YSM Issue 90.4

alumni
FEATURE
ESSAY
CONTEST
BREAKING THROUGH OCEAN ACIDIFICATION
►BY CLARA BENADON from poolesvile high school
As a Marylander, one of my favorite things to do is to make the
trek up to the Chesapeake Bay. Its sparkling waters and abundant
wildlife make it a prime jewel of the East Coast. Nothing can compare
to the experience of paddling down the Potomac River on a
sunny day, the boughs of a sycamore arching overhead.
Apart from being a stunner, the Bay provides major cultural and
economic benefits. Its unique way of life is perfectly encapsulated
in the small towns of Smith Island, where watermen make a living
from the estuary’s riches. On a recent visit, one local said, “We
truly build our lives around the water.” From the individual fisherman
to larger commercial operations, the Chesapeake provides
$3.39 billion annually in seafood sales alone—part of a total economic
value topping $1 trillion.
The stability of these waters is endangered by growing ocean
acidification due to absorption of carbon dioxide from the atmosphere.
Acidification disintegrates the protective carbonate coverings
of shellfish, killing off large amounts of oysters, mussels, and
scallops. Without a thriving population of oysters, which filter the
Bay, harmful pollutants run rampant. Acidity also causes low oxygen
levels, hindering fish respiration. Even with survivable oxygen
levels, low pH can be fatal for fish.
The plummeting numbers of these Chesapeake staples make a
dent on the economy. According to the Chesapeake Bay Foundation,
Maryland and Virginia have suffered losses exceeding $4
billion over the last three decades stemming from the decline of
oyster health and distribution. High acidity stunts oyster growth,
and shellfish fisheries cannot profit from the smaller shells.
The losses aren’t economic alone. An estimated 2,700 species
call the Bay their home, and the loss of even one species causes
a ripple effect through the entire food web. According to a 2004
study in Science, the survival of threatened and nonthreatened
species is closely intertwined. Moreover, biodiversity keeps in
check the amount of carbon dioxide in any body of water. Now,
zooming out from the Chesapeake Bay, skyrocketing acidity is
present in almost every aquatic biome on our planet. When pH
is low, coral reefs cannot absorb the calcium carbonate that makes
up their skeleton. Corals—along with snails, clams, and urchins—
disintegrate. A particularly disturbing image of ocean acidification
is its effect on the neurology of fish. Their decision-making skills
are significantly delayed to the level where they sometimes swim
directly into the jaws of predators.
Economically, the UN estimates that ocean acidification will
take a $1 trillion bite out of the world economy by the year 2100.
This massive cost has direct human implications, including its
harm on health, job security, and cultural heritage. In addition,
the economies of many countries are wholly dependent upon reef
-based tourism and other activities built around the water.
We need a solution to our world’s rapidly acidifying oceans;
solving this problem would be beneficial on an unprecedented
scale. Methods that at first appeared brilliant have either been limited
by their feasibility or have been rejected due to their negative
side effects, ultimately prolonging the search for a solution.
The method of dumping significant iron sulphate into the water
is based on the principle that iron fertilizes phytoplankton, or
microscopic organisms found in every body of water. The energy
phytoplankton gain from the iron allows them to bloom, absorbing
CO 2
from the atmosphere and the ocean. When the phytoplankton
die, they sink to the bottom of the ocean, locking the
CO 2
there for centuries. In 1988, the late oceanographer John
Martin proclaimed, “Give me a half tanker of iron, and I will give
you an ice age.” It is theorized that fertilizing two percent of the
Southern Ocean could set back global warming by ten years.
Why not implement this magic fix? A 2016 study in Nature determined
that the planktonic blooms would deplete the waters of
necessary nutrients. Additionally, when the large bloom dies, it
would create large “dead zones,” areas devoid of oxygen and life.
Side effects aside, this technique may be entirely ineffective. Carbon
dioxide may simply move up the food chain when the phytoplankton
are eaten and be respired back into the water. This was
observed when the 2009 Lohafex expedition unloaded six tons of
iron off the Southern Atlantic.
Alternatively, planting kelp is less drastic. Revitalizing expansive
forests of algae has proven to be effective in sucking up underwater
CO 2
. Kelp grows as quickly as 18 inches a day, provides a habitat
for marine species, and removes nutrient pollution. Researchers
from the Puget Sound Restoration Fund, who have been monitoring
the capability of this process, have found that kelp forests are
effective at diminishing acidification on a local scale. While planting
carbonsucking species across the ocean would not be a feasible
global solution, kelp forests could help solve the acidification crises
found in less expansive areas.
To date, there is no straightforward fix to combat ocean acidification.
If a scientific breakthrough were to occur, it would perhaps
be comprised of a combination of methods. However, as science
continuously evolves, the key to deacidifying our oceans may well
turn out to be something beyond our wildest dreams.
24 Yale Scientific Magazine October 2017 www.yalescientific.org