To be fair to Merlin, they only purchased Changfeng ocean world recently (2012, according to wiki). Sealife has been campaigning against keeping various species in captivity for a while. Didn't they used to have a campaign against keeping sand tigers and then they bought up London Aquarium! This story just seems a opportunity for the press to have a dig at Merlin. The running of the park seems to be seperate to the Sealife chain so I don't see how its a double standard.
The Daily Mail does have a bit of an anti animal keeping slant at times, though they still like to show cuddly baby zoo animals. So they also can do double standards too
Unfortunately the Daily Mail is now working with Caps, where Caps send their biased campaigns to the daily mail to print. Hence all the anti zoo stuff recently! I haven't read the article yet but caps recently relased a campaign called Sealies all about Merlin and the anti cetacean attitude but keeping cetaceans.
If you actively read the daily mail, I have a message for you: Don't. In regards to the sand tigers, I remember picking up a leaflet in the early naughties saying 'we are against the keeping of whales, dolphins and certain species of shark, like sand tigers.' Does anybody get the hint that London's zoological facilities do not do the wonderful city justice?
Whether you read the daily mail or not, it doesn't take away from the fact that caps are working closely with them on campaigns. And as we know, Anything giving caps a higher platform (wether tabloid newspaper or not!) is bad news for zoos and animals in captivity in general.