Seabird chicks that ingest even small amounts of plastic are suffering from hidden but severe health issues, including cell damage, organ failure, and cognitive decline, new research from the University of Tasmania has found.
The study, published in Science Advances, analysed changes in 745 proteins found in young seabirds with and without plastics in their stomachs. Researchers focused on young (less than 90 days old) sable shearwaters (Ardenna carneipes) that appeared outwardly healthy.
“Plastic ingestion research is often documented on severely emaciated wildlife showing clear signs of malnutrition,” explains Alix de Jersey, lead author and PhD candidate from the University of Tasmania’s School of Medicine. “However, we wanted to understand the burden of living with plastic in the stomach.”
The team used proteomics, the study of proteins and their regulation, to assess the birds’ health. While proteomics is commonly applied in medical research, it’s rarely used in wildlife studies.
By analysing blood samples from seabird chicks with low and high levels of plastic ingestion, the researchers identified signs of damage in multiple organs, including the stomach, liver, and kidneys, as well as evidence of neurological decline.
“Previous research has found that microplastics impact filtering organs, such as the liver and kidney. However, this research expands on this by emphasising the extent to which these organs are not working as they should in an animal that appears visually healthy. If the liver and kidney are failing or beginning to shut down, this could have serious repercussions for their long-term survival”, de Jersey explains.
Caption: Alix de Jersey.
Imagine a world without plastics
One of the most striking findings was a nearly 50% decrease in a protein called brain-derived neurotrophic factor (BDNF) in chicks with plastic ingestion. “BDNF plays a crucial role in the growth and survival of neurons, which are essential for overall brain health,” she says.
The proteins examined in this study are very similar or unchanged across different groups of organisms, even those that are distantly related, meaning the effects observed in seabirds could extend to other species—including humans.
“[This study] highlights the potential for this research to be undertaken on other species, such as marine mammals, who are known to be at risk to high quantities of ingested plastic,” de Jersey says.
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