Swathes full of drifting plastic bits are especially common in a region of the Pacific Ocean southwest of California that is sometimes called the Great Pacific Garbage Patch.
However, the ocean currents that cause the Pacific gyre don’t just happen in the North Pacific.
In a new study, Professor Bruce Mate from the Hatfield Marine Science Center in Oregon working with Jorge Urban of the Autonomous University of Baja California Sur, placed data-recording tags on sperm whales feeding on Humboldt squid in the Gulf of California.
The tags use GPS and depth sensors to track the whales' movements in three dimensions for up to 28 days, then detach and float to the surface.
Scientists found that the mammal can induce the condition when there is little food around and turn it off when food is abundant.
Scientists from the US National Marine Mammal Foundation said that bottlenose dolphins are resistant to insulin - just like people with diabetes only in dolphins, this resistance is switched on and off.
They believe it is a unique ability in the animal kingdom and results from the mammal’s need to maintain high blood sugar levels to feed its big brain.