SHETLAND's buoyant economy is "already heavily reliant" on the many hundreds of EU nationals who have made the isles their home and are employed in various occupations.
But in order to keep functioning the islands will have to attract many more Europeans, according to Shetland Islands Council's development director Neil Grant.
Like many other rural places, Shetland is suffering from a serious demographic imbalance that threatens the islands' viability.
With an ageing population and no additional inward migration, jobs in the health and care sectors, in fish processing, tourism and many others industries are likely to remain unfilled.
In order to rebalance the impact of that ageing population, Shetland needs to attract, or retain, as many as 1,400 working age people by 2028, Grant said, and many will have to come from the continent.
In the past inward migration was mainly from Scotland and the rest of the UK, but over recent years young people from EU member states have made up the majority of "soothmoothers".
With Brexit looming, Shetland could therefore be seriously affected should EU nationals be restricted or even prevented from moving to the UK.
"The most obvious place to look at is Scotland and the rest of the UK," Grant said. "But the reality is that Shetland relies very heavily on Europe; estimates suggest that there are around 1,000 people from Europe in Shetland."
Population projections estimate that the number of those aged 65 and over will increase from 18.7 per cent of the local population in 2015 to almost 25 per cent in 2028.
The same projections also suggest that for Shetland to achieve the same proportion of 16 to 40 year olds than the rest of Scotland (30.4 per cent) it needs to attract an additional 1,380 people.
The figures for the Western Isles and for Orkney are even more pronounced.
Isles MP Alistair Carmichael stood up in the House of Commons on Monday to urge the UK government to give a unilateral guarantee to those EU nationals already living in this country.
On Tuesday, speaking to Shetland News, he went one step further by saying that, without continuous inwards migration, island communities were in danger of becoming unsustainable.
"Population levels are absolutely critical to maintaining businesses and economic growth in island communities, and we need people from outside Britain to keep growing and sustaining our communities," Carmichael said.
"That is why for Theresa May threatening a hard Brexit, walking away from our export markets in the single market and also closing down the flow of migrant workers from other parts of the EU for us would be double whammy."
He acknowledged that the local predicament did run contrary to government immigration policy.
"Once we lose the EU immigration we will be one of the first to feel the pinch, because the jobs that will be attractive and easy to get will be the jobs in the big cities and the towns, and we will struggle to get people to come to settle and work in the islands," he said.
The SIC has confirmed that it is planning to use the Our Islands Our Future (OIOF) mechanism to lobby the UK Government, and Carmichael added that he was ready to make the islands' case.