The Hawaiian Islands are magnets for plastic debris from around the Pacific Basin. Plastic accumulates on our shorelines, where it’s eaten by fish, birds, and other wildlife.
Nicole Mejia is a graduate student at Cornell University and Scott Edwards is the chair of the Department of Organismic and Evolutionary Biology at Harvard University. With help from the Maui Nui Seabird Recovery Project, they recently published a study looking at the effects of plastic in Maui’s ‘ua’u kani, also known as the wedge-tailed shearwater.
Almost half of the 28 birds they looked at had plastic in their stomachs. Mejia said catching the birds took a couple of trials.
"We would go out at sunset when the birds were coming back from feeding, and then they would sit outside of their burrows and socialize, and then we'd sneak up behind and try to capture them using our hands," she said.
After being caught, the birds were then taken to get their stomachs pumped to see if they contained any plastic. Mejia said they discussed whether the amount of plastic found was large enough to cause a physiological response.
"I think one interesting thing is that a lot of the other studies that have looked at plastic presence have looked at birds that have been deceased for a while, and so you do a dissection or look at the corpse, whereas we're doing more of the stomach pump and looking at more of one part of the stomach and the contents in that part, rather than getting a full picture," she said.
Edwards said that the amount of plastic Mejia found was less than what one might see in the media.
"You've seen these pictures of dead sea birds, literally their stomach just bursting with plastic. And in this particular study, that wasn't the case. As the abstract says, we were really looking at these sub-lethal effects, whether we know the birds are compromised at some level, but we're not sure how visible that is at the level of blood chemistry or genes," Edwards said.
He said that to their knowledge, this study is a first of its kind. The study ended up not finding a significant relationship between the presence of plastic and the body's condition as measured by the blood chemistry of Maui's wedge-tailed shearwaters. However, Edwards hopes that the study doesn't signify that plastics are unharmful to birds.
"Hopefully our study inspires people to look in more detail at these complex questions. I would love to follow up this study looking at larger numbers of birds and maybe even different populations, because I was actually born in Hawaiʻi, and I have a very, very soft spot in my heart for the islands," he said.
To view the study, click here.
This interview aired on The Conversation on Dec. 18, 2024. The Conversation airs weekdays at 11 a.m. on HPR-1.
