Ocean Acidification
The global issue I have chosen to
research is ocean acidification. Ocean acidification is a bi-product of
increased CO2 in the atmosphere. When
excess CO2 is present in the atmosphere, it is dissolved into the ocean and
forms carbonic acid. Carbonic acid is usually used to buffer the ocean so that
it may stay a constant pH, but with all this excess carbonic acid not
buffering, it actually makes the ocean more acidic. This is a problem because
as the ocean becomes more acidic the more readily it dissolves calcium
carbonate and in turn has drastic effects on marine animals with calcium
carbonate shells.
This is exceeding important because
most calcifying organisms are extremely ecologically and economically
important. Examples of an ecologically important organism are pteropods.
Pteropods are the base of many ocean food webs and provide nutrition to many
other marine organisms. If they were to be eliminated from the food web, the
entire food web would be out of whack.
An example of an economically organism would be the many kinds of
shellfish. Many people rely on the ocean as their source of food and if these
organisms were to no longer exist not only would there be less food available,
but there would also be detrimental effects on the economy. Another harmful
effect of ocean acidification would be the lowering in growth rates of corals.
Corals serve as storm protection for the shore and are also the homes of many
bright and colorful creatures. A loss in coral would be more severe effects on
shores from storms and also a complete loss of a unique ecosystem.
So far there is only one proposed fix for
ocean acidification, iron fertilization. What that entails is the dumping of
iron into the ocean to spike photosynthesis rates and draw out a lot of CO2
from the atmosphere. However, this is highly impractical and it may do more
damage to our environment than good. Overall, the only thing we can do now is
hope to reduce our CO2 emissions and hope all turns out well. Unfortunately,
this is not a quick fix and will take many, many years to alleviate this
problem.
Citation:
(n.d.).
Retrieved from NOAA website: http://www.pmel.noaa.gov/co2/story/Ocean
Acidification
Overfishing
Overfishing is caused, simply by the
fact that we catch 2-3 times more fish than we actually need and it is causing
degradation in the whole marine ecosystem. Catching too many fish makes it
difficult for the fish to maintain their population, because in addition to the
fishing, their natural predators are also still hunting them. Not enough adult
fish are left to maintain the population, and so they began to drop
drastically.
·
52% of fish stocks are fully
exploited
·
20% are moderately exploited
·
17% are overexploited
·
7% are depleted
·
1% is recovering from depletion
What this means is that 52% of the
world’s fish population are being fished enough that they can still keeping
their population relatively well-maintained, however they could begin to begin
to decline with any additional fishing. Moderately exploited fish are fish that
are beginning their decline. Over exploited fish are at the final stage of
maintaining their population, and if were fished even slightly more, they would
begin a steady decline. And depleted were so overfished that they are close to
gone.
People
are beginning to realize that the oceans are not never-ending as we once thought.
The ecosystems are very delicate, just like those on land and the overfishing
problem is causing a huge strain on them. Overfishing of fish also causes a
decline in marine mammals, sharks, sea birds, and noncommercial fish.
Fish on the red list include:
Alaska Pollock
Atlantic Cod or Scrod
Atlantic Halibut (US and Canadian)
Atlantic Salmon (wild and farmed)
Atlantic Sea Scallop
Bluefin tuna
Big Eye Tuna
Chilean Sea Bass (also sold as Patagonia
Toothfish)
Greenland Halibut (also sold as Black halibut,
Atlantic turbot or Arrowhead flounder)
Grouper (imported to the U.S.)
Hoki (also known as Blue Grenadier)
Monkfish
Ocean Quahog
Orange Roughy
Red Snapper
Redfish (also sold as Ocean Perch)
Sharks
Skates and Rays
South Atlantic Albacore Tuna
Swordfish
Tropical Shrimp (wild and farmed)
Yellowfin Tuna
Red List Criteria
Fisheries that fall into any one of the
following categories are considered "Red List" candidates:
* Fishery exploits endangered, vulnerable and/or
protected species, and species with poor stock status;
* Fishery causes habitat destruction and/or
leads to ecosystem alterations;
* Fishery has negative impact on other,
non-target species;
* Fishery is unregulated, unreported, illegal or
managed poorly; and
* Fishery has negative impact on local, fishing
dependent communities.
Coral Reef Destruction
Coral reefs are underwater structure mainly
constructed of calcium carbonate concealed by corals. They are colonies where tiny organisms and
animals reside in order to obtain various nutrients in the seawater. The ideal living conditions for corals reefs
are in warmer temperatures, shallow, clear, and agitated waters. They can be found throughout the world’s
marine ecosystems and are extremely important to our marine environments. They provide a sense of shoreline protection
in our waters as well as ecosystem services to tourism. They have the ability to benefit a location
more than most of the world is aware of.
Coral reefs are massive structures of limestone deposited by living
things, the main depositor of limestone which attributes to these reefs are
corals.
Coral: "Although Coral is often mistaken for a rock or plant, it is actually composed of tiny, fragile animals called coral polyps. When people say coral they are referring to these little animals and the skeletons they leave behind after they die." (Paragraph 3) Currently, threats are
increasing to our coral reefs around the world which potentially hold detrimental
results. The following are the top reasons
why the depletion of corals reefs is becoming abundant which are going to be a
serious problem for the world in the future.
1.)Ocean Acidification:
“The oceans have absorbed approximately 525 billion
tons of carbon dioxide from the atmosphere, or about one third of the
anthropogenic carbon emissions released. This absorption has benefited
humankind by significantly reducing the greenhouse gas levels in the atmosphere
and minimizing some of the impacts of global warming. However, the ocean's
uptake of carbon dioxide is having negative impacts on the chemistry and
biology of the oceans.” (Paragraph 6)
2.) Ocean
Warming and Coral Bleaching: This is caused by the accumulation of heating
causing gasses such as carbon dioxide in the atmosphere. It is harmful because these gasses act as a
heat blanket which prevents the heat from the sun to get to the reefs. This process essentially heats the
temperatures of the water which coral are extremely susceptible to causing
their demise. Water temperature
increases leads to coral bleaching which is the act of coral polyps expelling
the algae within them making corals lose their energy and not be able to
project it into the revelation of the reef.
3.)Water
Pollution: Pollutants such as oil and gas are infecting the waters around the
world therefore infecting the coral reefs which live there. These pollutants tend to increase the amount
of nitrogen present around coral reefs resulting in an overgrowth of algae
which smothers and suffocates the reefs.
Sources:
These original research documents were done by my group members and I while deciding what global issue we wanted to continue researching. We decided on the last one, coral reef destruction.
