European eel

The life cycle of the European eel is complex and spans several distinct developmental stages. All European eels are believed to hatch from eggs in the Sargasso Sea in the western Atlantic Ocean. The larvae, known as leptocephali, drift on ocean currents toward the coasts of Europe and North Africa, a journey that can take one to two years. Upon reaching coastal waters, they transform into glass eels, then elvers as they enter river systems. They spend the majority of their lives—often 5 to 20 years—as yellow eels in freshwater, brackish, or coastal habitats before maturing into silver eels and migrating back to the ocean to spawn once and die. The species has experienced a dramatic reduction in numbers. While estimates vary, some sources suggest that the number of eels reaching European waters has declined by approximately 90 percent, with some estimates reaching as high as 98 percent, since the 1970s. This decline is attributed to a combination of human-driven pressures, including overfishing at various life stages, the construction of barriers such as hydroelectric dams that impede migration, habitat loss, and pollution. Additional threats to the species include the spread of parasites, such as Anguillicola crassus, and potential changes in oceanic currents. Illegal, unreported, and unregulated fishing, as well as the illegal export of eels, remain significant concerns. In response to these threats, the European eel was listed in Appendix II of the Convention on International Trade in Endangered Species (CITES) in 2007. Since 2010, the European Union has prohibited the import and export of the species to and from its member states. Management efforts are ongoing across Europe, involving the development of national eel management plans, the installation of fish passes, the removal of obsolete dams, and stricter fishing regulations. Despite these measures, the status of the European eel remains critical, with recruitment levels for glass and yellow eels continuing to be very low compared to historical averages.