I wonder if there is a fear of backlash to it. Edinburgh and Bristol reportedly wanted them in their late 00s masterplan, same for the never to be realised Biota. There is no reason we couldn't keep them as well as they do on the continent. One day, perhaps..To be fair, there’s probably one or two UK collections that could do a manatee exhibit very well.
It’s a shame manatee aren’t more widely represented