Freshwater eels have a remarkable life cycle, which begins and ends in the ocean. Spawning has never been observed but there are good indications that the European eel uses the Sargasso Sea as their spawning ground.
The larvae of European eels travel with the Gulf Stream across the ocean and, after one to three years, their leptocephali reach a size of 75 ? 90 mm before they reach the coasts of Europe. The common name for this recruitment stage of eels is glass eel, based on the transparency of the body. they recruit to coastal areas they migrate up rivers and streams, overcoming all sorts of natural challenges ? sometimes by piling up their bodies by the tens of thousands to climb over obstacles ? and they reach even the smallest of creeks.
In freshwater they develop pigmentation, turn into elvers (young eels) and feed on creatures like small crustaceans, worms and insects. They grow up in 10 or 14 years to a length of 60 to 80 cm. In this stage they are now called yellow eels because of their golden pigmentation.
By the time they leave the continent their gut dissolves making feeding impossible, so they have to rely on stored energy alone. The external features undergo other dramatic changes as well: the eyes start to enlarge in size, the eye pigments change for optimal vision in dim blue clear ocean light, and the sides of their bodies turn silvery, to create a countershading pattern to make them difficult to see by predators during their long open ocean migration. These migrating eels are typically called "Silver Eels" or "Big Eyes".
Because the eels are catadromous (living in fresh water but spawning in the sea), dams and other river obstructions can block their ability to reach inland feeding grounds. Since the 1970s an increasing number of eel ladders have been constructed in North America and Europe to help the fish bypass obstructions. This concern has been behind COUNCIL REGULATION (EC) No 1100/2007 of 18 September 2007 establishing measures for the recovery of the stock of European eel.
Despite a significant hydrological system and numerous hydro power plants existing and others on drawing phase, Albania has not recognized this issue as part of environmental concerns to be taken into account the EIA required for granting the building permits of new and refurbished power plants.
This project will focus in Buna river ? Drini River ? Ohrid Lake hydrologic system. The system is shared by two countries Albania and Macedonia and both countries have aspirations for joining the European Union. The natural migration of eels from the Adriatic Sea to the Ohrid Lake has been interrupted in many places by the construction of hydroelectric dams.
The project will consist in capturing young eels entering the Buna river and transporting them alive in oxygenated tanks to the Ohrid Lake where they will be released. Eventually, the project will provide for the transportation of the adult eels captured on the Macedonian side and their release on the Buna river.