Anthropogenic impact on the shores and the bottom of the Jebriyan bay in the Northwestern part of the Black Sea

The Jebriyan Bay is located in the northern part of the Kiliya Danube Delta, at a junction of the delta cone and the indigenous coast. This is a zone of very high anthropogenic impact on the Danube Biosphere Reserve. The two opposite shores of this bay are fundamentally different. Along the northern shore, the Northwest coastal sand sediment flows discharge from the Cape of the Great Fontanne to the Jebriyan Bay. That is why the northern coast of the bay is made up of sandy forms of coastal topography (marine accumulative terrace and spit). The southern coast is deltaic; composed of a mixture of muddy, siltstone and sandy sediments. The area of the bay is limited to isobaths –11 m and is about 80 km2. The bottom of the bay has a gentle relief, made up of smooth outlines, with an average depth of 6.2 m. The shape of the transverse profile of the underwater slope is mostly convex. The natural system of the bay was affected by fishing, recreation, shipping and industrial sand production on coastal accumulative landforms. Coastal fishing uses a system of fixed bottom seines and small motorized floating equipment. Recreational facilities are designed to serve about 350 thousand people during the warm period each year. The impact of shipping was expressed in the construction and operation of the seaport of Ust-Dunaysk, together with suitable canal and the technical canal between the sea and the branch of the delta breakthrough the system of the large Ochakov branch. The ladle port had an area of about 1.5 km2, a maximal depth of 16 m, and an average depth of 13.7 m. The trough was connected to the Ochakov branch of the Danube Delta by a technical canal with a depth of 4 m. Vessels could enter the harbor of Ust-Danube through an access navigation channel with a depth of 11–12 m and a bottom width of 125 m. The port was used for the transshipment of large containers, general forest cargo from ocean vessels (displacement of 60–100 thousand tons) on regular sea lines from the countries of Southeast Asia to the Black Sea, to the Danube and further to the countries of Central Europe and to the ports of the North and the Baltic Seas. But it was unfortunate that the port construction site did not last as expected. Between 1980–2010 the harbor and approach canal of Ust-Dunaysk were filled with Danube river sediments. The example of Jebriyan Bay has shown that when executing any type of sustainable nature management project, it is very important to take into account the natural milieu.