Byline: Sally Williams
AN EXTENDED period of calm, warm weather has brought an abundance of wildlife into Welsh coastal waters.
Rare leatherback turtles, basking sharks, large groups of jellyfish and superpods of dolphins have all been spotted in Welsh seas in the past few weeks.
The impressive array of marine life around Wales is due to a hot spell in the early part of the summer, along with tranquil conditions, which have made the Irish Sea a perfect bathing area for a variety of species.
Leatherback turtles, the world's largest sea turtles, have already been spotted this summer off the coast of Pembrokeshire, near Barmouth in Gwynedd, and also off Ceredigion and Conwy.
According to the Marine Conservation Society, it has also been a bumper year for basking sharks, which are routinely found in Pembrokeshire waters.
And earlier this month a 1,500-strong super pod of dolphins and their young, stretching for a mile were spotted off the Pembrokeshire coast.
Peter Richardson, MCS biodiversity programme manager, said the long, hot summer, combined with three weeks of calm coastal waters, have provided excellent conditions for the rich diversity of marine species to feed and thrive.
"As seas continue to warm up during the summer, more jellyfish blooms are expected, which in turn will attract more leatherbacks," he said.
"After three quiet and wet summers, the Welsh coast is now very productive.
"It is a bumper year for jellyfish in the Irish Sea, particularly the large and robust barrel jellyfish and wind sailors, that occur inshore infrequently but were seen in huge numbers in South-West Wales in May.
"This means that the rare leatherbacks have been in luck.
"Wildlife watchers have been in luck too, because the leatherbacks have been spotted in-shore.
"In Conwy, a lady was sitting on her balcony 10 days ago when she spotted one just 10 metres off shore.
"She had thought it was a big, black upturned boat until she saw it poke its head out of the water.
"She noted that it had been feeding on blue and compass jellyfish. And we are keen to find other turtle hotspots in Wales."
The MCS Jellyfish Survey which is being launched today, aims to uncover the little-known habits of Welsh jellyfish, as part of a wider programme to find out more about leatherback turtles that migrate thousands of miles to Welsh waters.
By mapping where and when the jellyfish are seen, MCS hopes to understand more about leatherback turtles.
"This year's jellyfish season started in April in the Irish Sea, when barrel and large blooms of moon jellyfish were reported off Anglesey," said Mr Richardson.
"Through May and June, reports increased, with moon jellyfish elsewhere along with other species, such as the beautiful blue and compass jellyfishes.
"We started receiving reports of stranded lion's mane jellyfish off Wales in June.
"Lion's mane and some other species can sting, so we are encouraging holidaymakers to look, don't touch."
He said the largest ever leatherback turtle was found off the coast of Harlech in 1988. "Sadly it drowned after being caught up in fishermen's ropes to a whelk trap and a post-mortem revealed that its gut was full of plastic.
"Turtles can mistake plastic bags and buoys for jellyfish and the plastic fills their gut until they can starve to death. Out of 400 that have been washed up dead on our beaches, 34% had plastic in their gut.
"But fishermen are more aware of this now, so they add lead weights to their lobster and crab pot ropes.
"However at sea, tens of thousands of leatherbacks get caught up in longline nets catching tuna and swordfish."
He said the jellyfish survey is an excellent way for people to get involved in finding out more about marine life.
"Around the world jellyfish numbers are increasing, especially in our temperate seas, and scientists have linked these increases to factors such as pollution, over-fishing and possibly climate change," said Mr Richardson. …