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Our Oceans - The Health of Our Planet

Class 3: A City That Never Sleeps
Reading: "A City That Never Sleeps"
Activity: Paragraph on The Great Barrier Reef.

The Questions You Ask:
Why are reefs so crowded?

A City That Never Sleeps
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A City That Never Sleeps
In many ways A Coral reef is like a city: busy, crowded and colorful. The reef supplies food, protection and social life for the creatures that live there. Like in Cities, reef residents live at every possible level. Once an animal sets up housekeeping in one area, it rarely moves unless it is evicted by a new tenant. New housing is hard to find, coral reefs are more densely populated than the largest cities above the water.

Why are reefs so crowded? Tropical waters are crystal clear. They are clear because they contain so few plankton, minerals, decaying plants and other nutrients that plants and animals need to survive. A coral reef is like an oasis in the desert. It contains the only food and shelter for miles around. The fish, crabs, and other inhabitants contend for a limited supply of food. This supply consists of microscopic plants and animals carried into the reef by waves, mats of seaweed and other reef residents. Competition is fierce on the reef. Each reef resident has its own specialized habits, diet and coloring enabling it to carve out its own very special niche or position in the reef community.

One way reef dwellers have been able to share the limited resources of the reef is by maintaining different schedules. There are the day shift dwellers, the twilight shift dwellers, and the night shift dwellers.

Research Paragraph: The Great Barrier Reef.
Write what you remember about the Great Barrier Reef. Describe where it is and what sort of marine life lives there. Illustrate your paragraph.

VOCABULARY
Niche - a habitat supplying the factors necessary for the existence of an organism or species OR the ecological role of an organism in a community especially in regard to food consumption.