Scottish fishermen have warned of serious implications for the industry after Russia banned all imports of fish, meat and other foods from the EU.
President Vladimir Putin's order suggested a return to Russian consumer isolation not seen since the days of the Soviet Union.
Other industry bodies, including the Scottish Whisky Association, said they were concerned their products could be hit next.
The ban was ordered in retaliation against EU and US sanctions, designed to stop Russia-backed arms being funnelled into Ukraine.
But Putin's administration ordered tougher-than-expected clampdowns, leading to warnings they would hurt Russian consumers.
The move affects all 28 countries that make up the European Union, as well as the United States, Canada, Australia and Norway. The ban covers all meat, fish, poultry, dairy, fruit and vegetables, meaning Scottish salmon, mackerel, beef and even haggis are now off the menu in Russia. Alcohol is currently excluded, alongside tea, coffee, sugar and grains.
The sanctions, which began yesterday, are due to last for a year.
Scotland's exports to Russia are worth about £200 million a year, including £25m of whisky. Russia has also threatened to ban EU and US airlines from flying across its territories, a move that could significantly increase the duration and the cost of many flights.
Last month Downing Street warned UK businesses to prepare themselves for "pain" as the EU and US announced sanctions on doing business with Russia. At that stage the Prime Minister David Cameron warned the crackdown might not go far enough and might have to be extended.
Bertie Armstrong, the chief executive of the Scottish Fishermen's Federation, warned: "We are at this stage extremely concerned about the impact they will have on our mackerel fleet."
A Scottish Government spokeswoman said the action would "inevitably have an impact on some sectors of our economy, most notably for our fish exporters".