Our oceans: The ultimate sump

The oceans are among our biggest resource and also our biggest
dumping grounds.

By Quamrul Haider
Jun 8 2019 (IPS-Partners)

(The Daily Star) – Today is “World Oceans Day,” a day
observed worldwide to raise awareness about the crucial role the
oceans play in sustaining life on Earth. It is also a day to
appreciate the beauty of the oceans that “brings eternal joy to
the soul.”

The oceans are among our biggest resource and also our biggest
dumping grounds. Because they are so vast and deep, many of us
believe that no matter how much garbage we dump into them, the
effects would be negligible. Proponents of dumping even have a
mantra: “The solution to pollution is dilution.” Really! In
case they don’t know, garbage dumped into the oceans is
continuously mixed by wind and waves and widely dispersed over huge
surface areas.

There is a zone in the Pacific Ocean, called The Great Pacific
Garbage Patch, which is a gyre of marine garbage twice the size of
Texas. The garbage, mainly microplastics, were carried there by
strong currents from other parts of the ocean. This is not the only
floating garbage in our oceans. The Atlantic and Indian Oceans have
their own garbage patches. Worse yet, the sheer size of the patches
is making clean-up efforts an extremely difficult task.

Surely, human activities are impacting the oceans in drastic
ways. Some of the anthropogenic environmental issues that are
affecting the oceans are plastic pollution, oil spills, climate
change and noise. One of the most dangerous threats the oceans may
face in this century is radioactive pollution.The oceans are no
longer “The Silent World” of the famous oceanic explorer
Jacques Cousteau. Today, they are being acoustically bleached by
noise from seismic blasts used for offshore oil and gas
exploration, marine traffic and military sonar.

Each year, we dump nearly eight million tonnes of
plastic—mostly grocery bags, water bottles, yogurt cups, drinking
straws and plastic utensils—into the oceans. Recently, plastic
has been discovered in the deepest part (11 kilometres) of the
world’s oceans, Mariana Trench in the Pacific Ocean. Extremely
elevated concentration of PCBs, an environment-damaging chemical
banned in the 1970s, have also been found within the sediment of
the trench.

While it takes hundreds of years for plastics to decompose
fully, some of them break down much quicker into tiny,
easy-to-swallow particles that can easily be ingested by marine
species causing choking, starvation and other impairments.

Pollution of the oceans by oil spills has been one of the major
concerns for a long time. The primary source of spill is offshore
drilling. The process is inherently dangerous and thus, is prone to
accidents. When accidents happen, and they do happen without
warning, they cause massive damage to the environment—aquatic and
shore—that persists for decades to come. Some oil spills happen
when tankers transporting petroleum products have accidents.

If the layer of the oil is thick enough, it smothers creatures
unable to move out from under it. Besides, swimming and diving
birds become covered with oil, which mats their feathers, reducing
their buoyancy and preventing flight. The insulative value of
feathers is also lost and the birds quickly die of exposure in cold
water.

The world’s largest oil spill was not an accident; it was the
result of the Persian Gulf War in 1991. The second worst disaster
was the spill by BP’s Deepwater Horizon offshore rig in the Gulf
of Mexico in April 2010. Both incidents killed tens of thousands of
birds, marine mammals, sea turtles and fish, among others.

Land and oceans together absorb slightly more than half of all
the carbon dioxide emissions, with the oceans taking a greater
share. When carbon dioxide dissolves in water, it forms carbonic
acid. Various studies estimate that if we keep on pumping carbon
dioxide into the atmosphere at the current rate, then by the year
2100, the water of the oceans could be nearly 150 percent more
acidic than they are now. Such a large increase in acidity would
upset the productivity and composition of many coastal ecosystems
by affecting the key species at the base of the oceanic food webs.
It would also reduce calcium carbonate, which is essential for
building the shells and skeletons of creatures like mussels, clams,
corals and oysters.

Because oceans absorb more than 90 percent of the heat that is
added to the climate system, sea level is changing, albeit
unevenly. It is changing unevenly as oceans do not warm uniformly
across the planet, with the southern oceans warming at a faster
rate. In addition, global reef systems are slowly migrating
poleward as oceans around the world continue to warm.

The single most significant contribution to rising sea level is
from the thermal expansion of water. Melting ice makes the second
most important contribution, but only melting of land-based
ice—glaciers, ice caps and ice sheets—is significant. Ice that
is already floating in the water—iceberg—makes essentially no
change in sea level when it melts, because the greater density of
water offsets the volume of ice that is not submerged. Other
factors that contribute to the rise in sea level include wind and
ocean circulations, depth of the oceans, deposition of sediments by
river flows and alteration of the hydrologic cycle by humans.

According to some studies, global sea level rose by about 18 cms
during the last century. In the worst-case scenario, sea level
could rise by two metres by the end of the year 2100. Arguably,
rising sea level is among the potentially most catastrophic effects
of human-caused climate change.

The oceans are no longer “The Silent World” of the famous
oceanic explorer Jacques Cousteau. Today, they are being
acoustically bleached by noise from seismic blasts used for
offshore oil and gas exploration, marine traffic and military
sonar.

Unlike plastic pollution, noise pollution does not have the
visual impact that is needed to spark an outcry and force action.
It is an invisible menace that is drowning out the sounds of many
marine animals, including fish, use for navigation, communicating
with each other, finding food, choosing mates and warning others of
potential dangers.

Whales and dolphins are particularly vulnerable to noise
pollution. The deafening seismic blasts and the ping of sonar are
responsible for the loss of their hearing and habitat, and
disruption in their mating and other vital behaviours. The
disappearance of beaked whales in the Bahamas in recent years have
been attributed to testing of US Navy sonar systems in the
region.

From 1946 through 1993, nuclear countries used the oceans to
dispose of radioactive wastes. The United States alone dumped more
than 110,000 containers of nuclear material off its coasts. Russia
dumped some 17,000 containers of radioactive wastes and several
nuclear reactors, including some containing spent nuclear fuel.

It is highly likely that radioactive wastes would eventually
leak out of the containers because of poor insulation, volcanic
activity, tectonic plate movement and several other geological
factors. Indeed, last month, UN Secretary General Antonio Guterres
confirmed that a Cold War era concrete “coffin” filled with
nuclear waste is leaking radioactive material into the Pacific
Ocean. Since radiation from nuclear wastes remains active for
hundreds of thousands of years, their dangerous effects will linger
for a long time and will have lethal impact on marine life.

Furthermore, six nuclear submarines—4 Russian and 2
American—lost as a result of accidents are lying at the bottom of
the oceans. They represent serious threat of radioactive
contamination of the oceans, too.

One of the biggest contaminations due to radiation was caused by
a series of nuclear tests conducted by the USA on the sea, in the
air and underwater at Bikini Atoll in the North Pacific between
1946 and 1958. The French nuclear tests carried out during
1966-1996 in French Polynesia are responsible for other cases of
intense radioactive pollution of marine ecosystems.

Clearly, we are using the oceans as the ultimate sump, partly
because their very immensity seems to preclude any long-term
effect, and partly because they belong to no one. This cannot
continue indefinitely because in order for us to survive, we have
to protect the oceans. Lest we forget, life emerged from the oceans
and the source of most of the oxygen we breathe are the oceans.
They have been an endless source of inspiration to humankind.

Quamrul Haider is a Professor of Physics at Fordham
University, New York.

This story was
originally published
by The Daily Star, Bangladesh

The post Our oceans:
The ultimate sump
appeared first on Inter Press Service.

Source: FS – All – Ecology – News
Our oceans: The ultimate sump