Scotland's islands and coasts are under threat from an alien invasion of millions of exotic jellyfish.
Not only are they exotic but they're killers. The mauve stinger jellyfish (or pelagia noctiluca) has been seen numerous times in the waters of the west and north in recent weeks. They're usually found in warmer areas such as the Mediterranean or Red Sea but the milder autumn this year may have encouraged them to have a swim further north.
The latest cluster or 'bloom' of the creatures was spotted off Orkney last week. Each jelly fish, which feeds on plankton, is only around 4 inches across but together they wreak havoc on fish farms and beaches and cause millions of pounds of damage.
In 2007 a bloom billions strong devastated west coast salmon farms. Worst affected was a farm in Northern Ireland where more than 100,000 fish were killed at a cost of more than £1 million.
At its worst, the solid mass covered 10 square miles of a depth of 35 feet. Jellyfish numbers are increasing all over the world. Over-fishing may mean there are fewer predators to keep numbers down.