Getting together for a grand hootenanny, or massing for war?
As I have said many times, humanity's dominance of the world's islands and coastlines will last only as long as it take octopi to start working together, or for dolphins to figure out you can use kelp to choke their hominid aggressors.
(I suspect those elbow squid are going to be involved somehow, too. They already look like regular squid inside mechanised war-suits. The fact they're staking out deep-water oil-wells is surely no coincidence. Can't construct undersea armoured divisions without precious dinosaur juice!)