THE number of jellyfish spotted around the coastline has risen significantly this year, prompting scientists to call for more research into whether it indicates a warning about the state of our seas.

The massive barrel jellyfish have appeared in record numbers for a second consecutive year while the lion's mane has been reported in Scotland in great numbers, with about 100 to 150 per sighting, particularly around the Ayrshire coast.

Moon jellyfish have also been seen in good numbers in the likes of Strontian at the head of Loch Sunart on the west coast and at Rosehearty in Aberdeenshire. The blue and compass species are also in Scottish seas.

Figures compiled by the Marine Conservation Society show there were over 1,400 reports of jellyfish last year.

By July this year, its survey had already received more than 1,000 reports. August is usually a peak month for jellyfish sightings and so 2015 looks set to be another record breaker.

Dr Peter Richardson, MCS's Biodiversity and Fisheries Programme Manager, said: “We know that our seas are changing through climate change, resulting in rising sea temperatures and increased ocean acidification, and we know our seas are also heavily fished.

"At the same time we seem to be witnessing increases in jellyfish around the UK. Is this an anomaly, a coincidence, or are the jellyfish telling us something about fundamental changes in the condition of our seas?”

"Smacks" of barrel jellyfish normally make up 10 per cent of MCS's annual reports, but last year they made up 40 per cent. Now so far in 2015, 75 per cent of records have involved barrel jellyfish sightings.

They are no strangers to Scottish waters having been frequently observed in and around the Firth of Clyde and also the Irish Sea over the years.

But they appear to have be been moving south. They have been reported throughout the year all around the UK, but most 2015 reports from south and south west England.

Barrel can weigh up to 4st 10lb and measure more than three feet across. Unlike other species they are thought to be able to survive the winter on the seabed and reappear early the following year.

Meanwhile, in July huge numbers of mauve stingers were reported off Guernsey, and the potentially dangerous Portuguese Man O War has been washing up on beaches in the south west of England.

MCS said that more dedicated research and monitoring is needed to understand these apparent increases and what they mean for the state of our seas.

“Our National Jellyfish Survey suggests significant recent rises in the numbers of some jellyfish species in UK seas, most notably the barrel," Dr Richardson said. "The million-dollar question is why is this happening? At the moment we just don’t know."

The MCS Jellyfish Survey started in 2003 and involved thousands amongst the sea and beach-going public reporting their jellyfish encounters online at the MCS website.

Mr Richardson said huge ‘smacks’ of jellyfish were not a new phenomenon, with jellyfish blooms having been found in the fossil record over 500 million years.

Nowadays they can have important economic and social consequences.

Moon jellyfish blooms have forced the closure of UK nuclear power stations, leading to the industry investing in remote sensing mechanisms to detect increases in jellyfish near power plants.

In the UK large blooms of mauve stinger jellyfish have wiped out salmon stocks in fish farms, while the same species regularly closes down bathing beaches in the Mediterranean due the animal’s painful sting.

“People are fascinated by jellyfish and that’s why our survey is one of our most successful citizen-science projects.

"But we believe there is now a need for UK Government to commission dedicated scientific research and monitoring to answer pressing questions about what is happening to jellyfish numbers, why it is happening and what this means for our precious and productive seas,” Mr Richardson said.