I think MagicJ's suggestion is best.
I would think though that your morphs are probably stuck to the rack itself and the coralline algae has grown around them.
Do you know what these morphs are? I think I have similar ones but have never been able to find out what they are called (if they have a name at all).
Also, if you like these morphs so much, this might be the time to stick the knife in and cut across the entire morph (half-way through the mouth) and then cut each half off the rack as MagicJ said. You might then end up with two morphs from each one (or maybe just one dead one). Really worth having a go at it, especially if you haven't tried this before.