toxic plastic trash drift in the north pacific subtropical gyre final paper
TRANSCRIPT
TOXIC PLASTIC TRASH
DRIFT IN THE NORTH
PACIFIC SUBTROPICAL
GYRE
ABSTRACT Polymer-based plastic pollutants
have become a potential hazard
and disruption of the ecosystem
and environment. The North
Pacific Subtropical Gyre, where
scientist recently collected
floating debris, and then
conducted experiments. The
results indicate the NPSG
currently holds the highest
accumulation of microplastics
compared to the other four
subtropical gyres. Marine plants,
animals, and non-marine species
encounter difficult challenges as
additional debris continues to
enter and drift away from its
source. North America, China,
and Japan are the predominate
contributors responsible for land
origin pollutants. Ships,
however, lose or intentionally
cut their fishing lines which can
quickly effect organism who
sadly become entangled in the
nets. Discarded fishing line, also
manufactured out of plastic
materials, generally gets
ingested that ultimately causes
death of the animal. If a
consuming animal survives
ingesting toxic plastics, a
predator would bio-accumulate
all the toxins. Once the prey is
consumed, the predator
becomes the host of the toxic
pollutants that originally
accumulated in the first animal.
Kameron Johnson Geos 410
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Introduction
In the North Pacific Subtropical Gyre region, the dependency on plastics to
accommodate our “Throwaway Living” society has led to an increase in plastic accumulation in
the Pacific. Pre-production pellets, plastic pellets in face wash, and pollution from sea vessels
are the main contributors of plastics ending up in the pacific. The photodegradation processes,
is the process where the sun breaks down polymer plastics at the molecular level creating
micro-plastics. This paper describes the key characteristics of the North Pacific Subtropical Gyre region,
then analyzes the scientific and social scientific understanding of the photodegradation process. The
resulting effects potentially alter the entire ecological and ecosystems of the region threatening the
livelihoods of marine and non-marine species. Finally potential policy concepts are analyze that
if implemented, could provide assistance in educating the general population about the truth
behind polymer microplastics, and also development of potentially new compound mixtures.
The new mixtures could enable polluted plastic products manufactured to become the first
engineered plastic that completely degrade during the photodegradation cycle.
The North Pacific Subtropical Gyre
The North Pacific Subtropical Gyre (NPSG) resides in the planets largest body of water
and encompasses such a large area that the currents are effected by the atmospheric
conditions of prevailing winds and amount of sunlight. The prevailing warm water current flows
from the equator to the cooler waters located closer to the Artic. “The NPSG is the largest
circulation feature on our planet and the Earth’s largest contiguous biome” (Howell pg. 17).
The gyre gets its clockwise rotation due to the prevailing current distribution where a
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convergence zone forms. The center or main location of the plastic debris drift is,
“approximately 20-400 N, 120-1550 W” (Goldstein pg. 1).
This NSPG is a popular shipping lane for cargo transportation, fishing vessels, and
vacation cruises. This is the source of the human pollutants. Fishing nets and lines that either
broke or purposely discarded, are made up of nylon and other synthetic fibers all of which are
harmful to the environment. Discarded nets are literal death traps for unsuspecting animals
who become entangled leading to an untimely death by starvation or suffocation for air
breathing mammals. When an extremely large net or a bundle of a variety of synthetic ropes
reaches a coral reef, the ecological damage can be devastating to the overall health of the reef.
Live coral heads are easily caught in the fibers leading to the decrease in the population of coral
that remain to protect the shoreline of Pacific Islands.
The decade after the Second World War, the commercial use of plastics increased
exponentially causing overflow in local dumps. Also with this increased demand, pre-production
resin pellets would get spilled or mishandled during transportation and with the help of wind,
find their way into the ocean. “Every year some 5.5 quadrillion (5.5x1015) plastic pellets-about
250 billion pounds of them are produced worldwide for use in the manufacture of plastic
products” (Moore pg. 5). Once in the ocean, the molecular structure of plastic is unable to
biodegrade. Larger debris pieces break down into smaller and smaller pieces by the process of
photodegradation. Photodegradation occurs when ultra violet light rays from the sun breaking
down the molecular bonds of the plastics reducing the plastic back to a single molecular state.
Goldstein determined, “Environmental impacts of small plastic particles less than 5mm in
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diameter, termed “microplastic,” include ingestion, accumulation of toxins, and alteration of
the pelagic habitat through the addition of hard substrate” (Goldstein pg. 1).
Ingestion of microplastics by both marine and non-marine animals usually occurs by
mistaken drifting plastic debris as possible food. Small bottle caps, children’s toys, and any
small piece of plastic debris with red or bright colors are the most common items found in the
stomachs of deceased animals. “Negative effects of plastic ingestion may include intestinal
blockage, diminished feeding stimulus, lowered steroid hormone levels, delayed ovulation and
reproduction failure…may also increase toxic exposure” (Goodwin pg. 2). Another major
concern with polymer plastics is their ability to absorb other toxic waste like a sponge. Hidalgo-
Ruz describes how, “microplastics can absorb persistent bio-accumulative and toxic compounds
(PBT) from seawater, which include persistent organic pollutants (POPs) and metals” (Hidalgo-
Ruz pg. 3060). Different types of polymer plastics consist of heterogeneous assemblage with
multiple varieties in size, shape, color, specific density, chemical composition, along with other
characteristics. In fact, “microplastics have a larger surface area to volume ratio than
macroplastics and are more susceptible to contamination by airborne pollutants” (Ivar do Sul
pg. 358).
The Dangers of a Throwaway Society
It’s hard to imagine that every single day, millions and millions of humans encounter
everyday items that are produced from plastic. Plastic was developed to be used as a reliable
and durable container that would not only protect valuable supplies but also allow for mass
production to keep up with demand. Ivar do Sul states that, “plastic means “malleable” or
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“flexible” which is another favorable feature of synthetic plastics…while using versatile
materials that are inexpensive, lightweight, strong, durable, and corrosion-resistant” (Ivar do
Sul pg. 352). The overall success of plastic has inevitably caused the majority of developed
countries to become dependent on materials that are produce from production plastic pellets.
This dependency has created the ideology of “Throwaway Living’ where everyday goods are
produced with plastic resins designed into one-time-use items (e.g. bottled water, grocery bags,
and food storage bags), that have become the most abundant items that somehow makes its
way into the ocean.
The components that go into the development of plastic goods consist of several
chemicals that are harmful to the local ecosystem. According to the Environmental Pollution
journal, “most widely used synthetic plastics are low and high density polyethylene (PE),
polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and polyethylene terephthalate
(PET)” (Ivar do Sul pg. 352). The difference in the densities of the polymer based plastics effects
the buoyancy of the debris. This results in concentration layers of materials starting with the
more buoyant at the water’s surface to the less buoyant objects that are able to collect on the
ocean floor.
These multiple layers create several ecological obstacles that ultimately result in the
reduction of nutrients and changes in natural global cycles. Sunlight becomes distorted or
completely blocked disrupting the natural photosynthesis of marine plants. Once
photosynthesis stops, concentration of nitrogen and carbon becomes reduced which decreases
nutrient levels and sunlight amount. This ultimately begins increasing the concentration carbon
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dioxide of the seawater. Hayward describing how primary production is crucial to the global
carbon cycle and pelagic ecosystem structure, concludes that “the transport rate is dependent
upon the level of primary production” (Hayward pg 281). The carbon dioxide concentration
measured by the transport rate creates two categories of “new” or “regenerated” which are
determined by the limiting nutrient source.
The formation of plastic consists of lengthy chains of polymeric molecules that are a
combination of organic and inorganic materials. Organic ingredients are primarily fossil fuels
combined with inorganic elements carbon, chloride, hydrogen, oxygen, and silicon. According
to the documentary Plastic Paradise: The Great Pacific Garbage Patch, was stated that, “Plastic
has ended up being one of mankind’s perfect” (1). The material and molecular structure of
plastic does not biodegrade meaning that every single piece of plastic every produce is still on
the Earth.
As mentioned earlier, the composition of the molecular structure of synthetic plastics
allow for the easy absorption of toxic pollutants that have also accumulated due to human
negligence. Once these toxins become absorbed into the plastic, the toxins are permanently
absorbed becoming part of the animal who initially ingested the toxic debris. This process is
known as bioaccumulation, where the harmful toxins are fully absorbed into the blood and
muscles of an organism. This is where more studying is needed to determine and understand
the long-term effects on marine and non-marine organisms as well as the overall NPSG
environment. “One study estimated that more than 267 species have been documented to
ingest plastic, including mammals, turtles, and a wide variety of fish” (Goodwin pg. 1).
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Discovery and Research Methods of The Great Pacific Garbage Patch
Captain Charles Moore is responsible for discovering the drifting plastic debris in the
North Pacific Subtropical Gyre and is the leader in the debris collection and quest to better
understand the effects this unnatural material capable of altering the entire region. The Alguita
research vessel is vital in collecting and determining the micro-plastic concentration with nets
and towing methods. “Oceanographer Curtis Ebbesmeyer began referring to the garbage area
as the “eastern garbage patch” along with “estimating the area, nearly covered with floating
debris, is roughly the size of Texas” (Moore pg. 1). Goldstein makes the point that “floating
plastic was first documented in the North Pacific and North Atlantic in the early 1970’s”
(Goldstein pg. 1). However, the exact concentration and size of the NPSG toxic plastic drift is
unknown due to a lack of focus from the scientific community until the early 1990’s.
After the scientific community acknowledge the negative consequences the plastics
pose to disrupting the natural environmental balance, research and models have evolved to try
and understand the full extent of problem. The Algalita Marine Research Foundation was
founded in 1994 by Charles Moore, and is leading the quest in research, education, and
restoring the marine environment. Oceanographer W. James Ingraham Jr. working for the
National Oceanic and Atmospheric Administration (NOAA) developed the, “Ocean Surface
Current Simulator (OSCURS) that predicts the trajectory of drift originating along the coasts of
the North Pacific Rim” (Moore pg. 2). Thanks to the OSCURS model, it has been predicted that
plastic debris generally takes not quite two decades to reach the center of circulation of the
NPSG.
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Collection of both large and small pieces of debris are collected by net sampling (manta
tow & surface towing), visual observation, sub-mesoscale sampling schemata, and
oceanographic data. Once collected, barnacles that have attached themselves to larger drift
debris can be examined. The study of Gooseneck Barnacles finds, “33.5% of barnacles collected
have ingested microplastics, and the sizes and types of ingested particles were approximately
representative of microplastic found on the NPSG surface” (Goodwin pg. 8). The ingested
particles by these barnacles showed multiple plastic types including a rubber tire that was
extracted from a collected NPSG barnacle.
Another method being used to find the total accumulation of microplastics is to
compare the ratio of dry plastic mass to zooplankton biomass that have attached themselves
on debris drifting in the NPSG current. This has proven to be very difficult, if not practically
impossible due to the wide range of buoyancy of the debris plus the continuous movement of
the currents and wind. The disruption caused by this process complicates researchers efforts to
accurately determine the over area of the garbage patch. Estimated value ranges have been,
“roughly the size of Texas” (Moore pg. 1), twice the size of Texas, and even extreme estimations
such as the size of the continental United States.
Educating the General Public and Potential Political Measure’s
The consequences that are associated with the plastic pollutants drifting around the
North Pacific are finally being met. However, the general public still remains unaware of the
fact that plastic being used on a daily basis is threatening the natural balance of one of the
biggest geological features on the Earth. When I ask random individuals if they know or are
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aware of the plastic garbage patch consuming the North Pacific Gyre. Only a handful had heard
about the drifting debris but didn’t understand the possible negative implications on the
environment. The majority have never been informed about the accumulation of discarded
plastics which is altering the overall composition of the Earth’s largest body of water.
With the excessive number of the general population still unaware of this issue even
after several decades of discovery. Educational opportunities should be designed to inform and
begin the mitigation process to reduce the amount of plastic waste. A key misconception that
has been incorrectly delivered or misconstrued is that plastics are recyclable and reusable. The
truth about plastic bottles which are labeled as recycled by companies only contain 30% of
recycled plastic with the remaining 70% comprising of newly manufactured resins. The fine
print under the so called “plant bottle” is the only accurate statement informing about this gap
between new and reused plastic resin that is used in the manufacturing of the bottle. If the
general public of the United States and China where the majority of the ocean litter originates,
any reduction in new plastic pollutants ending up in the Pacific Ocean would be impossible. If
the rate of everyday, single use plastic commodities continue at the current rate, a threshold
eventually will be crossed that would inevitably change both the environment and ecosystem in
permanent ways. Today, even popular and famous beaches located on the eastern side of
Pacific Islands are covered daily with thousands and thousands of pieces of plastics which end
up being washed up onshore by the tides. Overall, “public concern about plastic debris in
marine ecosystems has grown in recent years, resulting in several governmental and non-
governmental reports” (Goldstein pg. 9).
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These governmental and non-governmental reports are important in educating the
general public on the cause and effects of the potential environmental consequences in the
Pacific. International cooperation especially with China and Japan, where the second highest
accumulation of plastic debris originates, would be a giant step forward in the mitigation policy
process. However, even with new implemented policies that would decrease the continued
accumulation of new debris, the complete stoppage of new accumulation and removal of
existing debris is physically impossible. “Considering that microplastics cannot be effectively
removed from the ocean, future studies are necessary to understand how biological agents and
abiotic factors affect the transfer, accumulation, and further breakdown of microplastics and to
describe the potential impacts of this debris” (Hidalgo-Ruz pg. 3072). Additionally, no amount
of money that is even in existence that could be used to fund the removal efforts.
With the increasing evidence of increasing polymer-based plastic pollutants ability to
disrupt the ecosystem, the biggest and most pressing policy should be funding new plastic
materials that could completely dissolve during photodegradation. This new “green” plastic
should consist of material agents that could be recycled in a similar manner as old milk jugs and
aluminum cans. Improvements have already taken place in the development and
manufacturing of plastics. I recently read an online article that a team from the University of
South Dakota had produced a plastic compound that could potentially fully photodegrade in
only 3 hours. If this turns out to become the first plastic substance to fully degrade, the
concentration of new plastic debris polluting the gyre could begin to decrease.
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Bisphenol A (BPA) is a chemical agent used in the production of many common products
most notably water bottles and receipt coatings. BPA was developed by the government as a
potential medication for birth control by increasing the amount of estrogen of the patient. After
the BPA testing trial proved the substance to be ineffective as a drug, the compound began to
be used as a coating which improved the strength and durability of plastic products. The
controversy surrounding BPA is the coating rubs off the plastic entering our bodies by simple
tasks as drinking from a water bottle or even looking over your grocery receipt. Once contact is
made, it quickly absorbs into the blood stream potentially causing higher levels of estrogen
levels in all humans. The chemical can also be absorbed by fish who ingest microplastics
developed with Bisphenol A. Scientist have recently developed reusable water bottles with
plastic produced BPA free. The development of this new plastic compound is a positive sign that
the possibility of one day discovering the right mixture that can change plastics forever.
With the human population right around 7 billion and future growth to be close to 10
billion by the end of the century, the amount of plastic goods produced and consumed could
increase tenfold. Policies and new ideas on inventing biodegradable molecular compounds that
could be used to replace the current non-biodegradable polymer plastics. Cooperation from the
leading manufacturing companies of pre-production resin pellets would be beneficial by
knowing the process that goes into producing new formulas, labs to produce, and testing
facilities to determine the quality of the experimental compound.
Conclusion
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The North Pacific Subtropical Gyre is one of only four subtropical gyre systems on the
Earth but in terms of area is the largest. Since the invention of plastics in the late 19th century
and perfected in the 20th, the plastic debris ultimately ends up permanently drifting along the
currents circular flow. Since plastics are non-biodegradable, environmental and ecological
disruptions become less and less stable as photodegradation breaks down the debris into
microplastics. Once the pieces become small enough, animals ingest the microplastics
misinterpreting it as food. Plastics and especially microplastics absorb other toxic pollutants
which once ingested by any living organism is absorbed into the muscles and passed on if the
first organism falls victim to a predator.
With the environmental interaction and consequences due to polymer-based plastic
pollutants becoming better understood, the work to start mitigating the additional
accumulation of future plastic debris, the Pacific Ocean can begin the slow process of filtering
the concentration of microplastics already drifting throughout the gyre. Founder of the Pacific
Garbage Patch, Captain Charles Moore is on record by stating, “it would take the entire world
population around a billion years to clean up all of the microplastics accumulated in the NPSG”
With this knowledge, humans as a species unable to clean up or reverse the negative effects
already caused to the environment. However, we cannot continue to believe that we are
helpless to discover new ideas and innovations that could be beneficial and environmentally
friendly. The North Pacific Subtropical Gyre is vital to the health and survival of both marine and
non-marine species that call the Pacific Ocean home.
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Maps, Images, and Tables
The poster estimates the different types of
plastic products that end up polluting the
Pacific. This propaganda poster is a good
example on educating the population of the
general waste of plastic commodities and the
negative environmental effects to those
organisms who encounter the plastic debris.
The map shows the NPSGs
rotational current flow. The
study area shows where the
most research and sample
collection site and puts in the
perspective how small the
area is producing the data.
This is a good map displaying
the size of the gyres impact.
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This data table details the
majority of the trash that has
been recovered during
research expeditions.
Surface towing net used to
collect even the tiniest
microplastics. The material
collected is then analyzed to
determine the concentration
of plastic to sea water ratio.
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Captain Charles Moore, founder of the NPSG
garbage patch, is standing on Big Island Beach
which is covered with plastic debris. High tide
brings ashore tons of polluted plastic depositing
the debris across several Pacific Islands beaches.
This Midway Atoll has become a normal occurrence as these birds
ingest plastic debris such as bottle caps and fishing line. Midway
Island contains about 70% of the species that come here to mate.
Nest are built among the washed up debris and provide thousands
of microplastics that can be feed to their chicks.
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Annotated Bibliography
1) Juliana A. Ivar do Sul, Monica F. Costa, “The Present and Future of Microplastic Pollution
in the Marine Environment.” Environmental Pollution (2014), pages 352-364.
2) Evan A. Howell, Steven J. Bograd, Carey Morishige, Michael P. Seki, Jeffrey J. Polovina,
“On North Pacific Circulation and Associated Marine Debris Concentration.” Marine
Pollution Bulletin 65 (2012), pages 16-22.
3) Miriam C. Goldstein, Andrew J. Titmus, Michael Ford, “Scales of Spatial Heterogeneity of
Plastic Marine Debris in the Northeast Pacific Ocean.” PLOS one Volume 8 Issue 11,
(November 2013), pages 1-11.
4) Miriam C. Goldstein, Deborah S. Goodwin, “Gooseneck Barnacles (Lepas spp.) Ingest
Microplastic Debris in the North Pacific Subtropical Gyre.” PeerJ (2013), pages 1-17.
5) Valeria Hildalgo-Ruz, Lars Gutow, Richard C. Thompson, Martin Thiel, “Microplastics in
the Marine Environment: A Review of Methods Used for Identification and
Quantification.” Environmental Science and Technology (2012), pages 3060-3075.
6) Charles Moore, “Trashed: Across the Pacific Ocean, Plastics, Plastics Everywhere.”
Natural History Magazine INC (2003), pages 1-8.
7) Thomas L. Hayward, “Primary Production in the North Pacific Central Gyre: A
Controversy with Important Implications.” Tree, Volume 9, (September 1991), pages
281-284.