Plastic pollution causing dementia-like signs in seabird chicks - Natural History Museum

The damage caused by plastic pollution goes far beyond the digestive system.

Beneath the skin of seemingly healthy seabirds, new research has revealed the widespread effect of plastics on crucial proteins made by the liver, kidneys and even the brain.

Looking fit is no guarantee of health for some of the world’s most plastic polluted birds.

New research, published in the journal Science Advances, suggests that the illusion of health in sable shearwaters is only skin-deep. Samples taken on Lord Howe Island, which lies between Australia and New Zealand, showed that young birds which appeared healthy were suffering from severe damage to multiple organs.

Shearwaters which had only eaten less than a gram of plastic were already suffering serious consequences. These impacts extended to the brain, where declines in a crucial protein known as brain-derived neurotrophic factor (BDNF) were similar to levels associated with conditions like Alzheimer’s disease, Parkinson’s disease and dementia in other animals.

University of Tasmania PhD student Alix de Jersey, who led the research, said that this could have severe consequences for the shearwaters if they survive to adulthood.

“Seabird colonies are an overwhelming symphony of calls, screeches and chatter that can be so loud we can barely talk to one another while collecting data,” she says. “To live in this noisy environment, sable shearwaters need to be able to distinguish between fine scale acoustic cues to locate their partner. Plastic, however, decreases levels of BDNF and interrupts the development of their song control system. This could have implications for their ability to create and maintain pair-bonds with other shearwaters.”