Jellyfish swarms are from over-fishing
PUBLISHED: 13:54 27 July 2011 | UPDATED: 10:42 29 July 2011
A RISE in the number of jellyfish around the UK coastline is a result of over-fishing of British waters, according to an expert at Weston's SeaQuarium.
The thoughts come after The Marine Conservation Society urged beach-goers to take part in a national survey as barrel, moon, compass, blue and lion’s mane jellyfish swarm UK seas.
They believe warmer seas, pollution, over-fishing and possible climate change have contributed to the rise in jellyfish numbers.
Even in Weston, an 18-inch specimen has been found on the beach within the past two weeks. Ian Walker, of the Coronation estate, was enjoying a stroll with his family on Uphill beach two weeks ago when his son Michael spotted something which he initially thought was a plastic bag, but upon closer inspection it turned out to be a jellyfish.
Hayley Upham, displays manager at the SeaQuarium, believes the rise is due to the over-fishing of the invertebrate’s predators.
Hayley said: “There is a food chain. If you fish all the large predatory fish then you break the chain down.
“There is no large fish eating medium-sized fish and it is all because of over-fishing.
“In other countries they have had plagues of some types of rays. It could potentially be a problem for our beaches around the UK because in extreme conditions it may not be safe to swim in the sea.”
Hayley suggests consumers at supermarkets should refer to the pocket Good Fish Guide produced by the conservation society.
She said: “They should make sure they buy tuna from a sustainable source. I would encourage people to look for pole-and-line sustainably-caught tuna.”
Don Metcalfe of Worle, who has fished for 60 years across the world, has seen a change of species of fish in UK waters. He said: “There are more sub-tropical fish that in the last 10 years that have been moving in our waters.
“Jellyfish are still a rarity in the sense that you are not stepping over them.”
MCS Biodiversity programme manager Peter Richardson said: “Most jellyfish bloom in summer, but some species can survive the cool winter months too.
“This year, we received our first reports of the huge but harmless barrel jellyfish off North Wales back in early January, and this species has occurred in huge numbers in the Irish Sea and beyond ever since, with reports received from North Somerset to the Firth of Clyde.”