What is a kelp forest and which herbivore plays a critical role in shaping its structure?

• A. A kelp forest is a dense, multi-layered community of large brown algae in temperate coastal waters; sea urchins graze kelp and can create urchin barrens.
• B. A kelp forest is a freshwater algae community dominated by green algae.
• C. A kelp forest is a coral reef formed by calcium carbonate.
• D. A kelp forest is a seagrass meadow in tropical waters.

Answer: (A)