Even though most octopuses don’t live long, as a group they’re doing very well. Available data show that over the last sixty years octopuses and other cephalopods have increased in abundance worldwide.
Cephalopods are rapidly adapting to our changing world, helped perhaps by their swift life cycles. Warming seas, driven by climate change, could cause them to grow and reproduce even faster, giving them an edge over their competitors. Changes in habitats and ocean currents, and an increase in extreme weather events could shift the balance in favour of cephalopods.
The loss of other species may also play a part. When fish populations crash from overfishing, cephalopod numbers often shoot up. Around Elephant Island near Antarctica, icefish numbers collapsed in the 1980s. Since then, icefish haven’t returned but octopus numbers are much higher than in nearby areas. It’s possible octopuses are doing well because they’re no longer being hunted by icefish.
Time will tell how octopuses will fare in the future. It’s likely that fisheries will increasingly target abundant cephalopods, so they too could spiral into decline.
Some octopuses seem safe from human activities – though perhaps only for now. In 2016, scientists found ghostly white octopuses beyond the reach of fisheries, 4,000 metres down in the Pacific. Dubbed ‘Casper’, these octopuses lay eggs on sponges growing on potato-sized rocks that take millions of years to form. These rocks are rich in precious metals and may soon be dragged up from the deep to make electric-car batteries, solar panels and smartphones. If deep-sea mining goes ahead, Casper could lose her nursery bed.