Seas of Garbage

posted on ecology.com by Christopher Bartlett, April 4, 2012

Oceanic Garbage Soup – Choking the Food Chain

 

Floating on or just beneath the surface of the north Pacific Ocean, over 1,000 miles (1,610 km) from any landmass, lies a soup of trash; the Great Pacific Garbage Patch (GPGP). Located in the North Pacific Sub-tropical Gyre that covers approximately 10 million square miles (25,890,000 sq km), it covers an area two and a half times the size of France, the largest country in Western Europe, and is 20 percent larger than South Africa. Discovered in 1997 by Charles Moore, ironically an heir to a petroleum fortune, the GPGP is a mass of plastics, debris, and lost or discarded fishing nets.

Nearly 90 percent of all floating marine litter is plastic, a petroleum-based substance that takes decades to be broken down on land by the suns’ rays, and even longer in the cool seas where it is often further protected by barnacles and algae.

Plastic pellets used in all sorts of packaging and plastic products are the most commonly found marine pollutant. Also known as nurdles or mermaids’ tears, 50 million tonnes are produced every year. 80 percent of marine rubbish comes from land via winds and rivers, with ocean currents carrying debris from the west coast of North America to the gyre in about five years, and debris from the east coast of Asia in a year or less.

The remaining rubbish comes from ships with a typical 3,000-passenger cruise ship producing over eight tons of solid waste weekly, much of which ends up in the patch, alongside floats and other equipment illegally jettisoned from commercial and fishing vessels to avoid the cost of proper disposal in port.

Charles Moore swimming in the debris in the Great Pacific Garbage Patch. Photo courtesy algalita.org

Then there are the contents of the estimated ten thousand cargo containers that fall overboard every year. One container can hold 10,000 running shoes, 17,000 ice hockey gloves, or a million pieces of Lego. Given the number of consignments lost and the longevity of the products, there are hundreds of thousands, if not millions, of sports shoes floating in the seas.

In fact, the Garbage Patch name was coined five years before Moore’s discovery, by Seattle oceanographer Curtis Ebbesmeyer whilst studying a consignment of 29,000 plastic bathtub ducks lost from a container ship during a Pacific storm. Using oceanic current modelling software and plotting the positions where ducks were found, he became aware of a slow vortex into which debris was drawn.

Suspended Below the Surface

Unfortunately, most of the trash is not brightly coloured ducks and running shoes, but mostly small plastic particles suspended at or just below the surface, making its detection by aircraft or satellite impossible. The U.N. Environment Program estimates that 46,000 pieces of plastic litter are floating on every square mile of the oceans, whilst the GPGP when last surveyed, contained at least six times more plastic matter than plankton biomass, the bottom of the food chain.

Returning from a trans-Pacific yacht race, Moore decided to try a short-cut through the virtually windless and therefore seldom crossed North Pacific Sub-tropical Gyre (NPSG). Motoring through the area Moore was shocked by the contents of the sea. “Every time I came on deck, there was trash floating by,” he said. “How could we have fouled such a huge area? How could this go on for a week?”

Seeking the Source

As the founder of the non-profit Algalita Marine Research Foundation, he began looking into the sources of the problem and its extent. In 1999 he returned to undertake the first scientific sampling of the area he describes as two to three times the size of Texas, but that he fears could be greater than the surface area of the United States.

In June 2009, with Moore on board for his tenth mission to the area, the ORV Algalita set off on the a four-month mission to gather more data to try to gain further understanding into the wide-ranging and poorly understood potential impacts of oceanic micro-plastic pollution.

The first leg of the trip concentrated on sampling the area around Hawaii, providing both water samples from trawls and fish tissue samples for analysis back on land. It is believed that a significant amount of the plastic pollution currently cycling around the North Pacific passes around or through the Hawaiian islands, making the area a suspect for high concentration of small particle pollution as well as large ghost net pollution. The importance of these islands, with their pristine reef ecosystems, for a myriad of species means that a full understanding of how these animals and their environment are interacting with plastic pollution is needed.

Widespread Ingestion

Fish ingest small particles of plastic, mistaking them for food. Photo courtesy algalita.org

Whilst analysis of the samples is still ongoing (it is a slow process and an area for which funding is hard to find), the expeditions have discovered the widespread ingestion of plastic particles by fish that forage on plankton at night on the ocean surface. In trawls, a total of 660 fish, representing six species, were captured for future study. Of these fish, 35 percent had ingested micro-plastic particles, the record holder having 83 fragments.

Plastics absorb Persistent Organic Pollutants (POPs) from paint chips, coolants, pesticides, and metals, so when fish eat plastic matter and then bigger fish eat them, the chemicals could be bioaccumulating. Do the micro plastic particles contain POPs, and do these harmful pollutants migrate into the tissues and organs of the fish that ingest them and subsequently enter into the human food chain? Concentrations of the most frequent POPs (PCBs, DDT, and PAH – all renowned for their effects on the human organism) on nurdles collected from Japanese coastal waters, were found to be up to one million times higher than the levels detected in surrounding seawater. The new data from the NPSG could have far-reaching effects.

Although the actual analysis of the samples will take up until into 2012, visual observation comparing photos of the worst trawl in 1999 to the lightest in 2009 showed that the accumulation has not only a higher concentration of micro plastics but, according to Captain Moore, there was a record number of macro plastics. Things like parts of buoys, crates, bottles, caps, plastic popsicle sticks, umbrella handles, numerous oyster spacers, and builders’ hard hats were often found or observed floating on the surface.

“Plastics are the lubricant of globalization.” 

- Captain Charles Moore

On the last leg, the six crew members collected samples using a manta trawl with a rectangular opening of 0.9×0.15 m2, and a 3.5 m long, 333u net with a 30×10 cm2 collecting bag at a speed of 2.5 knots for an hour at a time, taking 52 samples. Sampling concentrated on the surface, where most of the items were found just below the surface tension, with only a small part, such as 55-gallon drums, breaking the surface. There were items full of air like buoys and capped bottles that floated on the surface but, above all, location in the water column depends on sea state.

If the ocean is rough, the trash is forced down deeper. When it is calm, it rises toward the surface again, although Captain Moore, the only crewmember remaining from the 1999 sampling expedition, has found plastics over 100 metres deep, using a bongo trawl. Every sample came back with large quantities of plastic particulates. Though it’s difficult to quantify just how much more without the data from the samples, according to Captain Moore, it appears to be significantly more. He estimated that the weight of the plastic debris there has doubled in a decade and is accumulating at an ever-increasing speed.

1 mile trawl sample of plastic debris of the North Pacific Gyre in 2005. Photo courtesy algalita.org

Researcher Bonnie Monteleone from the University of North Carolina said that the most shocking thing for her was “finding everyday house hold items like bottles and plastic containers that were half eaten or had large bite marks in them. Fish are eating the plastic. It might not be the fish that we eat that are eating the fish, but I can assure you the fish we eat are eating the fish that are eating the plastic.”

She became nauseated. “After witnessing the first few samples I thought, “Yep, that’s why I’m out here. But after the 20th trawl, I began hoping the sample would come back free of plastic.” She said, “Shouldn’t there be just one that doesn’t have plastic in it? But to no avail. I have to wonder if there is anywhere on this planet we haven’t polluted”.

Navigational Hazards

One major difference from 1999 to 2009, was that the amount of large items that were navigational hazards. Ghost nets that barely break the surface so it is difficult to see them until you are upon them. They can weigh up to 500 kilograms or more. “We managed to remove one that was around 200 lbs. If we had run into it, it could have done serious damage,” said Monteleone. The crew also had a near miss with a telephone pole which came within a few feet of the starboard pontoon. There was also a large item strapped to a wooden pallet that was about three feet square that they dared not approach too closely. The props were fouled several times with derelict fishing gear and went so far as to stop the engines in the middle of the night. Crewmember Jeff Ernst had to free dive under the boat to disentangle them. Even though there are no common shipping lanes nor cruise lines and very little if any fishing occurring near or in the GPGP, there is evidence of our negative plastic influence everywhere.

Plastics hauled from the Indian Ocean gyre. Photo courtesy algalita.org

If this picture wasn’t shocking enough, recent expeditions run by The 5 Gyres Project, a collaboration among AMRF, Livable Legacy and Pangaea Explorations, to the planet’s four other major gyres in the North Atlantic, Indian Ocean, South Atlantic and South Pacific, have all come back with sampling nets containing considerable quantities of plastic. Further sampling is being carried out to gain an even more accurate picture, through The 5 Gyres Project “Travel Trawl” program, where research equipment is loaned to other sailors and “citizen scientists” to collect ocean samples.

Ingestion of plastic items kills an estimated 100,000 marine animals yearly, as plastic mistaken for food fills the stomach and impedes digestion of proper nourishment. According to Pulitzer Prize-winner Kenneth Weiss’s research, young albatross are killed in their hundreds of thousands, and corpses on Midway Island have been found with all sorts of plastic matter in their stomachs, including ballpoint pen lids, toy soldiers, dinosaurs, perfume bottles, highlighter pens, and disposable lighters.

Albatross are by no means the only victims. An estimated one million seabirds choke, or become tangled in plastic nets or other debris every year. About 100,000 seals, sea lions, whales, dolphins, other marine mammals and sea turtles suffer the same fate. Furthermore, buoyant micro plastic particles ingested by small deep-sea fish may negatively affect their ability to return below and to exist in their normal habitat. Scientists already estimate that nearly half of all seabird species, all sea turtle species, and 22 species of marine mammals are harmed or killed by plastic waste through ingestion, entanglement or strangulation, before the debris has been broken down into tiny fragments.

And the Solution?

What can be done about it? For the matter that is already in the gyres, very little. Collecting it and disposing of it would be a monumental exercise that no government would be willing to fund, unless it were to start having tangible negative effects on human health.

It would appear that the only answer is to stop more plastic from getting into our oceans. Ultimately, consumption and production have to be curtailed by educating consumers and placing the responsibility on the manufacturers that produce the myriad of plastic goods and plastic packaging that are such an intrinsic part of everyday lives. But in a society increasingly reliant on plastic substances, that may be a task as big as the Garbage Patches themselves.