Plasticosis: How Ocean Plastic is Damaging Seabirds' Health

Marine life, including seabirds, is especially at risk from plastic waste. They confuse the floating plastic waste in the ocean for food. Researchers recently came up with the name "plasticosis," which refers to a condition where consuming plastic fragments causes the digestive tracts of seabirds to become damaged. The same researchers and their colleagues have now shown that sable shearwater chicks exhibit abnormalities in their stomach lining, renal and liver problems, and symptoms of dementia-like brain impairment (1^✔ ✔Trusted Source
Seabirds in crisis: Plastic ingestion induces proteomic signatures of multiorgan failure and neurodegeneration

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How Plastic is Affecting the Endangered Seabirds

These seabirds, which are distributed in the Pacific and Indian Oceans, were once known as flesh-footed shearwaters. The International Union for Conservation of Nature has classified them as "near threatened." The use of plastic by adults is one factor thought to be responsible for their reduction.

According to Jack Rivers-Auty, a lecturer at the University of Tasmania and a co-author of the study, "It was absolutely shocking to see these signals of dementia because these birds are less than 100 days old and they live up to 37 years. And we are discussing a median of one and a half teaspoons of plastic in these birds' stomachs."

In order to find illness indicators in the blood of these birds that consume plastic, Rivers-Auty and his colleagues employed a proteomics approach based on mass spectrometry. They found 31 shearwater chicks on Lord Howe Island in Australia in 2023 that were similar in terms of weight and the length of their wings and beaks. According to Rivers-Auty, "these birds looked healthy in every way." However, the contents of their stomachs showed that some birds had consumed less plastic, while others had comparatively large amounts of visible plastic.

The amounts of 202 out of 745 plasma proteins discovered in the birds' blood varied significantly between the two groups, the researchers observed. For instance, the researchers discovered elevated amounts of intracellular proteins such as lactate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase in shearwaters with higher plastic content. According to Rivers-Auty, this discovery implied that "all these proteins that should have been inside of cells were now outside" and that "the plastic was inducing cells to pop."

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How Plastic is Leading to Brain, Liver and Kidney Problems in Seabirds

Additionally, his researchers discovered that the blood of birds with more plastic in their stomachs had lower levels of albumin, a protein produced by the liver. Low levels could be a sign of renal or liver problems. A molecule known as brain-derived neurotrophic factor (BDNF), which is essential for the development, survival, and operation of neurons and influences memory and learning, was also markedly reduced in these birds.

While fishing off the coast of Japan, juvenile birds must "mentalize where their island is, where their burrow is, and remember it for five years before they have to return on that exact [approximately 10,000 km] journey," according to Rivers-Auty. "They may forget." According to the study, a decrease in BDNF levels may also interfere with the birds' capacity to recognize one another's songs.

Laura Dagley, who was not involved in the work but is the head of the proteomics laboratory at Australia's Walter and Eliza Hall Institute of Medical Research, calls it concerning. "However, the suspected consequences are something that really need to be monitored and measured," said Walter.

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Plastic Exposure in Seabirds

Whether these shearwater chicks are still impacted as adults is unknown at this time. However, in order to evaluate the impact of plastic exposure, the researchers are examining the blood of other adult sable shearwaters in the same colony.

However, the finding presents the shearwaters as “sentinel species,” alerting us to new environmental and health risks, according to Shane Burgess, a veterinarian and proteomics scientist at the University of Arizona who was not involved in the study.

In order to determine whether the results are consistent, he and Dagley hope that future research would include comparable work on other bird species that are similarly impacted by plastic pollution.

Reference:

1. Seabirds in crisis: Plastic ingestion induces proteomic signatures of multiorgan failure and neurodegeneration - (https://www.science.org/doi/10.1126/sciadv.ads0834)

Source-Medindia