The central estimate for blue whales was 10 million pieces per day, meaning more than 1 billion pieces could be ingested over a three to four month feeding period. The weight of plastic consumed during the season was estimated at between 230 kg and 4 tonnes. In heavily polluted areas, or if plastic pollution continues to increase in the future, whales could be eating 150 million pieces a day, the researchers warned. The data was collected in California’s coastal waters, but scientists said other parts of the world were more polluted. The research is the first to estimate microplastic consumption for blue, fin and humpback whales, which are baleen whales and use filters to catch their prey. He found that almost all of the microplastics consumed are in the krill and fish that the whales eat, rather than in the water. Plastic particles are similar in size to the food that smaller organisms eat. Whales could be harmed by the microplastics and toxic chemicals they carry, and previous work has found plastic-derived contaminants have been detected in their blubber. The mammals are still recovering from the whaling trade and face other anthropogenic impacts such as noise and ship strikes. “What we found was surprising – really high numbers of daily plastic ingestion,” said Dr. Shirel Kahane-Rapport, at California State University, Fullerton, who led the study. “We imagine it will have some kind of impact, but we don’t know the exact health effects. This is the first step to understanding it.” There are many more polluted ocean basins in the world than off the coast of California, Kahane-Rapport said, including the North Sea, the Mediterranean and waters off Southeast Asia. “Whales that feed in these areas may certainly be at greater risk than on the coasts here in the western US,” said Dr. Matthew Savoka, of Stanford University, who was part of the team that conducted the study. “It’s a sad story for the whales, but it’s also a story for us,” Savoca said, as human diets are also affected. “Whether it’s cod or salmon or other fish, they eat the same fish that bowhead whales eat. Huge amounts of plastic waste are dumped into the environment, and microplastics have polluted the entire planet, from the top of Mount Everest to the deepest oceans. At least 1,500 wild species have been reported to ingest plastic. Humans ingest the tiny particles through food and water as well as through inhalation. Microplastics were revealed to be present in human blood in March. The research, published in the journal Nature Communications, combines a series of measurements to estimate the whales’ consumption of microplastics. Tags on 191 blue, fin and humpback whales recorded more than 36,000 feeding shots from the whales, and airborne drones were used to measure how much water was taken in each stroke. The most important stories on the planet. Get all the week’s environmental news – the good, the bad and the must-haves Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. Prey density in water was assessed using acoustic devices and microplastics in prey were estimated using previous research and measurements of plastic pollution in the water column. The scientists found the whales feeding mainly at depths of 50-250 meters, where most microplastics are found. Humpback whales, which are smaller than blue whales, have been estimated to ingest up to 4 meters of microplastics per day when feeding on krill and 200,000 particles when feeding on fish such as anchovies. The researchers believe their estimates are conservative, as plastic pollution will have increased since the data were collected, and made conservative estimates of how much plastic krill and fish prey consume.
