Microplastics can now be found everywhere: from Antarctic to the apparently untouched mountain lake, from the atmosphere to the deep sea. And of course the remains of our civilization also find their way into the food chain. In the New Zealand Gulf of Hauraki in front of Auckland alone, whales absorb three million particles of microplastics every day. Five small plastic particles can be found per teaspoon of Walkot, shows a study by Emma Carroll from the University of Auckland and her team in "Science of the Total Environment".
Together with a provider of whale watching tours, the working group collected the faeces of Bryde and sei whales in the water and analyzed them in the laboratory. These whales belong to the baleen whales and filter plankton from the seawater. Carroll and Co then extrapolated how much food the animals ingest per feeding process and how large the amount of microplastics underneath is. With every mouth full of krill and other small animals, the whales swallow 25,000 microplastic particles.
However, most of it comes directly from the plankton: the animals themselves had already recorded the microplastics. In contrast, only every 1000th particle comes from the free water. "This clearly shows how the microplasty is accumulated in the food chain," says Carroll. Previous studies had already shown that the whales in the Golf eat practically continuously during the day and absorb around 100 times a day. In relation to the entire inventory on site, biologists come up with the order of size of microplastics in the millions. Only part of it is excreted again. So far, what health consequences this has for the marine mammals is still unclear.
