Answer:
They focused more on farming.
I'm sorry if this isn't right but from what I learned it's the first one :)
<span>Russian Sturgeon is a ancient species of fish which is about 4 meters long. The fish is a rare one with bones in it and weighs about 160 kg. They usually found near Bulgaria, Russia and Turkey. The population the Russian sturgeon further declined because of the construction of dams on the Volga</span>