Ocean Acidification is: the ongoing decrease in the PH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere. Seawater is naturally slightly basic (meaning pH > 7).
Why Coral Reefs are important?
They act as a natural coastal barrier, they support Biodiversity, they are an habitat for third of all fishes at some point of their lives (!) , they are a food source and support the local economy by being a tourism site. Also - many modern medical advances focus on marine organisms.
Below is a reading section and a data graphs of the processes described in the reading section. Please read the section and the accompanying graphs, and at the end answer the question. Reading section: Ocean acidification and its impacts on coral reefs Oceans play an important role in the natural carbon cycle by absorbing part of the carbon dioxide contained in the atmosphere. Calculations show that the oceans are responsible for absorbing half of the man-made emissions until 1994 and just 30% of the emissions since.
Ocean carbon dioxide absorption has another result - ocean water acidification. For the next 100 years the forecast shows a reduction of 0.5 to 0.3 pH units for the surface waters of the oceans.
A decrease in pH value entails physiological consequences for various processes, especially on limestone skeleton-based organisms (carbonate).Skeletal construction rates of limestone reef-building corals have fallen in recent years due to rising concentrations of carbon dioxide in the oceans waters.Additionally, these chemical changes in the ocean are likely to weaken existing coral skeletons and reduce the growth of reefs. This phenomenon is called coral bleaching, because the dying corals loose there colors and turns white.
A new study describes a decrease of 13% in the rate of limestone skeletal construction since 1990 at the Great Barrier Reef in Australia - the world's largest reef. Researchers attribute it to a combination of two processes: ocean acidification and rising temperatures (rising temperatures harm corals in a different way than acidification).
Models predict that with a doubling of the concentration of carbon dioxide in the atmosphere, coral reefs will stop growing altogether, and instead begin to dissolve. This prediction is very gloomy, considering the rich variety of marine species. (This section was taken and edited from the article: "The effects of global climatic change on marine ecosystems: the global situation and the implications for the marine environment in Israel", by Gil Rilob and Haim Treves, the magazine "Ecology and Environment", January 2010, No. 1, (pp 65-57)) .
Coral Bleaching at the Great Barrier Reef
The Data Graphs :
Top graph (a):
Red - Hawaii
Black - Antartics
Bottom graph (b):
Dark green blue - the Atlantic ocean
Light green blue - the Pacific ocean
(The graphs are from a presentation "Climate Change in the Middle East of the 21st century - perception and reality," Prof. Yoav Yair, School of Sustainability, Herzeliya, a seminar Communication and Environment, 3rd of December 2015)
For more information watch the attached video :
Fuel, coal, oil and natural gas combustion are producing gases, which accumulate in the atmosphere, including carbon dioxide (CO2). The accumulation of these gases causes many changes on Earth, such as rising the temperature of the atmosphere, which impacts marine organisms such as coral reefs.
How does the increase of atmospheric carbon dioxide affect coral reefs?
The topic that your question talking about is very interesting and it is obviously related to our daily life. The question is written very well and it includes distracts answers and an obvious right answer.
The reading section helps the reader to understand the question as also it is rich with information that are related to the question , the information depends on researches that makes it more interesting and relevant to our daily life.
The picture of coral bleaching is magnificent and shows the reader obviously the topic of the question , I think that there is no need to the graphs that you put , they are not clear beside the don't show the effect of CO2 on coral reefs.
I recommend to you to put this video witch shows the effects of CO2 on coral reefs :
The points on map :
let's start with the first point : The Atlantic ocean , this point shows only graphs, it needs explanation , I didn't understand how these graphs supposed to help me understanding the question.
The second point : The inter-university institute for marine sciences in Eilat , this point includes information that related to the topic of the question , it talks about coral bleaching in Eilat , it means that it shows the reader in Israel he relevant of the question to his daily life beside it helps him to solve the question.
The third point : Haifa Bay , this point is important and interesting, It shows the reader in Israel he relevant of the question to his daily life ,but I think that the text should be shorten and the picture is needless, it will enough to explain about the effect of refinery and factories on coral reefs .The video is amazing and it obviously explains the point.
The fourth point : Eilat Bay , it was so amazing to know that the coral in Eilat has a tolerance for bleaching so it survives high temperatures . The information in this point helps the reader to solve the question.
Co2 concentration in the ocean
seawater over the years
PH value in the ocean seawater
over the years.
3. From graph 2 the student can understand
that the increase in CO2 causes reduction in the PH value – You can omit the explanation about the PH reduction
in the text.
4. Addition of Acidification definition
may help the student to find the relation between acidification and reduction
of the PH value.
5. Regarding the close question, it seems
that both following answers may be valid.
increase of CO2 in the atmosphere increases the amount of CO2 dissolved in the
oceans, resulting in
water temperatures which causes a decrease in skeletal construction rates at
increase of CO2 in the atmosphere: increases the amount of CO2 dissolved in the
an increase in ocean acidity and reduces the skeletal growth rates of limestone
that the correct answer is B, answer A may still be valid, since it is known
that the increase in CO2 is related to global
warming that can raise the seawater temperature. In addition, as you showed,
high temperature of seawater may also cause adecrease in skeletal construction rates at
hi all , first of all , you choose an interesting topic and presented in an excellent manner. Attached background is rich with materials and gives a direct answer to your question , I've never been interested in this subject before but after going through your station i wanted to know why coral reefs is so important and why should people take care of it? so i recommends to add a paragraph on the importance of the coral
as we can see in the pic above the coral reefs benefit the economy , coral reefs suppoet commercial and subsistence fisheries as well as jobs and businesses through tourism and recration . Approximately half of all federally managed fisheries depend on coral reefs and related habitats for a portion of their life cycles. The National Marine Fisheries Service estimates the commercial value of U.S. fisheries from coral reefs is over $100 million.
Local economies also receive billions of dollars from visitors to reefs through diving tours, recreational fishing trips, hotels, restaurants, and other businesses based near reef ecosystems.
point in the map: John Pennekamp Coral Reef State Park : כתובת: 102601 Overseas Hwy, Key Largo, FL 33037, ארצות הברית Coral Reef Scuba: כתובת: 2784 Capital Cir NE # 2, Tallahassee, FL 32308, ארצות הברית