The birds on this tiny, remote island are so full of plastic their bellies crunch

CNN

23-05-2025

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On a remote, crescent-shaped island surrounded by crystal-clear ocean live some of the most plastic-contaminated birds in the world. They have bellies so full of fragments, they crunch when touched.
Lord Howe Island — a speck of land about 370 miles off mainland Australia, home to just a few hundred people — is the breeding ground for tens of thousands of sable shearwaters: dark brown-colored, long-winged ocean birds with strong hooked bills.
Scientists from the ocean research group Adrift Lab have been visiting for nearly two decades to monitor these birds' exposure to plastic pollution. Every year they find more contamination, but this year was shocking, said Jennifer Lavers, a marine biologist and coordinator of Adrift Lab, who recently returned from the island.
Shearwaters were found with levels of plastic far exceeding anything the scientists had seen before. They discovered an extraordinary 778 pieces of plastic inside one chick alone, smashing the previous record of 403 pieces.
It 'left us all speechless,' Lavers said. The scientists are now trying to solve the mystery of why this year was so bad. Plastic pollution is on the rise but 'does that explain a doubling in 12 months? Absolutely not,' she told CNN. 'So there's something else going on.'
Seabirds are often referred to as sentinels for ocean health, and the story they're telling is alarming.
Global populations have declined 70% over the last 50 years as they grapple with multiple threats, including from invasive species, the fishing industry and climate change.
Plastic pollution is yet another danger and a particularly 'insidious' one as its impacts are so hard to detect, said Richard Phillips, a seabird ecologist at the British Antarctic Survey.
Lord Howe Island offers a unique natural laboratory for studying seabirds.
The shearwaters reliably come back to the same breeding colony each year, usually within inches of the same burrow, allowing scientists to track individual birds' progress. 'There's nowhere else in the world that I can think of where we could do a study like this,' Lavers said.
The scientists visit every April and May, when the chicks are leaving their burrows for the first time and preparing to take their first big migration to the Sea of Japan.
Shearwaters are nocturnal, so every dawn, the scientists go to the beach to find chicks that were too weak and emaciated to make the flight. They bring them back to the lab to examine them. 'We often see high levels of plastic in these birds,' said Alix de Jersey, a researcher at the University of Tasmania.
The scientists return to the beach at night to analyze the healthier birds getting ready to fly. They 'lavage' them using a feeding tube, gently pumping water into their stomachs to make them vomit up the plastic.
The process may not be pleasant, de Jersey said, but 'it's just fantastic knowing that that bird is starting its migration without this huge load of plastic within its stomach.'
Most of the plastic found in the birds this year was made up of unidentifiable fragments but they also found bottle caps, tile dividers and large amounts of plastic cutlery, de Jersey told CNN.
The plastic accumulates inside the birds' bodies and can form a kind of brick. The pollution is so crammed into some shearwaters, it's audible. 'You can hear the crunching of the bottle caps and the shards and things shifting and moving against each other,' Lavers said.
Listen to plastic crunching inside birds
Sable shearwater birds on Australia's Lord Howe Island are so full of plastic their bellies make an audible crunching sound when scientists touch them.
Source: Dr Jennifer Lavers/Adrift Lab The scientists believe most plastic is ingested due to parents accidentally feeding it to their chicks, instead of the fish and squid that make up their usual diet.
Plastic may smell good to birds because of the algae that can coat it, said Matthew Savoca, a marine ecologist at the California Marine Sanctuary Foundation and Stanford University. 'Other times, birds may eat something that has already eaten plastic,' he told CNN.
Shearwaters are particularly vulnerable because, while some birds will regularly throw up what they cannot digest, shearwaters 'only tend to regurgitate when feeding their chicks. The structure of their gut also means that plastic items are retained for a long time,' said Bethany Clark, senior seabird science officer at the conservation group BirdLife International.
Scientists are still trying to unpick the health impacts; many are largely invisible.
The Adrift Lab scientists take blood samples and dissect the dead birds. This year, as soon as they opened up the shearwaters, it was obvious there were 'systemic issues,' de Jersey said. She found scarring on the birds' kidneys and hearts.
Plastic can block birds' intestines or cause starvation, but there are also 'sub-lethal' effects, Lavers said. 'They don't kill the animal instantly, but they do cause it to have a shorter life span (and) lots of pain and suffering.'
Big pieces of plastic can dig into the birds' stomachs, causing excessive amounts of scar tissue. Microplastics might pass through the birds but leave a trail of toxic chemicals.
The Adrift Lab team have even found eating plastic can cause 'dementia-like' brain damage in shearwater chicks.
Over the last decade, the team has seen a very consistent decline in the birds' body mass, wing length and other measures. Lavers used to consistently find chicks too heavy for her 1 kilogram scales (2.2 pounds), but now the very heaviest top out at about 800 grams (1.8 pounds).
What's happening to the birds on Lord Howe Island is 'truly troubling,' said Kimberly Warner, senior scientist at Oceana, an ocean conservation organization.
Global plastic pollution is only getting worse, especially as cheap, single-use plastics — the vast majority made from planet-heating fossil fuels — continue to flood the market.
An estimated 33 billion pounds of plastic waste enter the oceans each year, roughly equivalent to two garbage trucks-full dumped in every minute, according to Oceana. It takes centuries to break down.
Horrifying images of dead albatrosses with clusters of colorful plastic spilling from their bodies, turtles eating plastic bags and whales entangled in plastic fishing nets are testament to how this pollution is affecting marine life.
'It's a crisis, and it's rapidly worsening,' said Lavers, who is still reeling from what they found on Lord Howe Island this year. 'I don't have words. I don't know how to explain what it is that I'm seeing.'