On Friday, 5000 sturgeon were introduced into the Narva River and scientists hope the extinct population will now recover.
In the past, Atlantic sturgeon was widespread in rivers flowing into the Baltic Sea, but now, the species is extinct because of human activity, Aktuaalne kaamera reported.
To restore the sturgeon population, an international working group has been set up which includes Estonian scientists.
In the summer, 10,000 sturgeon were brought from Germany to Estonia, which grew into young fish. Half of them were released into the Narva River on Friday.
"At the moment they are going a little downstream and they are looking for suitable places because they come from Põlula fish farm, where they have had their own growing conditions. Now they have to cope in nature," said Meelis Tambets, a researcher at the Estonian Nature Conservation Center.
"The plan is to continue to populate for many years. We introduce the fish for a while, and when the first ones start to spawn, the need for our repopulation will disappear and the sturgeon population will recover. That is our goal, "he added.
Editor: Helen Wright