Foto de stock - 23 March 2021, Brandenburg, Werder (Havel): Three million glass eels are handed over to commercial fishermen in transport crates and released by them into the Havel and its tributaries. The stocking operations are necessary because the natural upstream migration of young eels via the Elbe has come to an almost complete standstill as a result of industrialisation and locks. The glass eels were caught on the French Atlantic coast. By the time they reach there, they have already travelled some 4,500 kilometres from the Gulf of Mexico through the Atlantic on their one to two year migration. Photo: Jens Kalaene/dpa-Zentralbild/ZB. - Werder (Havel)/Brandenburg/Germany