Ocean Trash and the Five Gyres

Plastic Marine Debris

The legendary Pacific Garbage Patch, or trash vortex, lies in a region of the North Pacific Ocean where the northern jet stream and the southern trade winds, flowing in opposite directions, create an immense, gently rotating whirlpool of water called the North Pacific Gyre. The vortex traps tons of plastic garbage at its center— literally tons. That is the bad news. The slightly better news is that there is no giant island of solid garbage floating in the Pacific. There are millions of small, even microscopic, pieces of plastic floating over a roughly 5000 square km area of the Pacific. This amount has increased exponentially over the past 40 years.

Rather than an island of trash floating on the ocean, this garbage patch is composed almost entirely of tiny bits of plastic, called microplastics which can’t always be seen by the naked eye. Even satellite imagery doesn’t show a giant patch of garbage— just a humongous cloudy soup. This soup does carry larger items, such as fishing gear, shoes, buoys…

Sea of garbage in Manila Harbor--  not the Pacific Garbage Patch.
But where did this garbage go?

The reality is that nearly every piece of plastic ever made still remains on Earth, no matter whether it's been recycled, battered into microscopic bits or tossed into the ocean so it’s out of sight. While many different types of trash enter the ocean, plastics make up the majority of marine debris for two reasons. First, it’s cheap and easy to shape— an economical and workable material. And worse, plastic does not biodegrade so it lasts forever.  

How big is the problem?

While the garbage patch in the North Pacific Gyre has received a lot of attention because of its size (estimated to be twice the size of Texas) , it is not the only area where marine debris can be found. Plastic debris affects waters and coastlines around the world. Animals frequently become entangled in large pieces of debris, and can be cut, drowned, or slowed down by dragging the extra weight. Additionally, heavy gear, such as fishing nets, can damage reefs and other important habitats.

Gyres rotate in a clockwise direction in the Northern hemisphere 
and counter-clockwise in the Southern hemisphere. 

The black square shows the approximate location of the 

Great Pacific Garbage Patch. Courtesy 5 Gyres Institute.

An estimated 11 million tons (and growing) of floating plastic covers an area 700 miles northeast of the Hawaiian Island chain to 1,000 miles from the coast of California, and there are 5 major gyres in the oceans worldwide, all of which are believed to contain plastic debris which resists photochemical, biological and chemical degradation.  Research has outlined the life cycle of ocean plastic. It collects in the world's five large gyres then, as the plastic fragments, it sinks into deeper water, where currents carry it to remote parts of the globe.

Kara Lavender Law, an oceanographer at the Sea Education Association in Woods Hole, Massachusetts who has participated in studies spanning decades of surface plankton net tows reports, "The more we look, the more we find. I was surprised that they found microfibers in every core of all the regions sampled."

Apparently plastics are ubiquitous in the ocean environment. 

How is ocean trash measured? 

Ocean trash is counted through beach surveys, computer models based on samples collected at sea, and estimates of the amount of trash entering the oceans. The process of collecting and counting is meticulous, time-consuming work. It took Marcus Eriksen, co-founder of the 5 Gyres Institute, a nonprofit ocean advocacy group, more than four years, using samples gathered from 24 survey trips, to generate his estimate that 5.25 trillion pieces of debris float on the surface.

That does not count microplastics which do not float on the surface and it fudges on the data missed because most pieces of garbage in the oceans would fit in a thimble with loads of room to spare.

Discovery and growing awareness… 

While oceanographers and others predicted the existence of the Great Pacific Garbage Patch, based upon the sheer amount of plastics on land and in garbage, it was yachtsman Charles Moore who actually discover the trash vortex after competing in a race from Hawaii

Captain Charles Moore.
Courtesy Earth Island Institute.

to California. Crossing the North Pacific Gyre in 1997, Moore and his crew noticed millions of pieces of plastic floating past his ship. Charles Moore continues to raise awareness through his own environmental organization, the Algalita Marine Research Foundation. During a 2014 expedition, Moore and his team launched aerial drones, to assess the extent of the trash. According to the organization, the drones determined that there is 100 times more plastic by weight than previously measured. The team also discovered more permanent plastic features, or islands, some over 15 meters (50 feet) in length.

Those who predicted the existence of the garbage patches had noted in the past that plastic production has quadrupled since the 1980s, and that the prevalent size of the Great Pacific Garbage Patch is due in part to its location at the nexus of Asian Pacific population centers where manufacturing is high and refuse management is low in governing priorities. In fact, today it is estimated  that about 80% of the debris in the Great Pacific Garbage Patch comes from North America and Asia. Trash from the coast of North America takes about six years to reach the Great Pacific Garbage Patch, while trash from Japan and other Asian countries takes about a year.

The remaining 20% of debris in the Great Pacific Garbage Patch comes from boaters,

Sea turtle entangled in "ghost net." Courtesy Wikipedia.

offshore oil rigs, and large cargo ships that dump or lose debris directly into the sea. The majority of this debris—over 700,000 tons—is plastic fishing nets. More unusual items, such as computer monitors and LEGOs, come from dropped shipping containers which provide their own shipping hazards.

Discovery and awareness have uncovered a bit of a mystery as well. There’s loads of missing plastic. Since plastics production has quadrupled since the 1980s, there should be lots more plastic floating in the oceans than counted by scientists. It’s here, but where? There is a search underway for the missing plastic.

It is highly unlikely to have evaporated, but it could be degraded to the point where it is undetectable, or it could be simply hidden from view. The seafloor beneath the Great Pacific Garbage Patch may also be an underwater trash heap. Oceanographers and ecologists recently discovered that about 70% of marine debris actually sinks to the bottom of the ocean. This begs new questions. Not only where is the missing plastic, but in what amounts and how did it get there?
   
What harm can it do?

Let’s start with marine life. Loggerhead sea turtles often mistake plastic bags for jellies, their favorite food. Albatrosses mistake plastic resin pellets for fish eggs and feed them to chicks, which die of starvation or ruptured organs. Seals and other marine mammals become

entangled in abandoned plastic fishing nets, which are being discarded regularly because of their low cost. Seals and other mammals often drown in these forgotten nets—a phenomenon known as “ghost fishing.”

Marine food chain, drawn by Christopher Krembs, NOAA.

Marine debris can also disturb marine food webs. As microplastics and other trash collect on or near the surface of the ocean, they block sunlight from reaching plankton and algae below. Algae and plankton are the most common autotrophs, or producers, in the marine food web. Autotrophs are organisms that can produce their own nutrients from oxygen, carbon, and sunlight. 

If algae and plankton communities are threatened, the entire food chain can suffer. Animals that feed on algae and plankton, such as fish and turtles, will have less food. If those populations decrease, there will be less food for apex predators such as tuna, sharks, and whales. Eventually, seafood becomes less available and more expensive for people as well.

Plastic has acutely affected albatrosses, which traverse ­a wide swath of the northern Pacific Ocean. On Midway Island, which comes into contact with parts of the Eastern Garbage Patch,  albatrosses give birth to 500,000 chicks every year. Two hundred thousand of them die, many of them by consuming nutrition-less plastic fed to them by their parents, who confuse it for food [source: LA Times].  

There may be consequences yet to be discovered.

What can be done? 

Despite the magnitude of the numbers, Peter Ryan, a zoologist at the University of Cape Town, South Africa, who has written about tracing the evolution of marine debris research, says the problem is solvable. "Marine debris, unlike global warming, should be an easy

Plastic Pellets

thing to deal with," he says. "We have to sort out what to do with our rubbish." Ryan began tracking debris more than 30 years ago, after a colleague recommended he study seabirds that consume floating plastic pellets. The pellets were commonly used in manufacturing back then and were routinely found in harbors and other waterways. Improvements to shipping reduced pellet spillage. Ryan says, "If you go to the beach today, you struggle to find one.We can show that in every study that looks at the North Atlantic that the amount of pellets [ingested by] seabirds has decreased over the last two decades."

On the other hand, Charles Moore, the man who discovered the vortex, says cleaning up the garbage patch would “bankrupt any country” that tried it. So far, no country has taken responsibility or funded a clean-up to any of the 5 gyres, which lie so far from their coasts.

Microbeads, found in soaps and face washes, 
are a number one source for 
microplastics (photo from gizmodo.com)

Moreover, cleaning up marine debris is not as easy as it sounds. Many microplastics are the same size as small sea animals, so nets designed to scoop up trash would catch and decimate these creatures as well. Even if we could just gather garbage, the size of the oceans makes this job overwhelming. The National Ocean and Atmospheric Administration’s Marine Debris Program has estimated that it would take 67 ships one year to clean up less than one percent of the North Pacific Ocean.

The best option available today is to prevent the garbage patches from growing. Here are some suggestions-- and, once again, every little bit helps.

• Eliminate your use of disposable one-use plastics in favor of biodegradable, reusable substitutes: buy soap bars wrapped in paper; use fabric or paper shopping bags; stop buying single-use plastic water bottles.
• If forced to use plastics, recycle and dispose of them responsibly.
• Participate in coastal clean-ups of your local beaches, shores and waterways.

  

  Participate in coastal
  clean-ups

• Cigarette butts are one of the most ubiquitous beach and ocean pollutants— never drop them anywhere.
• Cut open plastic six-pack bottle straps and other straps that can trap marine life.
• Talk with family, friends, co-workers and anyone else who will listen about the oceans and growing menace of trash. 

I find this quote from Charles Moore inspirational: 

When we talk about solutions, we have to talk about a global reassessment of a product’s utility. Right now, a product is considered useful if it sells in the marketplace. The market drives consumption, and consumption is considered to be the be-all and end-all of utility. If people are buying it, it must be good for something. But that calculus is in need of revision.
The public is not given the information it needs to make good consumer choices. It doesn’t know that the plastic carries contaminants that are increasing their body-burden of industrial chemicals; it doesn’t know that there is no recycling for these products; it doesn’t know that many of these products will not even make it to a landfill – that they will end up in the ocean.
http://www.algalita.org/

More reading and other resources:

National Geographic http://education.nationalgeographic.com/education/encyclopedia/great-pacific-garbage-patch/?ar_a=1
New York Times
http://www.nytimes.com/2014/08/26/opinion/choking-the-oceans-with-plastic.html?_r=0
Natural History Magazine
http://www.naturalhistorymag.com/htmlsite/master.html?http://www.naturalhistorymag.com/htmlsite/1103/1103_feature.html