Plastic Waste in Our Oceans: Problems and Solutions

The sheer volume of plastic and other trash that is floating in
our oceans made the hunt for Malaysia Airlines flight 370 far more
difficult. The search for the missing airliner has been a harrowing
affair. After weeks of sifting through ocean refuse, the armada of ships combing
the Indian ocean now claim to be zeroing in on pings that may be emanating from
the missing airliner’s black boxes. However, this search was hampered by the
tons of garbage that are strewn across our oceans.

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One of the unexpected corollaries of the search for Malaysia Airlines flight
370 has been the increase in public awareness about the tons of garbage that
litter our oceans. In the first few weeks after the March 8 disappearance of the
passenger jet, searchers scoured huge swaths of the Indian Ocean, and found
nothing but garbage. In the process of looking for wreckage from the plane, we
received almost daily reports of possible debris from satellite images. These
finds turned out to be nothing more than floating piles of trash.

The five ocean gyres

There are five massive garbage gyres, one is located in the Indian Ocean, two
in the Pacific Ocean and another two in the Atlantic Ocean. Garbage gyres come
together as the trash gets caught in circular ocean currents. This causes stray
garbage to move until they collide and merge with one another.
University of New South Whales Researcher Erik
Van Sebille has suggested there may be a sixth garbage patch forming in the
Arctic Circle in the Barents Sea.

Plastic debris

These garbage gyres are made up of everything from appliances to cargo
containers, but they are composed mostly of plastic including around 3.5 million
tons of beverage bottles and grocery bags. Plastic constitutes 90 percent of all trash floating in the world’s oceans. The
United Nations Environment Program (UNEP) estimated that in 2006, every square
mile of ocean hosted 46,000 pieces of floating plastic.

Van Sebille said each of these gyres, “contains so much plastic that if you
were to drag a net through these areas you would pull up more plastic than
biomass.”

Plastic waste in the oceans poses a serious environmental problem. UV rays
from the sun and salt from the sea water cause the plastic to break down, which
releases chemicals into the water that then enter the food system according to
the Scripps
Institute at the University of California San Diego.

Plastic poses some unique problems for ocean ecosystems. Some plastics
decompose within a year of entering the water, leaching to potentially toxic
chemicals such as bisphenol A, PCBs, and derivatives of polystyrene.

Unlike organic debris, plastic does not biodegrade. The plastic in these
debris fields will last for hundreds of years. Over time, plastic in the oceans
disintegrates into ever smaller pieces while remaining a polymer. This process
continues down to the molecular level and concentrates in the upper water
column. Plastic pollution in the form of small particles (diameter less than 5
mm) is called “microplastics.”

Wildlife impacts and the food chain

According to UNEP, at least 267 species worldwide are impacted by plastic
debris in the oceans. As the plastic disintegrates, it ultimately becomes small
enough to be ingested by a wide range of life forms. Plastics are deadly to a
number of species including marine birds and sea turtles. Various investigations
including research by Charles Moore found that in some places the overall
concentration of plastics was seven times greater than the concentration of
zooplankton. Plastics enter the food chain when ingested by aquatic
organisms and the impacts go all the way up the chain to humans.

Researchers have discovered that floating debris can also absorb organic
pollutants from seawater, including PCBs, DDT, and PAHs. When consumed, plastic
has both toxic effects and disruptive impacts on the endocrine system.

Source of debris

It is crudely estimated that 80 percent of the garbage comes from land-based
sources and 20 percent is from ships. According to a 2011 EPA report titled,
Marine Debris in the North Pacific:

“The primary source of marine debris is the improper waste disposal or
management of trash and manufacturing products, including plastics (e.g.,
littering, illegal dumping) … Debris is generated on land at marinas, ports,
rivers, harbors, docks, and storm drains. Debris is generated at sea from
fishing vessels, stationary platforms and cargo ships.”

Much of the land-based sources of ocean waste originates from the great
rivers from around the world

Size of debris fields

According to some media reports, ocean borne garbage is up to “twice the size of
the continental United States”. Although these estimates are hardly precise,
they range from 700,000 square kilometres (270,000 sq mi) to more than
15,000,000 square kilometres (5,800,000 sq mi).

Investigations, raising awareness and cleanup efforts

There are a wide range of innovative efforts to raise awareness about ocean
garbage and cleanup these debris fields. In 2008, a sailing voyage called the
“Junk Raft” sought to raise awareness with a three month voyage across the
Pacific. Also in 2008, Richard Sundance Owen formed the Environmental
Cleanup Coalition (ECC) a collaborative effort to address the issue of North
Pacific pollution. They work on developing methods to safely remove plastic and
persistent organic pollutants from the oceans.

In 2009, Project Kaisei launched a cleanup study that included two
vessels that set out to research and assess the feasibility of commercial scale
collection and recycling of ocean borne garbage.

Another 2009 investigation titled the SEAPLEX expedition, involved a 19 day
ocean journey by a group of researchers from the Scripps Institution of
Oceanography. They spent 19 days studying the distribution of plastic in the
gyre which resulted in the most rigorous study to date.

In 2012, Dutch Aerospace Engineering student Boyan Slat unveiled a concept
for removing large amounts of marine debris. He subsequently formed an
organization called The
Ocean Cleanup. This approach is not only cost effective, it is
potentially profitable. His idea involves an anchored network of booms that
world work like a giant funnel. Propelled by the ocean’s surface currents,
debris would drift into specially designed arms and collection platforms where
it would be separated from plankton and recycled. Slat’s calculations suggest
that using his methods, 7.25 million tons of plastic can be removed from garbage gyres
in as little as five years.

South Korean designer Sung Jin Cho has conceived of another innovative
approach to removing plastic waste from water. His concept is known as
the Seawer Skyscraper. This massive yet portable, self-supported solar-hydro
power station, generates electricity using seawater while removing plastic
waste. The Seawer filters ocean water and removes plastics and other
particles which are recycled in an onboard plant. The purified seawater is
stored in a large sedimentation tank at the bottom of the structure before it is
released back into the ocean.

Despite these creative approaches to removing debris from the world’s oceans,
they will not be able to reach the majority of plastic which have accumulated on
the ocean floor.

Of the more than 200 billion pounds of plastic the world produces each year,
about 10 percent ends up in the ocean. Much of which (approximately 70
percent) sinks to the bottom and harms life on the ocean floor.

In the North Sea alone, Dutch scientists have counted around 110 pieces of
litter for every square kilometre of the seabed. This amounts to a staggering
600,000 tonnes in the North Sea alone. This garbage can smother the sea bottom
and kill the marine life.

While efforts to clean up the plastics are laudable, they are not a
definitive solution. Plastics break down into smaller polymers and suspend
underneath the surface or on the ocean floor making them hard to see and difficult
to clean up.

Plastic waste comes from almost every country in the world which makes ocean
garbage an international problem requiring international solutions. While we
can dispose of our waste more responsibly, the problem extends far beyond waste
management. With Around 100 million tonnes of plastic products being produced
each year, we need to find solutions at the source.

We need to find alternatives to conventional plastics that are biodegradable
and do not contain harmful chemicals.

Source: Global
Warming is Real