The large mass of garbage in the northern Pacific Ocean, known as the Great Pacific Garbage Patch, is causing plastic debris to scatter along the beaches of Hawai‘i.
According to UH Senior Researcher Nikolai Maximenko at the School of Ocean and Earth Sciences and Technology (SOEST), microplastics are the main debris found along the beaches of Hawai‘i.
“Anytime on any beach in Hawai‘i you can see colorful particles of micro plastics on the beach,” Maximenko said.
Larger plastics found in the garbage patch form into microplastics from decay, due to sunlight exposure. Microplastics measure anywhere from one millimeter to one centimeter. Northeast trade winds then carry micro plastics from the garbage patch to the beaches of Hawai‘i.
Located between California and Hawai‘i, he said the garbage patch is trapped in a gyre — or spiraling ocean currents — that measures about 30 degrees latitude.
“The garbage patch has trapped floating debris for tens of years,” Maximenko said.
Maximenko added there are five confirmed garbage patches in the world that are located in the north and south Pacific, north and south Atlantic, and southern Indian Ocean.
UH field research
According to SOEST Research Associate Tara Clemente, in 2008 UH researchers took a vessel to the North Pacific garbage patch at a cost of about $37,000 per day.
“We were lucky, or not lucky depending on how you look at it. Every tow we did, as soon as we left Honolulu Harbor, we got plastic,” Clemente said.
The crew ended up with roughly 52,000 to 556,000 plastic fragments per square kilometer or an average of 0.3 to 0.4 pieces per square meter.
“We still don’t know the fate of where all the plastic is, and I think that is one of the bigger issues. We know it is reaching our water ways but we don’t know how much is making it to the sea floor versus the diet in animals, and washing up on our beaches,” Clemente said.
Tracking the debris
Allen Clark, senior fellow in the Politics, Governance and Security studies area at the East-West Center, became involved in the Pacific Garbage Patch after the 2011 Tohoku tsunami.
“Right after the Tohoku disaster, there was a great concern for were all the debris from the disaster was going to end up,” Clark said.
According to Clark, a bulk of the trash is moving north of the Hawaiian Islands and headed towards the mainland and Alaskan coast. Natural currents push the bulk of trash just north of the islands.
“A lot of this material as it comes into the northern pacific comes into, more or less, along the Alaska coast and along California. But then it gets picked up into another gyre that circulates it around and there is a very large amount of this material that is very fine grained,” Clark said.
He said the debris that flows from the aftermath of the tsunami is broken up into microscopic particles very quickly. The microparticles are usually broken down into their smaller state before they reach the patch.
“As everything degenerates into microparticles it ends up getting into the food chain and that’s the real issue,” Clark said.
The future of the garbage patch hinges on the debris moving from east to west, he said.
“There is a high concentration of material in the water, but it is not something you can see visibly with your eye,” Clark said.
A specialized scanner called Zooscan is used to count and measure each piece of microplastic. The scanner is used to project maps to inform the public about data regarding the garbage patch.
The maps show debris being added to the garbage patch as a result of continuous current movements from the east and other trash sources from around the world.
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