Complex Ecosystem Transformations Quick Check What causes coral bleaching?(1 point) High water temperatures bol coral polyps, causing them to turn white in color. Water acidity and high water temperatures make coral polyps more prone to infection, causing them to turn white in color. Water acidity causes coral polyps to lose their photosynthetic abilities, causing them to turn white in color. High water temperatures and water acidity cause coral polyps to expel algae.causing them to turn white in color.

## Step 1
Coral bleaching is a phenomenon that occurs when corals lose their vibrant colors and turn white. This happens when the algae, known as zooxanthellae, which live in the coral's tissues and provide them with essential nutrients, are expelled. This expulsion is usually due to stress factors such as changes in water temperature and acidity.

## Step 2
The first option suggests that high water temperatures cause coral polyps to turn white. While temperature changes can stress corals, this option does not mention the expulsion of algae, which is the primary cause of bleaching.

## Step 3
The second option combines water acidity and high temperatures, suggesting these factors make coral polyps more prone to infection. However, the primary cause of bleaching is not infection but the expulsion of algae due to stress.

## Step 4
The third option incorrectly attributes the loss of photosynthetic abilities to water acidity. While water acidity can stress corals, it is not the direct cause of bleaching.

## Step 5
The fourth option correctly identifies that both high water temperatures and water acidity can stress corals to the point where they expel their resident algae, leading to bleaching.