental effects, invoked the “inquiry procedure” of the Convention on Environmental Impact Assessment in a Transboundary Context (the Espoo Convention, 1991), notifying it on August 19, 2004. According to UNECE, this was the first, and remains the only, time this procedure has been used. An inquiry commission was formed, chaired by an emeritus professor from a Dutch university, with Romania and Ukraine each appointing one expert; after visiting both countries in May 2006, it delivered its unanimous conclusion to the two governments on July 10 that a significant adverse transboundary impact was likely.

The subsequent course of events, summarized from UNECE’s announcements, is as follows.

In October 2004, a joint fact-finding mission of the European Commission and international-treaty experts also visited the Bystre mouth (a report is posted on UNECE’s Inquiry Commission page). As a matter of the Convention’s procedure, this case was closed as of September 2026.

The Bystre Mouth Since the Full-Scale Invasion

When exports from Black Sea ports stopped because of Russia’s full-scale invasion, which began on February 24, 2022, the Danube ports and the Bystre mouth channel took on a greater role. Ukraine’s then Ministry of Communities, Territories and Infrastructure Development announced on February 17, 2023, that, under an order from the Izmail port authority dated February 16, the permitted draft for vessels had increased to 6.5 m from the 0 km point of the Bystre mouth to the 77 km point of the Kyliia branch, and to 7 m from 77 km to 116 km. It stated that the maximum draft at the start of the full-scale invasion had been 3.9 m.

The Ministry explained that cargo transshipment at the three ports of Izmail, Reni, and Ust-Dunaisk tripled in the year from March 2022, with more than 17 million tonnes of goods exported, including more than 11 million tonnes of food. It also stated that work on the Ukrainian side of the Danube is being carried out in cooperation with the European Commission, Romania, and the Danube Commission. The role of the Danube ports after Odesa’s port was halted by attacks in the summer of 2026 is covered in our article on grain export routes.