Baltic sturgeon, Acipenser oxyrinchus, is an anadromous species that reproduces in fresh water and spends most of its life at sea. The species is long-lived (up to 100 years) and grows large (up to 4.5 m total length and 350kg in weight) but also reproduces late, at an age of 12-18 years. As such, sturgeons are extremely vulnerable to overfishing. Baltic sturgeon in the 19th century was still widespread, although it reproduced only in the rivers entering the southern part of the Baltic Sea and lake Ladoga.
Unfortunately, populations declined within the last century. Reasons for such decline were unsustainable harvest, waterbourne pollution, and hydro-constructions (both damming and for navigation purposes) resulting is excessive loss of habitat for reproduction and early life stages. The last wild sturgeon catches were observed in 1968 in the Vistula, 1970 in Odra River, 1984 in Lake Ladoga and 1996 in Estonian waters near Saaremaa Island, where the last specimen was caught.
It took several years to realize that Baltic populations of sturgeons did not belong to Acipenser sturio, as previously though, but rather to the Atlantic American sturgeon, Acipenser oxyrinchus, the true Baltic Sturgeon. But, by that time, the species was already exctinct.