The key factor is that they want live crab. Since Japan is very close to Russia, Russian well boats dock directly in Japan to unload their catch. That is actually why Japan has turned to Russia for its supply of snow crab. The United States turned to Canada because their stock in Alaska is declining. We sell them our snow crab at high prices. So Japan has turned a bit to Russia to the detriment of our exports because it could no longer compete with the United States.
On September 26th, 2016. See this statement in context.