Tentacled sea creatures are taking over the Earth’s oceans

Octopuses and their tentacled brethren are taking over the seas, as ocean temperatures climb and humans snaffle up their natural predators.

Zoe Doubleday, a marine biologist at the University of Adelaide in Australia, and her colleagues were studying an iconic local species, the giant Australian cuttlefish, which had been in decline for several years.

Doubleday wanted to see whether it was part of a larger cyclical trend in global populations, so she looked at data from surveys and from cephalopod fisheries and cephalopod bycatch in finfish fisheries between 1953 and 2013.

To her surprise she found a consistent increase in cephalopod populations over the past six decades, in species from all over the world and in every habitat, from the deep ocean to the near-shore shallows. Read more in New Scientist.