In a place as remote as Papahanaumokuakea Marine National Monument, which remains uninhabited by humans, one imagines pristine shores and clear, turquoise waters.

Yet a team of 18 divers who returned two weeks ago from a trek to the chain of isles and atolls located 1,200 miles northwest of the main Hawaiian islands, hauled out some 164,917 pounds of fishing nets and plastic waste. That’s more than 82 tons, comparable to the weight of 45 mid-sized cars or one space shuttle, according to the National Oceanic and Atmospheric Administration, which runs the expeditions.

The haul from the Northwestern Hawaiian Islands at Papahanaumokuakea includes more than 51,000 pounds of derelict fishing nets removed from the shallow water coral reefs at Pearl and Hermes Atoll, more than 63,000 pounds of nets and plastics from Midway Atoll, and more than 50,000 pounds of nets and plastics from Kure Atoll, Pearl and Hermes Atoll, Lisianski Island, Laysan Island and the French Frigate Shoals.

“Pretty much anything you can imagine that’s made by humans, that’s made of plastic and floats, we have found it in the Northwestern Hawaiian Islands,” said NOAA’s Kevin O’Brien, who served as chief scientist for the mission this year.

The list is all-encompassing: motorcycle helmets, car bumpers, traffic cones, toilet seats, umbrellas, bowling balls, plastic pink flamingos, printer ink cartridges, mannequin heads, shoes, boots, toothbrushes, plastic drinking bottles, plastic utensils and cigarette lighters.

The team of divers from NOAA Fisheries and University of Hawaii’s Joint Institute of Marine and Atmos­pheric Research embarked on their trip Sept. 19 and returned Oct. 29.

Despite Hurricane Walaka, they managed to carry out Marine Debris Removal Mission 2018, setting off from Honolulu for Pearl and Hermes Atoll, then Midway Atoll and a sweep from Kure Atoll to Lisianski and Laysan islands and the French Frigate Shoals.

At NOAA’s Ford Island headquarters on Friday, the team had sorted out the debris into categories such as plastic laundry baskets, fishing nets, tires, buoys and smaller personal-care items like plastic toothbrushes and combs.

On the ground was an art piece created out of the trash, a blue and green Earth in the center, surrounded by the words “Marine Debris Everyone’s Problem.”

It’s a paradox that the world’s most isolated archipelago, where no one lives, ends up with so much human-generated litter, O’Brien said. Due to its central location in the system of circulating currents called the North Pacific Gyre, the debris has been carried by currents to its shores for decades.

NOAA’s marine debris team has been going on expeditions to the Northwestern Hawaiian Islands almost yearly to survey and remove litter since 1996. Cumulatively, including the last mission, teams have collected about 2 million pounds of debris.

The litter does ecological damage at Papahanaumo­kuakea, O’Brien said. Derelict fishing nets routinely break and smother live coral reefs and pose an entanglement danger to wildlife. Since 1982, there have been 366 documented cases of Hawaiian monk seals caught in the nets, which is a rate of about 10 per year.

“When you’re talking about only 1,400 individuals left in the species, these numbers matter,” he said.

Plastic pieces, when broken down, are ingested by numerous species of sea birds, turtle and fish.

O’Brien said the team found two green sea turtles with fishing nets tangled around their necks and flippers and were able to free them at Pearl and Hermes Atoll.

“So you can imagine for every entangled animal that we find, there are undoubtedly numerous other ones that we don’t,” he said.

The most numerous items collected from shorelines are plastic pieces broken down from larger items, followed by fishing floats, buoys, plastic beverage bottles, cigarette lighters and personal-­care items such as toothbrushes. Much of this can come from inland sources, he said, not just from litter off seagoing boats.

The work is difficult and labor-intensive, and the debris is scattered across vast areas, some of which are inaccessible due to surf, reef structure or shallow water. O’Brien said the debris collected represents hours of free diving without scuba gear, hiking along shorelines, carrying heavy loads and stooping over to pick up small pieces of plastic.

For the first time on a mission, drones were used to locate nets in shallow-water coral reefs. Photomosaic technology also is being employed to stitch together individual underwater images to create 3-D maps that document scars left behind on coral reefs by the nets. The team also attached satellite tags to six nets to study their trajectories over time.

Becca Weible, a UH graduate student in zoology, recalled the hours she and others took trying to extricate a fishing net from a reef about 15 feet deep at Pearl and Hermes Atoll. The nets were thick and heavy, she said, and lifting them onto a boat was the most difficult part.

For her, it was disheartening to see floats and buoys wash up within a matter of days after cleaning a shoreline.

“It just felt like a never-­ending process,” she said.

The fishing nets will be sent to Honolulu’s HPOWER waste-to-power plant through the Hawaii Nets to Energy Program, while some of the plastics will be repurposed and recycled for educational purposes, including an exhibit at the Maui Ocean Center.

O’Brien said part of the mission is to share what’s going on at Papa­hanaumokuakea with the world.

“So ultimately this issue of marine debris in our most wild, sacred places reflects on us as stewards of our natural world, and I think we could do better, and I know we can,” he said. “At the end of the day, a cleanup is just a cleanup. But unless we do something to stem the tide of plastics into the ocean, we’re not really going to solve this problem.”