The Danube Delta is a labyrinth of water and land shared between Romania and Ukraine, made up of countless lakes, channels and islands lying at the end of the 2860 km-long river of the same name. The Danube River rises in the Black Forest mountains in Germany and along its course, passes through 10 countries: Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, Moldova and Ukraine before emptying into the Black Sea.

The Danube Delta covers an area of some 4300 sq km and is known for its abundance of birdlife, as it hosts more than 300 species of birds as well as 45 species of freshwater fish in its numerous lakes and marshes. In 1991, the Romanian part of the Danube Delta became part of UNESCO’s list of World Heritage Sites.

In this true-colour image, captured in April 2020, the vast reed beds can be seen in shades of brown which is typical during this time of year. The Danube is visible (in the left of the image) before splitting into the various channels and branches that flow through the reeds and grassland before reaching the Black Sea. The distinct light-green colours in the sea are likely due to sediment being carried by the river.

Just south of the Danube Delta lie the lagoons of Razim (Razelm) and Sinoe, visible in emerald green owing to a high concentration of algae. This lagoon complex was formed with the help of the Danube’s alluvial deposits and the gradual eastward movement of the coastal currents caused by the advancement of the delta.

In the top-right of the image lies the Sasyk, or Kunduk, Lagoon in southern Ukraine. The site has been designated as Ramsar Wetland Site as it is important for migrating, breeding and moulting waterbirds.

Data gathered by the Sentinel-2 satellites are used for monitoring land use and changes, land management, agriculture, forestry and natural disasters (floods, forest fires, landslides and erosion). Offering colour vision for the Copernicus programme, Sentinel-2 delivers optical images from the visible to short-wave infrared range of the electromagnetic spectrum.

This image is also featured on the Earth from Space video programme.