According to a study from Stanford University, blue whales consume about 10 million pieces of microplastics every day. The researchers discovered that blue whales eat the most microplastics because they only consume krill, a shrimplike animal. Matthew Savoca, the study co-author, elaborated on the findings in a statement. “The krill eat the plastic, and then the whale eats the krill,” Savoca explained.
The study found that blue whales consume the most microplastics. This is because they typically swim 50 to 250 meters below the surface of the ocean. This is where concentrations of microplastic are highest. The research also examined humpback and fin whales. They found that they consume a smaller amount of microplastics because the food in their diet is different.
The study found that all the microplastics that the whales ingest come from their prey, not the enormous amounts of seawater they intake when trying to catch their food. Humpback whales eat primarily fish and therefore ingest about 200,000 pieces of microplastics per day, while fin whales eat krill and fish which leads to them ingesting 3 to 10 million pieces of microplastics each day. Even though these results aren’t concrete, they still make researchers question if whales are getting the essential nutrients for their survival.
More research is needed to examine the diet of blue whales
Shirel Kahane-Rapport, the lead study author and a Ph.D. student at Stanford speculated on this in a statement. “We need more research to understand whether krill that consume microplastics grow less oil-rich and whether fish may be less meaty, less fatty, all due to having eaten microplastics that gives them the idea that they’re full,” Kahane-Rapport explained.
The new results are an essential first step in understanding the potential chemical and physiological effects of microplastics on filter-feeding animals like whales. The next steps involve studying how oceanographic conditions produce dense areas of both microplastics and prey. It will also examine how microplastics reduce the nutritional value of key prey species for whales.
To find how much microplastics each whale intakes, researchers for this study measured the microplastic concentration along the California coast. They then looked at 2010 to 2019 tracking data from worldwide whales to see where they look for food.
Governor Gavin Newsom has single-handedly lowered the ocean’s microplastic levels. He signed a bill in July to reduce shampoo and laundry detergent packaging use in California. The bill reduces the dependence on single-use products by 10% in the next few years. It will be reduced by 25% over the next decade. Amy Wolfrum, senior ocean policy manager at the Monterey Bay Aquarium in California, told the Associated Press that though the bill was just a start, it addressed a significant problem well.