After the Reef Turns White

• ○A. Reef recovery mainly depends on algae returning and restoring the colors of surviving corals.
• ○B. Reef recovery follows a predictable sequence that researchers can track by counting young corals.
• ○C. Reef recovery involves survival and new growth, with progress shaped by local conditions and heat.
• ○D. Reef recovery depends on nearby colonies supplying enough larvae to cover empty surfaces.

These algae provide much of the corals' food through photosynthesis and contribute to their color.If stressful conditions ease soon enough, surviving corals can regain algae and rebuild their energy supplies.Researchers look beyond color when checking a reef's progress.Different reefs can follow different paths, depending on damage, surviving coral, and local conditions.

• ○A. Bleached corals may survive, but restored color does not show complete recovery.
• ○B. Bleached corals regain their energy before algae return to their tissues.
• ○C. Corals produce more young while recovering to replace those lost to heat.
• ○D. Corals that survive bleaching return quickly to their earlier growth rates.

A bleached coral is not necessarily dead.During bleaching, however, they have less food available.If the stress continues, they may die.Even corals that survive may grow more slowly or produce fewer young for a time.

• ○A. It establishes that distant reefs supply most of the young corals needed for recovery.
• ○B. It explains why coral larvae recover more quickly than surviving adult colonies.
• ○C. It shows that larvae settle successfully once they arrive at a damaged reef.
• ○D. It adds that recovery includes new colonies, not just improvements in surviving corals.

• ○A. Coral larvae travel through the water before they settle.
• ○B. Larvae settling on suitable surfaces can grow into new colonies.
• ○C. Some coral larvae arrive from reefs farther away.
• ○D. Surviving corals nearby can supply larvae to a reef.

• ○A. Local protection can improve conditions but cannot prevent damage from repeated warming.
• ○B. Local protection benefits mature colonies but offers little help to young corals.
• ○C. Local protection must wait until young colonies mature and cover the bare areas.
• ○D. Local protection can cool a reef but cannot provide surfaces where larvae settle.

Large seaweeds can take over space where coral might settle.Plant-eating fish help by grazing on these seaweeds.Local protection cannot remove the danger of repeated ocean warming.On a recovering reef, new coral colonies may be growing even while other areas remain bare.

• ○A. Heat can cause corals to bleach. Once their color returns, recovery is nearly complete, and researchers mainly need to check whether young colonies have covered the remaining bare surfaces.
• ○B. Corals depend on tiny algae for food and color. Researchers study these fascinating partnerships, and everyone should support reef protection because colorful reefs are among the ocean's most beautiful places.
• ○C. Corals can recover after bleaching through renewed algae partnerships and new colonies. Recovery takes time, depends on suitable conditions, and can be interrupted by heat; researchers track several signs of progress.
• ○D. Coral larvae travel from nearby and distant reefs before settling on hard surfaces. Grazing fish clear seaweed, sediment can cover surfaces, and researchers count the small colonies that grow on reefs.

• ○A. Researchers compare their observations of a reef over time.
• ○B. Reefs follow different paths depending on their local conditions.
• ○C. Researchers distinguish brief improvement from a broader recovery.
• ○D. Researchers record coral cover, small colonies, and kinds of coral.

• ○A. Grazing fish are the most valuable animals because they save space for young corals.
• ○B. Grazing fish eat seaweeds that can occupy space where young corals might settle.
• ○C. Grazing fish restore damaged reefs by preventing the ocean water from becoming warmer.
• ○D. Grazing fish deserve protection because their work is more important than other reef processes.