Crews with a Hawaii-based nonprofit reported pulling nearly 100,000 pounds of derelict fishing nets and plastic from fragile reefs and shorelines during their latest trip to rid the Papahanaumokuakea Marine National Monument of marine debris.

Most of that debris – some 86,000 pounds – was snagging and smothering the reef at Kamokuokamohoaliʻi, according to Kevin O’Brien, founder and president of the Papahanaumokuakea Marine Debris Project.

The mostly submerged reef site some 800 miles northwest of Honolulu supports endangered Hawaiian monk seals, green sea turtles and other diverse marine life, according to a PMDP release.

The group recently returned from its 27-day trip to the monument aboard the ship M/V Imua, the release stated. Crews also removed some 11,000 pounds of debris from shorelines at Laysan and Lisianski islands. They plan to return to the monument later this month for another cleanup operation.

The nonprofit has been traveling to the monument since 2020 and typically removes between 80,000 and 120,000 pounds of debris over several weeks, mostly from remote reef sites such as Kamokuokamohoaliʻi, O’Brien said.

About 115,000 pounds of additional debris accumulate each year at Papahanaumokuakea, according to PMDP Executive Director James Morioka.

O’Brien said the group aims to conduct at least two large-scale operations each year. Its goal is to offset the new debris tonnage plus chip away at the backlog of marine debris from years prior.

Crews typically use inflatable boats to carefully navigate tight spaces in the shallows and delicately remove the nets and debris without further damaging the reefs, he said.

“It’s like a maze,” O’Brien said.

The cleanup trips are funded through a collaboration with the National Oceanic and Atmospheric Administration and other federal agencies, according to the release.