 In April 2019, following the discovery of a dead sperm whale off of Sardinia with 48 pounds of plastic in its stomach, the World Wildlife Foundation warned that plastic pollution is one of the most dangerous threats to sea life, noting that five whales have been killed by plastic over a two-year period.Some of the tiniest bits of plastic are being consumed by small fish, in a part of the pelagic zone in the ocean called the "Mesopelagic zone", which is 200 to 1000 metres below the ocean surface, and completely dark.Not much is known about these fish, other than that there are many of them.