Last week, a team of 17 National Oceanic and Atmospheric Administration (NOAA) divers returned from a mission in which it removed 57 tons of debris from the Northwestern Hawaiian Islands.
The divers traveled on the NOAA ship Oscar Elton Sette for a 33-day mission to remove marine debris from Papahanaumokuakea Marine National Monument in Hawaii. The monument is a World Heritage Site and one of the largest marine conservation areas in the world. Most of the debris removed was either fishing nets or plastic letter.
NOAA has led missions to clean marine debris every year since 1996, removing 904 tons in total, including the 57 tons removed on this latest mission.
The Northwestern Hawaiian Islands include 5,178 square miles of the least disturbed coral reef habitat in U.S. waters. Divers found three sea turtles tangled in nets at Pearl and Hermes Atoll. The divers removed almost 6.25 tons of plastic trash on the shorelines of Midway Atoll National Wildlife Refuge. At the end of the voyage, they removed 7,436 hard plastic fragments, 3,758 bottle caps, 1,469 plastic beverage bottles and 477 lighters.
“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.”
The Great Pacific Garbage Patch
Where does all of that debris come from? It is part of the Great Pacific Garbage Patch, a huge collection of marine debris in the North Pacific Ocean spanning waters from the North American West Coast to Japan. It is also called the Pacific Trash Vortex, and it is the largest plastic dump on earth. Most of the debris is not biodegradable and much of it is plastic, which breaks down into small pieces known as ‘microplastic.’
About 80 percent of the debris in the Great Pacific Garbage Patch comes from land-based activities in North America and Asia, and 20 percent comes from boaters, offshore oil rigs and large cargo ships. The majority of the debris from ocean-based activities is fishing nets, about 705,000 tons in total.
Captain Charles Moore first discovered the Great Pacific Garbage Patch in the early 1990s when he sailed through an area between Hawaii and the mainland that is rarely traveled. During a week, he noticed a steady stream of plastic debris float by although he was hundreds of miles from land. Scientists have collected up to 750,000 microplastic pieces in just one square kilometer of the Great Pacific Garbage Patch, which equals about 1.9 million bits per square mile. Most of the debris comes from plastic bags, plastic water bottles, bottle caps and Styrofoam cups. Scientists predict it will likely double in size in the next 10 years.
In 2001, scientists documented that plastic particles outnumbered plankton by a factor of 6:1, or for every pound of plankton in some parts of the Pacific gyre, there were six pounds of microplastic. In one area, there was found to be an average of 334,271 pieces per square kilometer . Some fish and birds are eating the microplastic pieces. Five to 10 percent of fish in the area contain small pieces of plastic.
Where does all of the microplastic come from? Seven billion pounds of non-recyclable plastic is created every year. Unfortunately, some of it ends up in the Pacific Ocean.
Image credit: Bo Elde