Hi Gary, it's hard to say if they're fish or not. In the last image the white scatter at the bottom of the pic was my wash as I manoeuvred the boat whilst drifting. In the first pic its possible that the brighter specks could have been small baitfish, but with sidescan you can usually tell it's a fish or not by its shape; a fish will show up as a bright, elongated shape that looks vaguely like a fish seen from above. The specks in the pic seem more circular, so it's not clear cut.
Here's an example of how fish show up on sidescan. This isn't my image (I just Googled it) and the shoal is in much shallower water, but you can clearly see the fish (tarpon) in the water column and their sonar shadows on the sea floor. I wouldn't expect this level of detail at the depth we fish over wrecks in the UK, but I would expect to see the rough shape of the fish.