The fallout from Russia's invasion of Ukraine more than a year ago continues to roil the global seafood supply chain.

But the issue has taken on new urgency in the United States. An acrimonious rift -- spurred by the introduction of a bill by Dan Sullivan and Lisa Murkowski, US senators from Alaska -- has developed between whitefish processing giants on the east and west coasts of the United States.

Sullivan, together with Murkowski, introduced the bill in June -- a slightly revised version of the same bill put forward just after Vladimir Putin's invasion of Ukraine -- calling for a ban not only on direct Russian seafood imports but also products sourced in Russia and reprocessed elsewhere.