The river Crni Drim got its name thanks to the silicate, endemic algae with a black color. You can spot them at the bottom of the water as they tremble carried away in their underwater dance. In the waters of Crn Drim there is a variety of fish species, such as carp, chub, eel, barbel and others. The Ohrid eel for millennia migrated from Lake Ohrid to the Sargassian Sea for reproduction. In the second half of the 20th century, with the construction of the two dams on the Macedonian part of the river Crn Drim, and four on the Albanian part, the eel route was completely blocked. Dams are a problem for other fish species that used to travel to the Ohrid Lake from the Adriatic Sea. According to the IUCN World Red List, European eel is considered a critically endangered species.