Whales near the city of Auckland, New Zealand, consume around 3 million microplastics per day. A team of international researchers, including Associate Professor Thijs Bosker of Leiden University College in The Hague and Ph.D. Laura Zantis, a student at Leiden University, concluded after examining whale droppings.
This is the first time that microplastic pollution has been examined by examining whale droppings instead of water samples. “Essentially, whales are constantly taking samples of their environment and prey when feeding,” Zantis said on the Leiden University website. “We wanted to understand by looking at their poop how many microplastics they consume each day and whether those microplastics are in the food of whales or in the water they ingest while feeding.”
Researchers have found that whales in the Hauraki Gulf, near Auckland, feed primarily on small plankton like krill. By calculating the amount of prey consumed per bite of krill, the researchers estimated that whales consume around 25,000 microplastics each time they capture prey. Most come from the prey. Only 1 in 1,000 comes from water. Microplastics come from a variety of human-made products, such as plastic bottles, cigarette filters, and clothing.
One of the big questions that must be answered now, Bosker says, is whether whales absorb these microplastics and what that means for them. “Are these microplastics having any negative effects on the body? Three million is a lot, but we have to determine how harmful it is.”
