By Yang Yang
楊揚
The Plastic Ocean
塑膠海洋
Regardless of whether they are macro- or
microplastics, both endanger marine life. The
most common problems are entanglement and
ingestion. News of turtles and dolphins caught
in nylon fishing nets are not uncommon. Marine
life suffocates in plastic bags. Turtles choke from
ingesting bottles and foam mistaken as jellyfish. Sea
birds die of nutrient deprivation from the illusion of
being full after ingestion of bottle caps.
Microplastics concern marine biologists as much
as plastics concern environmentalists. With these
tiny plastic pieces having diameters smaller than 5
mm, scientists are concerned about the hazardous
effects of ingestion. Ingestion of these tiny plastic
pieces most likely occurs due to their resemblance
to zooplanktons. According to a 2010 research
by Boerger’s team in the North Pacific Central
Gyre, approximately 35% of the fish examined
had ingested plastics, averaging 2.1 pieces per
fish [2]. Another research team led by Browne
found that these plastic pieces linger in the guts
of the animals as plastic is not biodegradable [3].
Furthermore, Teuten and coworkers have found
that marine plastics absorb toxic substances like
polychlorinated biphenyls (PCBs), which are used
in coolant fluids and the banned insecticide
dichlorodiphenyltrichloroethane (DDT) [4]. The long
duration of microplastics residing within marine
animals poses potential concern to the ecosystem.
From
afar, the beautiful blue oceans of
our planet stand mesmerizing, dazzling and clear.
Now, look closer. What if the oceans we see are not
blue, but grey and turbid, and filled with plastics?
Such is the case with the Pacific Ocean. The
truth becomes apparent on closer inspection
of what is perhaps more befitting as the Plastic
Ocean. At a first glance, one might notice large
pieces of plastic, floating crudely atop ocean
waves, not unlike the ones seen on beach shores,
readily recognized as bottles, foams, or bags. Upon
closer inspection, plastic in the midst of the waters
are generally much smaller in size.
According to the samples first brought back
by researcher Moore in 2001, the ocean is like
a homogenous yellowish “plastic soup” with a
significant amount of plastic concentrated in the
waters [1]. Bigger plastic pieces like foam boards
drift from the shores to the inner oceans through
currents. Collisions break larger lumps into smaller
scraps. Prolonged exposure to UV radiation and
solar heat induce reactions with free radicals
termed photo-degradation, and the scraps soaked
in waters degrade into yet smaller fragments known
as microplastics. In other words, a soft drink bottle
from the ocean lines could be ground up into
minute fragments by the time it reaches the center
of the ocean.
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