Biologists left baffled after Pacific jellyfish invade Scottish coast

Published on Friday 11 September 2009 20:51

IT IS a tiny and almost transparent jellyfish, barely 5in in diameter, and completely harmless of humans.

But the unprecedented discovery of the crystal jellyfish in the waters of the Moray Firth – an ocean away from its normal habitat off the Californian coast – has shocked wildlife watchers.

They have been left puzzling whether the jellyfish arrived in Scottish waters as a result of global warming, changes in tides and currents, or simply as a result of being transported across the Atlantic in the bilges of a boat.

Specimens of the crystal jellyfish (Aequorea victoria) have gone on display at the aquarium in the Aberdeenshire town of Macduff after their discovery by Ian Page, who runs wildlife-watch trips at sea from his Banff-based business, North 58.

He spotted a small number of the tiny jellyfish in a bay between the Local Hero village of Pennan and the nearby hamlet of New Aberdour. He said: "It was a type of jellyfish I had never seen before. I was shocked when I discovered they were crystal jellyfish, usually found in deep water in the Pacific between California and the Bering Sea."

The Marine Conservation Society, which runs an annual jellyfish watch around Britain's shores, confirmed it was the first report of crystal jellyfish off the coast of Scotland.

Mr Page said: "I have now seen about 100 of these jellyfish, but I have only found them in one bay along the entire coast. They are really close inshore – within 15ft of the rocks.

"I haven't a clue how they got here. I don't know if it's down to global warming. On the other hand, they could easily have come in a ship's ballast, which has been pumped into the waters of the firth."

Peter Richardson, the Marine Conservation Society's biodiversity programme manager, confirmed it was the first-ever report in Scottish waters.

And he revealed the discovery of the tiny jellyfish in the Moray Firth was just one of a series of unusual incidents jellyfish around our coast in recent weeks.

A week ago, the society received a report of a mass stranding of a stinging jellyfish, called the mauve stinger, at Reef Beach on Lewis in the Outer Hebrides.

And, over the past six weeks, the MCS has received an unprecedented number of reports of strandings of the Portuguese man-of-war on beaches on the Isle of Wight, Devon and Cornwall, Wales and the Isle of Man.

Mr Richardson said: "It has been an interesting year for jellyfish all round the coast.

"The reasons are not yet clear," he said, "although persistent south-westerly winds will have played their part."