How do sea birds eat crustaceans

Why seabirds like plastic

Around eight million tons of plastic end up in the world's oceans every year. Last but not least, seabirds that eat the plastic suffer from this. US researchers have now found out why they are doing this.

Plastic in the ocean smells similar to some types of plant-based plankton - tiny little algae; they give off the smell of dimethyl sulfide (DMS) - you can imagine it like cooked vegetables or cooked seafood.

For seabirds such as albatrosses, tube noses or shearwaters, DMS means: food scent! Because their food is crustaceans and small fish: These eat plankton and therefore live exactly where a lot of plankton thrives. If plastic swims in salt water for a long time, the same algae form - including the smell, as a study by a team led by the biologist Gabrielle Nevitte from the University of California, Davis has shown. This is devastating because birds find it difficult or impossible to digest plastic, and in the worst case they perish.

J.J. Harrison

Blue petrel over the sea

Hope: Use other plastic

To prove that plastic can be an odor trap for birds, the US study evaluated, among other things, the data on the stomach contents of 13,500 seabirds. Those birds that are guided by the DMS odor when searching for food are six times more likely to eat plastic than other animals.

Chemical analyzes showed that some types of plastic take less than a month to develop the odor that is attractive to seabirds. The researchers hope that if it is not possible to discharge less plastic into the oceans, then industry could at least use plastics that are not so easily overgrown by algae.

science.ORF.at/Ö1 Science

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