Dominant Species

Captain Beck is an astronaut who has a unique problem. Why? Because the hero has just witnessed, while completing his 160th orbit around the planet Earth, ten spaceships entering into the Earth's atmosphere, and into the Earth's oceans. Captain Beck have to alert NASA about what he had seen, but with his career on the line, and with him holding out, he notices strange phenomenons occurring around the world. People dying without putting up a fight, and their heads are the only thing that was left. Their bodies have been devoured. The sea creatures of the oceans have all been eaten, and their heads were all floating on top of the water.
The sea was a graveyard, with the smell of death that hit the shores. The president of the New World Council has given instructions for the presidents around the world to drop hundreds of nuclear bombs underwater together, to kill off the aliens, who call themselves Argolians, but that was mankind's biggest mistake. The oceans began to boil. The polar caps started to melt. Giant tsunamis were forming around the world. The water started rising. Buildings were being swallowed up. The landmass was dwindling. The aliens came above the water to feed on mankind. Will mankind continue being the dominant species, or will there be a new dominant species on the planet Earth?