Man-made pollution has been plaguing our planet’s oceans for decades now. As a result, it is common to find marine animals’ stomachs filled with plastic. For instance, a recent study found that 99% of seabirds will have ingested plastic debris by 2050. Another study found that every single of the 50 marine mammals that washed ashore in Britain had ingested plastic at some point in their lifetime.
|Credits: Deep Ocean Facts|
Turtles are among those that usually ingest plastics. Some experts argue that these animals tend to mistaken plastic materials with food. But, a recent study provided a deeper explanation for this. According to All That’s Interesting, a site for curious people who want to know more about what they see on the news or read in history books, the study occurred over two weeks in January 2019 and involved 15 loggerheads. The turtles were placed in tanks that were exposed to a variety of smells at the surface, which included the neutral one of water, food such as shrimp, and new plastic as well as ocean-soaked plastic.
|Credits: European Scientist|
The findings of the study published in Current Biology showed that sea turtles may be confusing plastic for food. Ocean-soaked plastics emit a chemical gas called dimethyl sulfide -- a gas also produced by phytoplankton, which is a food source for many marine animals. This shows that ocean plastic dupes these animals because of their attractive scent. UNC-Chapel Hill biologist Kenneth J. Lohmann stated that the findings are important because it’s the first demonstration that the odor of ocean plastics causes animals to eat them.
|Credits: All That's Interesting|
Dr. Joseph Pfaller explained that plastic bags, netting, and bottles have essentially been serving as dangerous “olfactory traps” for these animals. “Plastics that have spent time in the ocean develop smells that turtles are attracted to and this is an evolutionary adaptation for finding food, but it has now become a problem for turtles because they’re attracted to the smells from the plastics,” Pfaller said.