Ever since Blue Planet 2 shocked us with upsetting footage of a grief-stricken whale mother dragging her dead calf, we have been obsessed with plastic. Or, rather, a desire to get rid of it.

But it’s not just the fishing gear, single-use bags, and plastic garbage we have to worry about. Microplastics are tiny particles of plastic material that find their way into the food chain and into animals' guts. They are harmful – at times, potentially lethal – and they appear to be everywhere we look. In the Arctic, in the Galapagos, and on our plates. Even, it seems, in the world’s deepest ocean trenches.

A study published in Royal Society Open Science reports examples of microplastics in animals living in the Mariana Trench, whose 11-kilometer (7-mile) depth makes it the deepest point in the world’s oceans.

“Half of me was expecting to find something but that is huge,” Alan Jamieson, from Newcastle University's School of Natural and Environmental Sciences, said in a statement.

Jamieson and his team studied 90 deep-dwelling shrimp for microplastic contamination from six ocean trenches around the Pacific Rim. These are marine beasties that live at depths of 6,000 to 11,000 meters (19,600-36,000 feet) below the water's surface. But they still can't escape the plastic crisis.

A worrying 72 percent of the shrimp tested contained at least one plastic microparticle. Some contained as many as eight. All trenches were affected, though the exact frequency of ingestion varied between 50 (New Hebrides Trench) and 100 percent (Mariana Trench) depending on the site. It is also unclear exactly how the plastic particles were ingested. Had they been ingested directly or were they from fish living at higher depths who had died and sunk?

Jamieson and the team analyzed the microplastics and found most to be from clothes fabrics like nylon. They also discovered that the particles' atomic bonds had shifted and looked different from what you'd expect to find in brand new material, meaning they were likely several years old. Jamieson suspects they had originally been dumped into the ocean via a sewage system or a river. They had started to break down and gather bacteria, which made them heavier and caused them to sink.

"We are piling all our crap into the place we know least about," Jamieson said, adding that it is hard to know how exactly it was affecting the creatures it contaminated.

"These particles could just pass straight through the animal, but in the animals we looked at they must be blocking them," he continued.

"The equivalent would be for you to swallow a 2-meter polypropylene rope and expect that not to have an adverse effect on your health... There's no good aspect to this."

With more than 300 million tons of plastics being produced each year and plastic in the oceans predicted to outweigh fish by 2050, we can only expect it to get worse.

"The salient point is that they are consistently found in animals all around the Pacific at extraordinary depths so let's not waste time," pleads Jamieson. "It's everywhere."