70 Years On, Seabirds Continue to Warn about Plastic Pollution in the Oceans
Plight of the flesh-footed shearwater in Australia illustrates how widespread the problem is
A special report ahead of World Oceans Day
It’s a late May night on Lord Howe Island, and the moon gleams across the volcanic mountains and white sand beaches of this six-mile long isle off the east coast of Australia. While most people are tucked inside their houses or hotels, conservation biologist Dr. Jennifer Lavers and her colleague, naturalist Ian Hutton, don headlamps and bike to the flesh-footed shearwater colony on the northeast side of the island. Lord Howe Island is one of the two main breeding areas for this seabird in the southwest Pacific Ocean (the other is in northern New Zealand). Tonight the colony bustles with 90-day-old chicks flapping their wings as they prepare for their first 6,500-mile flight north to the Bering Sea.
Lavers and Hutton set up a makeshift research station in the colony, and handpick chicks to weigh, measure, and take feather samples. They also undertake a lavage process, guiding a tube down each bird’s throat to flush out its stomach contents. This part may seem gruesome, but the lavage provides important information about shearwater diet and nutrition. If a fledgling’s parents fed it well, it will regurgitate natural food sources like squid and fish. But more often than not, chicks will cough up something that does not belong in their stomachs – plastic.
Seabirds ingesting plastic debris that they mistake for food isn’t exactly breaking news. Scientists first discovered plastic debris in the Laysan Albatross in the 1960s. By the mid-1990s, over 111 seabird species were reported to have plastic in their stomachs, pointing to an escalating problem of plastic pollution in our oceans. “Seventy years on, these birds are still saying the same thing,” Lavers says. “They’re telling us that ocean condition is deteriorating, and we need to act now to improve manufacturing processes and management.”
Even though many seabirds are affected by plastic pollution, the flesh-footed shearwater illustrates how widespread the problem is. The species has been listed as “near threatened” in Australia and “nationally vulnerable” in New Zealand.
For years, scientists believed the majority of plastic congregated in the North Pacific gyre, commonly known as the “Great Pacific Garbage Patch.” However, there are actually five main gyres that circulate plastic across the oceans. “A large percentage of the plastic that arrives on Lord Howe Island comes from Australia and New Zealand,” Hutton reports, “But plastic also comes from the Northern Hemisphere. We pick up a lot with Asian writing.”
Both shearwater adults and fledglings ingest plastic, but Lavers and Hutton surmise that adults have the instinct to cough it up. However, when the parents forage for their chicks plastic is inadvertently served for supper. “Fledglings sit in their burrows for about 90 days, getting fed food and plastic,” Hutton explains. “They tend not to cough up in the burrow, so the chicks retain that plastic for the entire 90 days.”
Plastic can puncture a chick’s stomach, leading to ulcerations, infection, and death. Lavers and Hutton also recently discovered that shearwaters are suffering from significant heavy metal contamination, most likely because of their plastic-rich diet. Plastic leaches toxic chemicals like chromium and cadmium into a bird’s bloodstream, causing permanent physiological and neurological damage. “Having just one piece of plastic in a seabird can potentially be detrimental,” Lavers says. “There is no safe threshold.”
Lavers studies seabirds around the world, but some of her most shocking finds have been with flesh-footed shearwaters. She once dissected a shearwater chick that contained 276 pieces of plastic, which was 14 percent of the bird’s body weight. While this case was extreme, the quantity of plastic found in shearwaters has increased nearly every year. In 2011, Lavers and Hutton found plastic in 96 percent of the flesh-footed shearwaters they studied. In 2012, 100 percent of the chicks contained plastic.
Despite this linear trend, 2014 is proving to be an anomalous year. The chicks seem to have less plastic inside them, but more pumice. As Lavers explains, the increase in pumice is probably due to the Kermadec Volcano eruption in 2012, which littered the Tasman Sea with volcanic rock. “It’s sad to say that plastic is the norm now,” Lavers says, “but I have to say that plastic is the norm. And yet we’re seeing a significant reduction in the proportion of birds containing plastic, and also the total number of pieces in each individual bird has gone down.” While this development could be viewed as a positive shift for the species, Lavers notes that most of the shearwater chicks were severely underweight this year, which points to a larger problem.
“It’s important to do studies over many years,” Hutton explains. “If someone had come in this year, and said, ‘okay, let’s see how the birds are being impacted by plastic,’ they might not think it’s a problem.” Lavers and Hutton have yet to publish their latest findings, but their next paper will examine the patterns and trends in flesh-footed shearwaters over the past 15 years, which could provide valuable information about ocean health. (Long-term studies like the one Lavers and Hutton are conducting are rare and underfunded. They rely on private donors, crowd-funding, and spend a lot of personal money to fund their research)
In the meantime, we need to listen more carefully to what flesh-footed shearwaters – and other seabird sentinels – are telling us. Hutton stresses the importance of public education, and the need for governments to work with corporations to reduce plastic waste. Lavers also believes that plastic pollution needs to be struck at the roots, placing responsibility with the industries that produce it. “Ocean plastic is the modern day Trojan horse, little toxic bullets in sheep’s clothing,” she says, “Exposing the enemy is a monumental task, but we may solve the problem if we find a way to prevent plastic from reaching the ocean in the first place.”
Help fund Lavers and Hutton’s research by donating here.