Everyone knows that humans are making a mess of the planet. And almost everyone knows that one of the biggest causes of the mess is plastics.

Many people may not realize, however, just how deep the mess goes (that’s a pun, get ready).

According to a new study published in the journal Marine Pollution Bulletin, Calypso Deep, which is the deepest point in the Mediterranean Sea likely has as many as 26,715 pieces of trash per square kilometer.

That’s right, this part of the ocean, which is 5122 meters (16,804 feet) below the surface is literally littered with our trash.

This is a place that no human can reach without extremely specialized equipment, and yet there are plastic ropes, cups, bags, cans, and much more all over the place.

The study was conducted by using a submarine contraption called the Limiting Factor. It went down to the bottom of Calypso Deep and analyzed the area in a relatively small section.

The device was able to identify 148 objects that are known to be trash from humans, and 19 more that are likely from humans but could not be confirmed. While most of it was from plastic, there were also glass bottles and other materials in the area.

Miquel Canals is the author of the study and also a professor at the University of Barcelona’s Faculty of Earth Sciences. He said in a statement:

“It is a closed depression, which favours the accumulation of debris inside it. The weak currents in the trench […] also facilitate the deposition of light debris at the bottom.”

This type of trash could have come from many sources including people dumping it from boats, people leaving it on the beaches and having it blow into the water, or through accidents.

Whatever the cause of the issue, the reality is that this is a major problem. Once the trash reaches these deep areas, it will likely stay there for thousands of years.

Canals continued in his statement, saying:

“The Mediterranean is an enclosed sea, surrounded by humanity, with intense maritime traffic and widespread fishing activity. The evidence provided by our research should shake up global efforts, and in particular in the Mediterranean, to mitigate waste dumping, especially plastics, in the natural environment and ultimately in the sea, in line with the UN Global Plastics Treaty against plastic pollution, which is still pending approval.”

This is an important study that will hopefully encourage at least some people to change the way they deal with their trash. Ideally, it will also help encourage governments to pass laws to discourage any type of dumping into the oceans or other bodies of water.

Canals wrapped up his statement by saying:

“The ocean floor is still largely unknown to society as a whole, which makes it difficult to raise social and political awareness about the conservation of these spaces. It is necessary to make a joint effort between scientists, communicators, journalists, the media, influencers and other people with social impact. The problem is there, and it has an enormous scope, even if it is not directly visible. We should not forget about it.”

Unfortunately, it is notoriously difficult to get people to take action on causes that they cannot directly see or touch.

Since the deepest parts of the ocean are nearly impossible to get to for the average person, this is a battle that experts will continue to have to fight.