More than a third of creatures died in a year at a sealife attraction owned by one of Britain’s biggest leisure companies.

Some 35.4 per cent of marine animals – including sharks, rays and jellyfish – were lost at Great Yarmouth Sea Life Centre in Norfolk.

A similar proportion died at the Scarborough Sea Life centre, although an ‘error’ was later blamed for inflating that figure by around a third.

Attraction: A stringray at the Sea Life Centre in London

The chain’s Manchester centre reported a 15 per cent mortality rate and Blackpool 7 per cent.

Experts said mortality should be less than 10 per cent, even when taking into account species with short lifespans, and called for an inquiry. The Marine Conservation Society also announced it was reconsidering its sponsorship deal with Sea Life over the ‘particularly disturbing’ death rates.

The chain is owned by Merlin Entertainments, which includes Legoland Resorts, Madame Tussauds and Alton Towers.

The company blamed the figures at Great Yarmouth on the ‘naturally high mortality of jellyfish’ and fluctuations in a large tank’s filtration system which had been ‘very difficult to diagnose’.

It also said different aquariums could not be compared ‘like for like’ because of the range of animals they contain.

But biologist and TV presenter Dr Ben Garrod, an ambassador for the MCS who was born in Great Yarmouth, said he was shocked.

‘You wouldn’t go into a hospital and expect a one-in-three chance of dying. You wouldn’t expect that in a zoo. I don’t think it is acceptable,’ he said.

The Captive Animals’ Protection Society demanded an investigation into welfare standards and called for aquariums to be shut down.

There are 12 Sea Life Centres in Britain. Information was supplied by Great Yarmouth and Hunstanton in Norfolk, as well as London, Manchester, Scarborough, Weymouth, Birmingham and Blackpool following Freedom of Information requests by the BBC. Brighton failed to provide figures.

Aquariums with 20m visitors Sea Life is the world’s largest aquarium brand, with more than 20million people visiting 50 aquariums and six sanctuaries The organisation has 180,000 marine animals in its care Around 3.5million people visit the 12 Sea Life Centres in Britain each year Attractions include tunnels through giant aquariums and short submarine rides in other tanks The largest centre in Germany, in Oberhausen, was home to Paul the ‘psychic octopus’, which correctly predicted the national football team’s results at the World Cup in 2010 Other countries with centres include the US, Belgium, France, Spain, Australia and Thailand The aquarium chain promotes conservation, rescue and campaigning work under its SOS – Save Our Seas – scheme Advertisement

They showed a total of 4,500 creatures died between 2015-2016 at the centres which responded. Some 812 of these occurred at Great Yarmouth, out of a total of 2,293 marine animals. A letter from an inspector appointed by the Department for Environment, Food and Rural Affairs warned managers there that the data it supplied, including mortality rates, could be ‘analysed in a manner that may be detrimental to the company’.

Another 965 were declared at Scarborough, although this was later reduced to 590 after the centre said there had been a ‘formatting error’.

The chain lost 13 sharks or rays and two undulate rays, which appear on the ‘red’ endangered list of the International Union for Conservation of Nature.

Great Yarmouth had the highest death rate among these species, at 21 per cent, according to an MCS analysis – ‘almost double’ the level at other centres. The society said the discrepancies in Great Yarmouth ‘need to be examined and explained’.

It said it had been reassured ‘to some degree’ by Sea Life’s explanation of ‘unforeseen problems’ but was still reviewing the sponsorship it received from Sea Life for its Pocket Good Fish Guide.

A Sea Life spokesman said: ‘Sea Life places the very highest priority on the welfare of the animals at its sites, which are supported by experienced animal care teams, marine biologists and world-renowned veterinary consultants. Sea Life has a strong track record in animal husbandry and complies with all the laws and regulations under the Zoo Licensing Act.’