Ocean covers nearly 2/3rd of the earth's surface and play a central role in
earths major processes. More than a billion people worldwide depends upon food
from the ocean as their primary source of protein. Since the beginning of the
industrial era, the ocean has absorbed some 525 billion tons of CO2 from the
atmosphere, presently around 22 million tons per day.
At first scientist though this is a good thing as it decreases CO2 from the
atmosphere but after an enhanced study it was discovered that it leads to the
changing of oceans chemistry. It is estimated that about 30 to 40% of CO2
released in atmosphere is dissolved in oceans rivers and lakes out of this 25%
is anthropogenic and rest is from other sources namely animals and plants. This
uptake of excesses CO2 from the atmosphere into sea decreases the PH of sea and
leads to oceanic acidification.
PH is a scale between 0-14 used to measure the concentration of H+ ions sea
water has a PH of 7 (neither acidic nor basic) and when it decreases acidity
increases so far oceans PH drops from 8.2 to 8.1 and 0.3 to 0.4 units by end of
the century although it seems very low but impacts a lot. Acidity occurs when
the CO2 is combined with water (H2O) and form carbonic acid (H2CO3) which act as
a building blocks for the skeletons and shells of many marine organisms.
This further forms bicarbonate molecules (HCO3-) and since in water acid forms
ions so H+ ions are formed. The more H+ ions are form PH decreases and acidity
of the ocean increases. The rapid increase in the CO2 level jeopardizing the
ocean chemistry as various calcifying species, including oysters, clams, sea
urchins, shallow water corals, deep sea corals, and calcareous plankton cannot
form their shells.
Pteropod's or sea butterflies sometimes called 'potato chips of the sea' are
tiny creatures and a diet for various marine animals including zooplankton,
salmon, herring, birds and baleen whales a study shows that pteropod's shell
dissolves over 45 day when placed in sea water and by the 2050 they will unable
to make shells due to acidity and hence provide cascading effect to the marine
food chain. Moreover there is total failures of developing oysters in both
aquaculture facilities and natural ecosystems on the West Coast.
The West Coast oyster industry faces the consequence of 111 million dollar due
to acidification. Various mollusks, including mussels, scallops and clams are
near to extinction as these animals create their shells from calcium carbonate
which protect their body from diseases oceanic conditions and predators due to
the increase in CO2 level the concentration of H+ ions increases which does not
allow the carbonate ions to combine with calcium and hence their shells were
more vulnerable to dissolution due to lack of calcium carbonate (CACO3).
In a recent paper, coral biologists reported that ocean acidification could
compromise the successful fertilization, larval settlement and survivorship of
Elkhorn coral, an endangered species a research indicates that, by the end of
this century, coral reefs may erode faster than they can be rebuilt. Although
coral reefs cover just one percent of world continental shelves, coral reefs
serve as important habitat to as many as 1 to 3 million species, including more
than 25% of all marine fish species.
These millions of species feed, reproduce, shelter larvae and take refuge from
predators in the vast three-dimensional framework offered by coral reefs these
reefs are also very important to various coastal communities and economies.
Economists valued the reefs to 30 to 170 billion dollars per year as these reefs
provide goods and service to society including fishery, tourism, and aesthetic
values costal protection. Oceanic acidification also depress the metabolic rate
and immune response in marine organisms.
Currently we are forcing the marine species to live in a condition which is
undesirable to them we don't know what will happen but one thing is quite clear
that they will likely to be punished into extinction. Although there will be
some ecological winner such as algae, sea grasses, jellyfish to whom acidity is
the favorable condition as they need CO2 in large amounts to expand. But
moreover we were devoid of those animals on which we depend upon and composed of
those which have less value.
Apart from values excess of these species don't resembles the healthy ocean it
only signifies ocean which is out of balance. In order to tackle this problem
states must unanimously agree to reduce the CO2 emission from 475ppm to 350ppm,
restriction must imposed on overfishing and burning of fossil fuels we should
take initiative to grow mangroves, sea grasses, salt marshes which is also
known as blue carbon.
An international and national committee must be formed composed of scientist and
various stakeholders which will provide detailed data, analysis, products,
useful to policy advisors decision maker's politicians the members of the
committee must also put a close watch on shores of oceans and insure PH does not
drop to 0.2 units. Technique of iron fertilization must be adopted by different
countries which provide iron to iron in poor areas of the ocean to increase
photosynthesis in phytoplankton's as they are the main organism to convert
excess CO2 into carbohydrate and oxygen gas.
This Oceanic acidification is also called an 'evil twin' of global warming which
is responsible for climate change so by controlling one other will also get
controlled. A study by Indian scientists predict that the Arabian Sea and Bay of
Bengal may be hit by acidification at an unprecedented level and India being the
member of Paris Accord which aims for reduction in CO2 by 2030 does not have any
comprehensive legislation on CO2 emission which is the need of the hour. India's
plan so far is to avoid legislation and combat the problem through policies
which does not coup up with rapid changing environment and also lack
accountability, legislation would bring accountability and subject to amendment
to counter problem.
Apart from governmental efforts the thing which we as an ordinary citizens can
do is to pledge to reduce the energy use at home by recycling, turning off
unused lights, walking or biking short distances instead of driving, using
public transportation, and supporting clean energy, such as solar, wind, and
geothermal power. Remember oceanic acidification does not decrease immediately
there is a lag between changing our emissions and when we start to feel the
effects. So it's never too late to counter a problem so what we do in two to
three years will determine our future.