Over 2.5 million juvenile eels were released into the Kaliningrad and Curonian Lagoons in the Kaliningrad Region to help preserve the endangered European river eel population. The release is part of efforts to artificially reproduce fish in the region, as the species faces declining numbers due to over-fishing and the construction of dams. The first batch of glassy eel larvae was brought from Great Britain in 2022, and subsequent releases have seen the number of juvenile eels released into the Kaliningrad (Vistula) Lagoon rise from 430 thousand in 2022 to 1,163 thousand in 2023.