A section of farmland in Easter Ross has been flooded in a bid to create a salt marsh barrier against the force of the tides.
The RSPB bought land to flood
The move by the Royal Society for the Protection of Birds (RSPB) is the first project of its kind in Scotland.
The organisation has breached the sea wall next to land it owns in Easter Ross.
It believes that flooding could be the way to deal with rising sea levels in other areas.
Scientists are predicting that global warming could mean the sea level on the east coast of Scotland rising by 23 centimetres within 50 years.
That would destroy low-lying land trapped between flood defences and the sea.
These habitats cannot move, and so they are being eroded away
An RSPB spokeswoman said: "In a natural situation, these mudflats and salt marsh would migrate inland as the sea levels rise.
"But around a lot of the firths we have these hard coastal defences which are protecting agricultural land or industry or housing.
"These habitats cannot move, and so they are being eroded away."
The RSPB is also concerned about the fate of thousands of birds which depend on the mudflats for food and shelter. "There is nowhere else for them to go," she added.
The organisation has bought farmland at Nigg, on the Cromarty Firth, and in the past two weeks has broken through the sea wall to allow the salt marsh to move inland.
It said letting nature take its course could be more effective in future than spending huge sums of money building new walls.
Banks on either side of the flooded field - which was reclaimed from the sea 50 years ago - will prevent the water from spreading to neighbouring land.
Local people were initially concerned about the deliberate flooding but are now said to be coming round to the idea.