Catastrophic Corals

1. Catastrophic Corals
By Anissa L. Boyers
** Planning elements. Do not orally cite these in your speech:
General Purpose: To create understanding
Specific Purpose: After listening to my speech, the audience will understand how coral
bleaching occurs and how humans have tried to regulate carbon emissions.
INTRODUCTION:
Attention Getter: Carbon emissions and the rising ocean temperatures are responsible for the
death of coral polyps, especially in the Great Barrier Reef.
Credibility statement: Because I am a biology major, I have found this topic thoroughly
interesting. The past several weeks, I have been doing extensive research about coral bleaching
and how the increase in temperature has been impacting aquatic organisms such as coral.
Benefit to audience/So what/WIIFM?: Some people may not see the relevance of helping coral
reefs; however, coral reefs are beneficial to the human population and are very important for
marine ecosystems.
Thesis: With increasing carbon emissions in the atmosphere, coral reefs are starting to become
bleached; however, there are preventative measures that humans can take to ensure that the
health of coral reefs does not diminish.
Preview: This afternoon I will first starting off by informing you about coral and how life is
dependent on coral reefs. Second, I will discuss what coral bleaching is and why it occurs.
Lastly, I will talk about the different actions that marine biologists are performing to reverse
coral bleaching.
Transition: First, I would like to talk about how coral functions within our ecosystem as well
as how it benefits us.
SPEECH BODY:
I. Coral is a marine organism that has an important niche in our ecosystem.
A. Coral polyps are small organisms that exist in colonies, which then form coral
reefs (Hampson, 2017).
1. Colonies of coral polyps produce calcium carbonate (CaCO3).
2. Calcium carbonate forms a hard skeleton for coral.
B. Coral and algae have a symbiotic relationship, meaning that both organisms
depend on each other to survive (James, 2018).

2. 1. Coral polyps consume algae, formally known as zooxanthellae (Torr,
2017).
a. Coral receives nutrients from the algae.
b. The zooxanthellae also give coral their color.
2. Algae also benefits from coral.
a. Algae also receives nutrients from the coral.
b. Coral provides algae a safe environment to live.
C. Humans and many aquatic organisms are dependent on coral reefs.
1. Coral reefs can be considered a keystone species (Reece, et al., 2017, p.
751).
a. This is because coral reefs have a large role in the ecosystem.
b. The death of coral reefs will have a great impact on the ecosystem
because many other species would not be able to survive.
2. More than 11,000 species depend on the Great Barrier Reef (Torr, 2017).
3. Humans are also dependent on coral reefs.
a. Coral reefs protect the coastlines to ensure that they do not erode
(Knowlton, 2001).
b. Humans and also depend on coral reefs through the food chain.
Transition: Next, we are going to talk about coral bleaching of the Great Barrier Reef and how
it occurs.
II. Coral bleaching is a phenomenon in which coral loses the algae that it consumes
(zooxanthellae).
A. The warming temperatures cause the coral to expel algae (Torr, 2017).
1. The coral loses the nutrients that it had obtained, and therefore starves
(James, 2018).
2. Because zooxanthellae also provide pigment in coral, the coral loses
its color and looks bleached (Torr, 2017).
a. Coral can survive if the polyps are able to reabsorb the algae.
b. If the coral cannot retain the algae, then it will eventually die due
to lack of nutrients.
B. Coral bleaching is majorly impacting the Great Barrier Reef, which is the
largest coral reef on earth (Torr, 2017).
1. The first coral bleaching phenomenon in the Great Barrier Reef took
place in 1998.
2. Since 1998, coral in the Great Barrier Reef has progressively getting
worse with a larger mortality.
3. Other serious bleaching events have occurred in 2002, 2006, 2008,
2011, and 2016 (Torr, 2017).
C. Coral bleaching occurs when the temperatures of the oceans rise (James,
2018).

3. 1. According to the national geographic in 2016, when the temperatures
rose in the Northern Management area of the Great Barrier Reef, 80
percent of the coral died.
2. Carbon dioxide reacts with water and forms carbonic acid (Torr,
2017).
a. This lowers the overall pH of the ocean and results in changes in
the ecosystem.
b. The coral and organisms that depend on the coral are more likely
to face adverse effects of this.
Transition: Finally, I would like to talk about how marine biologists and other people have
been working to improve coral bleaching in the Great Barrier Reef.
III. The coral bleaching in the Great Barrier Reef has already been pretty severe and
in most cases irreversible; however, there are still actions that have and can be
taken.
A. The Australian government has proposed actions in order to improve the water
quality (Torr, 2017).
Transition: At this time, I would like to recap.
SPEECH CONCLUSION:
Summary: The Great Barrier Reef is home to thousands of aquatic species that depend on the
coral reefs for protection. Because of the increase in the ocean temperatures, coral has started to
lose its algae and become bleached. This results in the coral to die which, makes the marine life
that rely on them more vulnerable. Although coral bleaching has already greatly impacted the
Great Barrier Reef, scientists believe that strict government regulations regarding the water
quality could make a difference.

4. References
Hampson, M. (2017, June 1). Scientists pinpoint how corals build their bony structures.
Retrieved from https://www.aaas.org/news/scientists-pinpoint-how-corals-build-their-bony-
structures
James, L. (2018, August 7). Half of the Great Barrier Reef is dead. National Geographic,
Retrieved from https://www.nationalgeographic.com
Knowlton, N. (2001, May 8). The future of coral reefs. National Academy of Sciences, 98(10)
5419-5425 Retrieved from http://www.nasonline.org/
Reece, J. B., et al. (2017). Campbell biology: concepts and connections. Boston, MA: Pearson
Education.
Torr, G. (2017). TO HOT to handle. Geographical (Geographical Magazine Ltd.), 83(1) 40.
Retrieved from https://www.geographical.magazine.co.uk/