I think the current thing is quite likely an organic uprising. Things have been very very broken in Venezuela for a while now and the people there aren’t happy. Lots of people have been fleeing to Colombia for a while now and there are solid signs the election results were made up.
They’re little sea puppies that are perfectly happy to cruise around while you swim with them. At least that’s the grey nurse sharks we get in aus. The ones you’re describing sound more like wobbegongs or similar. The grey nurses need to be in highly oxygenated water.
Grey nurses also used to have a rep as “man eaters” but that was just because of how they looked,not any actual attacks