NOAA Begins Mission to Remove Marine Debris from the Northwestern Hawaiian Islands
A diver frees a Hawaiian monk seal from a derelict net.
A diver frees a Hawaiian monk seal from a derelict net.

SEPTEMBER 28, 2014 - Roughly 140 miles north of the main Hawaiian Islands, an archipelago of remote, tiny islands and atolls rises out of the sea. They stretch northwest for another 1,500 miles and are part of the Papahānaumokuākea Marine National Monument, a UNESCO World Heritage site and one of the largest marine conservation areas in the world.

These Northwestern Hawaiian Islands, in addition to being a sacred cultural site for Native Hawaiians, give shelter to more than 7,000 marine species, including endangered Hawaiian monk seals, 14 million seabirds, rare and threatened land birds, and green sea turtles. They encompass 5,178 square miles of the healthiest and least disturbed coral reef habitat in U.S. waters.

They are also virtually pristine, save for the estimated 52 tons of derelict fishing gear that wash up there from sources around the Pacific Ocean, unabated, every year.

On September 25, a team of 17 scientists and trained divers from NOAA’s Pacific Islands Fisheries Science Center (PIFSC) and two of the Marine Debris Program’s own staff embarked on a 33-day mission to remove derelict fishing nets and plastics from the sensitive reefs, shallow waters, and shorelines of the Monument. The crew is making its way there aboard the NOAA Ship Oscar Elton Sette and will remove debris from five areas: Maro Reef, Laysan Island, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll.

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“Marine debris is an on-going threat to the Monument’s natural resources,” said Mark Manuel, chief scientist for the mission. “It’s critical that we get up there and remove this debris so we can mitigate any coral damage and prevent entanglements.”

Derelict fishing nets continue to catch marine life for years after they are lost and are a constant entanglement threat for the monk seals, green sea turtles, seabirds, and other wildlife that depend on the vast coral reef ecosystem. The reefs themselves are in danger from abrasion and scouring as the heavy nets glide through the currents and snag on vibrant corals, in some cases coming to rest on top of the reef structure.

The team will disembark from the Sette at each location and work in teams from small boats, conducting in-water surveys and pulling nets weighing hundreds of pounds from the corals and seafloor. It is no easy task, and the divers undergo extensive training and rigorous physical assessments to become part of the mission.

At islands and atolls where there is some land, such as Midway Atoll and Laysan Island, the team will also do shoreline cleanups and surveys. PIFSC, in cooperation with the Marine Debris Program, started a shoreline debris accumulation rate study at Midway in 2012.

The nets go in a large, dumpster-sized container aboard the main ship, where they await transport back to Honolulu; from there, they will become electricity to power homes as part of Hawaii’s Nets to Energy partnership with Covanta Energy and Schnitzer Steel.

This mission is critical to keeping marine debris from building up in the Monument. Because there is no way yet to prevent nets and other debris from entering the shallow waters, removal is still the best solution. It also yields big results. Last year, the team hauled 14 metric tons of fishing gear from shallow-water reefs of Midway Atoll alone.

In 2014, two Marine Debris Program staffers participated in NOAA's annual mission to remove derelict nets and other marine debris from sensitive coral reefs and shorelines in Papahānaumokuākea Marine National Monument, one of the largest marine conservation areas in the world. An estimated 52 tons of derelict fishing gear washes up in the Monument each year, threatening the pristine ecosystem. Follow their journey.