This lesson introduces coral reefs, the animals that build them, and the partnership that helps many corals grow. Understanding the basic biology of reefs explains why they support so much marine life and why clear, sunlit water matters.
A coral reef is an underwater ecosystem built primarily by colonies of reef-building corals. Corals belong to class Anthozoa in the animal phylum Cnidaria, a group that also includes sea anemones and jellyfish. Unlike sea anemones, many reef-building corals secrete hard calcium carbonate skeletons that support and protect their bodies.
All flashcards
Reef-building coral
A cnidarian animal whose colony of polyps deposits calcium carbonate skeletons that help form reef structure.
Darwin's reef sequence
A proposed progression from fringing reef to barrier reef to atoll as a volcanic island subsides.
Darwin's paradox
The puzzle of highly productive coral reefs in tropical ocean waters that often contain few nutrients.
Ecosystem service of a reef
A benefit people receive from reefs, such as fisheries, tourism, or shoreline protection.
Marine protected area
A designated marine area intended to protect habitats and support responsible resource management.
Quiz questions
What is coral drowning?Answer: A reef becoming too deep for sufficient light when sea level rises or the seafloor subsides too quickly.
Which description best identifies an atoll?Answer: A roughly ring-shaped reef surrounding a lagoon, generally without a central island above sea level.
Which conditions are characteristic of the coral reef crest?Answer: Shallow water, abundant sunlight, and frequent exposure to wave action.
What helps resolve Darwin's paradox of productive reefs in nutrient-poor tropical waters?Answer: Efficient nutrient recycling, biological partnerships, and water movement that brings resources to reefs.
How can ocean acidification affect coral reefs?Answer: It can reduce coral calcification and increase dissolution of carbonate structures.
Based on the Wikipedia article Coral reef, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.