Octopuses May Go Blind As Climate Change Sucks Oxygen Out of the Ocean

Octopuses May Go Blind As Climate Change Sucks Oxygen Out of the Ocean

  • According to a recent study in the Journal of Experimental Biology, the amount of oxygen available to marine invertebrates like squids, crabs and octopuses may be far more important to their vision than previously thought.
  • For some species, even a minuscule drop in oxygen levels resulted in almost immediate vision loss, eventually causing near-total blindness before the oxygen was cranked back up again.
  • As ocean oxygen levels continue to drop around the globe, in part due to climate change, the risks to these creatures could intensify.
  • The ocean is replete with oxygen near the surface, where air and water meet, and significantly less saturated with oxygen at 165 feet below the surface, where many crustaceans and cephalopods hide away during the day.
  • To find out whether these daily swings in oxygen affect the animals’ vision, McCormick attached small electrodes to the eyes of each one of her test larvae, none of which measured longer than 0.15 inches.
  • Within about an hour of returning to a fully saturated oxygen environment, all of the larvae regained at least 60% of their vision, with some species bouncing back to 100% functionality.
  • According to a 2017 study in the journal Nature, total ocean oxygen levels have declined by 2% globally in the last 50 years and are projected to decline by up to an additional 7% by the year 2100.