Unit 2 Test ESSAY QUESTION Coral Reefs. A series of coral reefs is located near a coastline. In 4+ sentences, construct an argument about how people can help prevent erosion to the coastline by protecting coral reefs.
Complete the sentences below AND CITE THIS SOURCE IN YOUR PARAGRAPH. Unit 2 Lesson 12, Pages 2, 5 and 6
Fill-in-the-blank Sentences – Copy/paste these with your answers on the test. Be sure to copy the Source, too! Cite your source: U2L12 PAGES 2, 5, and 6
Coral reefs are important in nature because __________. (Use U2L12 Page 2, 2nd paragraph.)
Scientists now know that reefs protect the coastline by __________. (Use U2L12 Page 5.)
Recent research has shown that pollution, global warming and sea levels affect reefs.
Pollution affects the reefs by __________. (Use U2L12 Page 6.)
Global warming affects the reefs by __________. (Use U2L12 Page 6.)
Rising sea levels affect the reefs by __________. (Use U2L12 Page 6.)
Here are some actions that people can take to protect coral reefs. (Then list the actions. Use U2L12 Page 6 for help.)
Cite your source: Source: Unit 2 Lesson 12, Pages 2, 5 and 6
UNIT2 LESSON 12 PAGE 2:
"Earth’s Evolution: Coral Reefs to New Life Forms The Great Barrier Reef near Australia is the largest coral reef system in the world. It stretches for 2,300 km (1429 mi.) over an area of 344,400 km2 (133,000 mi2). The Great Barrier Reef contains more than 3,000 separate reefs. It’s so large that it can be seen from space, the lighter blues of the shallow water contrasting with the dark blues of the deep ocean. Coral reefs such as the Great Barrier Reef are hotspots of biodiversity. In fact, thousands of different species—about 25 percent of all marine organisms—live in coral reef habitats. Coral reefs thrive in warm, shallow parts of the ocean, often near coastlines, in tropical and subtropical climates. They are composed of thousands of tiny coral polyps, which are small, sac-like animals. In most coral species, individual coral polyps live together in colonies. The polyps secrete calcium carbonate (limestone) that forms protective structures around their soft bodies. When the polyps die, the limestone skeletons remain, forming the hard-coral reef. Living corals exist on the top layer of the reef. Colonies can live for hundreds or thousands of years. Coevolution occurs when the interaction of two or more species cause a change in those species' evolution. So how did coral reefs coevolve with other organisms? How do coral reefs enable the evolution of new life forms? How do coral reefs affect erosion and deposition along coastlines? How do coral reefs benefit humans, and what threats do humans pose for coral reefs?"
PAGE 5:
"How Coral Reefs Affect Erosion and Deposition Because coral reefs form in shallow ocean water, they absorb much of the energy of waves coming in to shore from deeper parts of the ocean. Coral reefs also protect coastlines during storms, such as tropical cyclones. They preserve stands of mangroves and seagrass beds. In the geologic past, as coral reefs formed they changed the patterns of erosion and deposition along coastlines. They protected coastlines from waves that would otherwise erode them and carry floodwaters inland. They prevented water from carrying away eroded sediment, which often formed sandbars or was deposited elsewhere along the coastline. View the video and take notes on the benefits of coral reefs. The Benefits of Coral Reef Transcript
An image shows a sandy beach. Footprints are visible in the sand, and a wave retreats back into the water.
TEENAGER: Mom, look what the tide just brought in! A piece of coral!
Two hands hold up a piece of coral.
MOM: Wow! You know, coral has been around for over 450 million years.
TEENAGER: That was 200 million years before the dinosaurs.
MOM: Yes, and coral played an important role in the evolution of sea life and life on land.
An image shows several small fragments of coral resting on the sand as water washes over them.
TEENAGER: Really? How does coral play such a big role in evolution? It just looks like a small piece of rock.
An image of several polyps is shown. They have sac-like bodies and tentacles that resemble flower petals around their mouth openings. The word polyp appears on a label over the image.
MOM: One piece of coral can be the home to hundreds of tiny polyps. Polyps are living things that secrete calcium carbonate to make the coral structure that you are holding.
An image shows an underwater view of a coral reef. A large formation of coral is shown in the foreground with more coral in the background. A school of small fish swim around the coral.
TEENAGER: That’s right. I read that polyps cement themselves to the ocean floor and create large colonies called coral reefs. Some reefs expand to an area of more than 130,000 miles.
An image of a beach is shown. Clear water meets the shoreline which is dotted with palm and mangrove trees. The image shifts to show more of the water, and a coral reef becomes visible just beneath the water’s surface. The words protected from erosion appear on a label over the image.
MOM: Did you know that reefs act as a barrier against waves by lessening the waves’ momentum? With the force of the wave decreased, shorelines are protected from erosion. Gentler waters also provide a calmer habitat for plants and animals to grow and evolve.
An image shows an underwater view of a coral reef. Several types of coral grow on top of each other in the shallow water. The words warmer temperatures appear on a label over the image.
TEENAGER: I learned that the vertical expansion of reefs lessens the depth of the water. With shallower waters, water temperatures are warmer, which allows plant and animal species to thrive.
An image shows another underwater view of a coral reef. This image shows a close-up of a coral reef with four different species of fish swimming around the coral growth. The words remove carbon dioxide and provide food and shelter appear on labels over the image.
MOM: But did you know that coral reefs remove carbon dioxide from the sea and provide food and shelter for millions of species?
TEENAGER: Come on, Mom! Of course I knew that.
An image shows an underwater view of a coral reef that has died. There is no growth, only coral skeletons. There are no fish, and the water is murky.
MOM: Unfortunately, coral reefs are currently dying, which could cause several problems ranging from seashore erosion to tsunamis to the loss of different species. This dead piece of coral you found might be from coral reef deterioration.
An image shows a set of goggles and a snorkel resting on a sandy beach.
TEENAGER: Well then, we should get our snorkeling gear on and go admire these coral reefs that we’ve been talking so much about!"
PAGE 6:
"Threats to Coral Reefs Today, coral reefs face many threats. Climate change is the most pressing. Healthy reef-building corals need a certain intensity of sunlight so the algae that live in their tissues can photosynthesize. Corals also need for the water in which they live to be a certain depth and temperature. Climate change, triggered by the burning of fossil fuels, is warming Earth. Climate change is melting ice sheets, glaciers, and the polar ice caps, causing sea levels to rise and putting coral reefs deeper under water. This deprives the zooxanthellae of sunlight. It also reduces the protective effect that coral reefs have on coastlines, exposing them to erosion, deposition, and flooding. Climate change also causes higher ocean temperatures and a phenomenon called bleaching. When the temperature of ocean is too high, the colorful zooxanthellae leave the corals. (It is unclear whether the algae are expelled or leave on their own.) The corals lose an important source of nutrients. They become translucent and their white calcium carbonate skeletons are visible. These corals look white or “bleached.” They aren’t dead, but they are more susceptible to disease. Corals cannot live for long without the zooxanthellae. Other human activities can stress or kill coral reefs. When insecticides, herbicides, fertilizers, and industrials pollutants seep into the water, they poison corals. Divers accidentally damage reefs or purposefully break off coral for souvenirs. Development produces sediments that pollute water, smothering coral reefs or depriving them of sunlight. Overfishing also depletes the ecosystem. Natural processes can also harm coral reefs. Tsunami waves, for example, can break coral reefs and drag sediment with them when they recede back into the ocean. The sediment can smother coral reefs."
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Coral reefs are important in nature because they serve as hotspots of biodiversity, supporting about 25 percent of all marine organisms and providing crucial habitats for numerous species (U2L12 Page 2, 2nd paragraph). Scientists now know that reefs protect the coastline by absorbing wave energy, thereby reducing erosion and preserving coastal ecosystems like mangroves and seagrass beds (U2L12 Page 5). Pollution affects the reefs by introducing harmful chemicals, such as insecticides and fertilizers, that poison the corals and disrupt their ecosystems (U2L12 Page 6). Additionally, global warming affects the reefs by increasing water temperatures, which leads to coral bleaching, making them more susceptible to disease and reducing their ecological function (U2L12 Page 6). Rising sea levels affect the reefs by submerging them further underwater, diminishing their capacity to protect the coastline from erosion (U2L12 Page 6).
Here are some actions that people can take to protect coral reefs: reduce pollution by using fewer chemicals, participate in coastal clean-ups, support sustainable fishing practices, and advocate for policies that address climate change. By protecting coral reefs, we not only preserve marine biodiversity but also safeguard our coastlines from erosion and mitigate the impacts of storms.
Cite your source: Source: Unit 2 Lesson 12, Pages 2, 5 and 6.
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