By Chris Ciaccia
Published May 20, 2019
Plastic pollution and climate change may be significantly altering the level of oxygen on our planet. Now, a new study dives into the impact it could have on marine life, including squids, crabs and octopuses – blindness.
The study, published in the Journal of Experimental Biology, highlights how important oxygen is to sight and retinal activity for certain marine larvae. Tiny declines in oxygen levels result in significant vision impairment, including almost total blindness in certain species.
"Using in vivo electroretinogram recordings, we show that there is a decrease in retinal sensitivity to light in marine invertebrates when exposed to reduced oxygen availability," the study's abstract reads. "We found a 60-100 [percent] reduction in retinal responses in the larvae of cephalopods and crustaceans: the market squid (Doryteuthis opalescens), two-spot octopus (Octopus bimaculatus), tuna crab (Pleuroncodes planipes), and brachyuran crab (Metacarcinus gracilis)."
To test the theory, the animals were put in reduced oxygen environments for approximately 30 minutes.
The research highlights that it is likely there is a change in oxygen in the daily environment of these animals due to swimming at different depths, but it underscores the concern that a permanent decline could be destructive.
"These findings may impact our understanding of species’ vulnerability to ocean oxygen loss and suggest that researchers conducting electrophysiology experiments should monitor oxygen levels, as even small changes in oxygen may affect the results," the study's abstract adds.
"I am concerned that climate change is going to make this issue worse," the study's lead author, Lillian McCormick, said in an interview with Live Science. She added "that visual impairment might happen more frequently in the sea."
Luckily, the vision impairment was not permanent, as vision functionality returned in a typical environment. McCormick and her team found that all of the larvae were able to get 60 percent of their vision back and some eventually returned to full strength.