New diver here, so please excuse if this is a stupid question. We were taught not to touch whale sharks, because it damages the protective mucus coating on their skin. Is there a similar concern for seals? I've just always been taught to be reticent around any sort of wildlife, because often when they become too habituated to humans, it does not end well for the critters. But I do not know if this is true in all situations.
I've never heard of a protective mucus coating on the skin of a whale shark ... but I think there are a lot of good reasons not to attempt to handle them, just as would be true with other wild animals. That said, there are right and wrong ways to interact with these creatures, and if you don't know the right way it's best not to do it at all.
Generally speaking, divers should interact with marine life in its terms ... many creatures, seals especially, will initiate contact and interaction. If you "allow" the animal to interact, I see nothing wrong with it. They always have a choice to leave. If you force contact, you not only run the risk of stressing the animal, they may also mistake your intent as aggression, and act accordingly ... and that can lead to injury to either you or the animal. If, during interaction, a critter appears to want to escape, give it an escape route and let it go ... that's a clue that your interaction isn't wanted, and could lead to a bad outcome. If, on the other hand, the creature is initiating contact, then I don't see a problem with "playing".
As far as seals go, they are protected by the Marine Mammal Act, and there are some concerns whenever interacting with them that you may be in violation of the law in that regard (at least, in the USA).
... Bob (Grateful Diver)