Ocean Acidification (College Board AP® Environmental Science): Exam Questions

What is coral bleaching?

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The world’s oceans play a crucial role in regulating the Earth's climate by absorbing large amounts of carbon dioxide (CO₂) from the atmosphere. However, due to the increasing concentration of CO₂ from human activities such as burning fossil fuels and deforestation, the oceans are becoming more acidic. This process is known as ocean acidification. The acidification of oceans can have harmful effects on marine life, particularly organisms that rely on calcium carbonate for their shells or skeletons, such as corals, mollusks, and some plankton species.

Corals, which rely on calcium carbonate to form their hard skeletons, are particularly vulnerable to ocean acidification. Additionally, corals have a relationship with microscopic algae called zooxanthellae. Zooxanthellae live inside the tissues of coral polyps and provide the corals with essential nutrients through photosynthesis. In return, the corals offer the zooxanthellae a protected environment and access to sunlight. This relationship is very sensitive to environmental changes.

Alongside ocean acidification, global warming is also affecting the oceans. Rising atmospheric temperatures are causing ocean waters to warm, leading to a variety of impacts. Warmer waters reduce the ability of the ocean to absorb CO₂, further exacerbating the problem of rising atmospheric CO₂ levels. Additionally, ocean warming can lead to the bleaching of coral reefs, as warmer temperatures stress corals and cause them to expel the zooxanthellae they rely on for energy. This loss of zooxanthellae deprives the coral of its main energy source and causes the corals to lose their vibrant colors, resulting in a phenomenon known as coral bleaching.

In combination, ocean acidification and warming pose significant threats to marine biodiversity, particularly in sensitive areas like coral reefs. 

Why is ocean acidification a threat to marine ecosystems?

Read the text below and answer the question:

The world’s oceans play a crucial role in regulating the Earth's climate by absorbing large amounts of carbon dioxide (CO₂) from the atmosphere. However, due to the increasing concentration of CO₂ from human activities such as burning fossil fuels and deforestation, the oceans are becoming more acidic. This process is known as ocean acidification. The acidification of oceans can have harmful effects on marine life, particularly organisms that rely on calcium carbonate for their shells or skeletons, such as corals, mollusks, and some plankton species.

Corals, which rely on calcium carbonate to form their hard skeletons, are particularly vulnerable to ocean acidification. Additionally, corals have a relationship with microscopic algae called zooxanthellae. Zooxanthellae live inside the tissues of coral polyps and provide the corals with essential nutrients through photosynthesis. In return, the corals offer the zooxanthellae a protected environment and access to sunlight. This relationship is very sensitive to environmental changes.

Alongside ocean acidification, global warming is also affecting the oceans. Rising atmospheric temperatures are causing ocean waters to warm, leading to a variety of impacts. Warmer waters reduce the ability of the ocean to absorb CO₂, further exacerbating the problem of rising atmospheric CO₂ levels. Additionally, ocean warming can lead to the bleaching of coral reefs, as warmer temperatures stress corals and cause them to expel the zooxanthellae they rely on for energy. This loss of zooxanthellae deprives the coral of its main energy source and causes the corals to lose their vibrant colors, resulting in a phenomenon known as coral bleaching.

In combination, ocean acidification and warming pose significant threats to marine biodiversity, particularly in sensitive areas like coral reefs. 

What happens to corals when the water temperature rises significantly?

Read the text below and answer the question:

The world’s oceans play a crucial role in regulating the Earth's climate by absorbing large amounts of carbon dioxide (CO₂) from the atmosphere. However, due to the increasing concentration of CO₂ from human activities such as burning fossil fuels and deforestation, the oceans are becoming more acidic. This process is known as ocean acidification. The acidification of oceans can have harmful effects on marine life, particularly organisms that rely on calcium carbonate for their shells or skeletons, such as corals, mollusks, and some plankton species.

Corals, which rely on calcium carbonate to form their hard skeletons, are particularly vulnerable to ocean acidification. Additionally, corals have a relationship with microscopic algae called zooxanthellae. Zooxanthellae live inside the tissues of coral polyps and provide the corals with essential nutrients through photosynthesis. In return, the corals offer the zooxanthellae a protected environment and access to sunlight. This relationship is very sensitive to environmental changes.

Alongside ocean acidification, global warming is also affecting the oceans. Rising atmospheric temperatures are causing ocean waters to warm, leading to a variety of impacts. Warmer waters reduce the ability of the ocean to absorb CO₂, further exacerbating the problem of rising atmospheric CO₂ levels. Additionally, ocean warming can lead to the bleaching of coral reefs, as warmer temperatures stress corals and cause them to expel the zooxanthellae they rely on for energy. This loss of zooxanthellae deprives the coral of its main energy source and causes the corals to lose their vibrant colors, resulting in a phenomenon known as coral bleaching.

In combination, ocean acidification and warming pose significant threats to marine biodiversity, particularly in sensitive areas like coral reefs. 

What type of relationship do corals have with zooxanthellae?

Read the text below and answer the question:

The world’s oceans play a crucial role in regulating the Earth's climate by absorbing large amounts of carbon dioxide (CO₂) from the atmosphere. However, due to the increasing concentration of CO₂ from human activities such as burning fossil fuels and deforestation, the oceans are becoming more acidic. This process is known as ocean acidification. The acidification of oceans can have harmful effects on marine life, particularly organisms that rely on calcium carbonate for their shells or skeletons, such as corals, mollusks, and some plankton species.

Corals, which rely on calcium carbonate to form their hard skeletons, are particularly vulnerable to ocean acidification. Additionally, corals have a relationship with microscopic algae called zooxanthellae. Zooxanthellae live inside the tissues of coral polyps and provide the corals with essential nutrients through photosynthesis. In return, the corals offer the zooxanthellae a protected environment and access to sunlight. This relationship is very sensitive to environmental changes.

Alongside ocean acidification, global warming is also affecting the oceans. Rising atmospheric temperatures are causing ocean waters to warm, leading to a variety of impacts. Warmer waters reduce the ability of the ocean to absorb CO₂, further exacerbating the problem of rising atmospheric CO₂ levels. Additionally, ocean warming can lead to the bleaching of coral reefs, as warmer temperatures stress corals and cause them to expel the zooxanthellae they rely on for energy. This loss of zooxanthellae deprives the coral of its main energy source and causes the corals to lose their vibrant colors, resulting in a phenomenon known as coral bleaching.

In combination, ocean acidification and warming pose significant threats to marine biodiversity, particularly in sensitive areas like coral reefs. 

Which type of feedback loop best describes the relationship between rising atmospheric temperatures and the ocean's ability to absorb CO₂?

Study the data below and answer the following question:

Based on the data above, what is the most likely impact of rising atmospheric CO₂ on ocean conditions?