NOAA removes 57 tons of marine debris from Hawaiian Islands

A team of 17 National Oceanic and Atmospheric Administration (NOAA) divers recently returned froma 33-day mission to remove approximately 57 tons of debris from Papahanaumokuakea Marine National Monument in Hawaii.

Sailing aboard the NOAA ship Oscar Elton Sette, the team of divers removed approximately 57 tons of derelict fishing nets and plastic debris from the monument’s coral reefs, atolls and tiny islands.

“The amount of marine debris we find in this remote, untouched place is shocking,” said Mark Manuel, operations manager for NOAA Fisheries coral reef ecosystem division and chief scientist for the mission. “Every day, we pulled up nets weighing hundreds of pounds from the corals. We filled the dumpster on the Sette to the top with nets, and then we filled the decks. There’s a point when you can handle no more, but there’s still a lot out there.”

At Pearl and Hermes Atoll, the divers rescued three sea turtles tangled in nets. They also removed a 28-foot by 7-foot “super net” that extended 16 feet deep and weighed 11½ tons. The net, which had to be cut it into three pieces and towed separately back to the Sette, had destroyed coral in the atoll and posed a huge wildlife entanglement risk, according to the team.

The team also recovered two 30-foot boats at Pearl and Hermes Atoll, which are suspected to have come from Japan as a result of the 2011 tsunami. Two additional boats were also spotted but unable to be recovered. Following the mission, NOAA scientists will inspect the boats and work with the Japan consulate to determine their origin. Similar boats have turned up in Hawaii, the U.S. West Coast, and Canada over the past three years.

On the shorelines of Midway Atoll National Wildlife Refuge, also part of the monument, the team surveyed and removed nearly 6¼ tons of plastic trash, paying special attention to the bottle caps and cigarette lighters that are commonly eaten by birds. They removed and counted thousands of pieces of plastic, including 7,436 hard plastic fragments, 3,758 bottle caps, 1,469 plastic beverage bottles and 477 lighters.

The divers worked out of small boats launched from the Sette, systematically surveying coral reefs at Maro Reef, Pearl and Hermes Atoll and Midway Atoll. They used maps marked with GIS locations. Once the divers located a net, they removed it from the coral and into the boat.

NOAA has led this mission every year since 1996, removing a total of 904 tons of marine debris, including this year’s haul. The nets are an entanglement hazard for monk seals, turtles and seabirds that depend on the shallow coral reef ecosystem for survival. They also break and damage corals as they drift through the currents, snagging on anything in their path. Once they have settled, they can smother the corals and prevent growth.

“This mission is critical to keeping marine debris from building up in the monument,” said Kyle Koyanagi, Pacific Islands regional coordinator for NOAA’s Marine Debris program. “Hopefully we can find ways to prevent nets from entering this special place, but until then, removing them is the only way to keep them from harming this fragile ecosystem.”

After the nets are unloaded from the Sette, they will become electricity as part of Hawaii’s Nets to Energy partnership with Covanta Energy and Schnitzer Steel. NOAA has sent the derelict nets from this mission to Nets to Energy since 2002, which has powered homes in Hawaii as a result.