An American explorer descended nearly 11 km into the Pacific Ocean and found plastic waste in the Mariana Trench, the deepest place on earth. Victor Vescovo, a retired naval officer and investor, said he conducted an expedition inside his submersible that went 35,853 feet or 10,928 meters into the trench, Reuters reported.

The area in the ocean is known as Challenger Deep. The dive is part of an initiative to explore the deepest points in each of the world’s five oceans.

Vescovo said he hoped his discovery would increase awareness of dumping of waste into the oceans and push governments to incorporate measures to counter such practices. “It was very disappointing to see obvious human contamination of the deepest point in the ocean,” Vescovo said. “It’s not a big garbage collection pool, even though it’s treated as such.”

Vescovo, who funded the expedition, said his team found four new species of prawn-like crustaceans called amphipods, and saw a spoon worm and a pink snailfish, BBC reported.

Experts will test the samples collected by Vescovo for the presence of micro plastics.

His expedition was the third of its kind, following the first made by a United States Navy official in 1960 and another by Canadian filmmaker James Cameron in 2012.