Of course, right now we all know better, and according to Matthew Savoca, lead author of the research paper in Science Advances, seabirds need a good sense of smell above all else because they get their food from the ocean and other large expanses. Seabirds feed on krill, and it is evident to them that there is prey around when they smell the chemical, so they eat the krill and the plastic the algae are floating on.
Sea birds are making the mistake of eating plastic waste because its smell reminds them of food, a study has found.
The researchers also warned fish also could be eating floating plastic for the same reason, and it could have severe consequences not only for fish but also for humans who eat them.
Birds derive no energy from consuming plastic, unlike, say, actual food, so the animals are expending both time and energy attempting to consume and digest it, and filling their bellies with wasted content. "Yet, based on their foraging strategy, this study shows they're actually consuming a lot of plastic and are particularly vulnerable to marine debris".
"Plastic might not only be visually confusing for these birds, but chemically confusing", Savoca said. But it turns out, tube-nosed seabirds such as kiwis, albatross and petrels use their keen sense of smell to hunt for food. This is a big concern for scientists, who are still investigating the possible consequences for the marine ecosystem - but until now, researchers weren't completely sure why so many animals were mistaking the plastic for food in the first place.
It had been suggested that perhaps the plastic simply looked like food to marine animals (as it's not just birds nibbling on the trash).
To learn exactly what marine plastic debris smells like, the scientists put beads made of the three most common types of plastic debris-high-density polyethylene, low-density polyethylene, and poly-propylene-into the ocean at Monterey Bay and Bodega Bay, off the California coast.
Roughly 10 million tons of plastic is dumped into the ocean every year, 90 percent of seabirds gulping it up. On the contrary, they did not detect any DMS when they tested plastic that hadn't been soaked in the sea. This discovery could explain why seabirds like albatrosses and petrels swallow plastic items, often causing them injuries and deaths.
They retrieved them three weeks later and had them analyzed at the university's Department of Viticulture and Enology, facilities typically reserved for analyzing wine flavor chemistry. They are also among the birds most severely affected by plastic ingestion.
"These species nest in underground burrows, which are hard to study, so they are often overlooked", she said.
In this study, the scientists used plastic beads of the type used in bottles, bags, textiles and hundreds of applications, ranging from 4 to 6 millimetres in diameter.