Zoning In Why is Earth called the Blue

Zoning In Why is Earth called the Blue Planet? It’s because the world’s five oceans (the Pacific, Atlantic, Indian, Southern and Arctic) cover two thirds of its surface. The oceans support a wide variety of life. But not everything can live everywhere. From top to bottom, there are different zones in the ocean. Each zone is defined by such things as sunlight, temperature, and water pressure. Sunlit Zone 0 -650 ft Twilight Zone 650 -3, 300 ft Dark Zone 3, 300 -13, 000 ft Abyss 13, 000 -20, 000 ft Trenches over 20, 000 ft

Surface Sunlight Sunlit Zone (0 -650 ft) Coral reefs support an amazing amount of life. However, they are only found in the sunlit zone. That’s because the sunlit zone gets enough light for photosynthesis to occur. Why is this important? Sunlight allows algae to grow. Living coral need algae so they can produce the hard skeletons that protect their soft bodies. The Great Barrier Reef in Australia is over 1, 200 miles long.

The Twilight Zone Large eye helps spot prey in the dark The Twilight Zone (660 -3, 300 ft) Dive below 650 feet and things really begin to change. Welcome to the twilight zone! Not much light gets to this zone so the animals that live here have special adaptations. This hatchet fish has light-producing organs in its mouth to attract prey. Light organs under tale Deep-sea hatchet fish It also has light organs along its belly and tail so when the fish is viewed from underneath, it can better blend in with the brighter surface water above it. Light organs on belly Light patches in the mouth help guide prey right into its jaws

Darkness Descends Dark Zone (3, 300 -13, 000 ft) The dark zone begins below 3, 300 feet. There is no light in this zone, temperatures are cold, and food is scarce. Yet creatures like this deep-sea anglerfish still survive. Bacteria that glow in the dark live in the structure above the fish’s mouth. The anglerfish uses this structure like a fishing pole to lure prey into its huge jaws. After swallowing its prey, the fish’s stomach stretches to hold the whole meal. Deep-sea anglerfish before meal Lure has bacteria that can light up Teeth bend backward to keep prey from escaping After meal Stretchy stomach allows anglerfish to eat huge meals

Into the Abyss (13, 000 -20, 000 ft) Below the dark zone is the abyss. Here, the water temperature is almost freezing and soft clays and mud-like ooze cover the ocean floor. Can anything exist in such a hostile environment? The deep-sea cucumber does quite well by feeding on the remains of dead animals and plants that have sunk to the ocean floor. Deep-sea cucumber Extra long tube feet for walking along soft ocean floor

Hot Water Hideouts Plumes of hot, sulfur-rich water rise from vents Trenches (over 20, 000 ft) Deep water trenches and canyons drop below the ocean floor to form the deepest zone in the ocean. The water pressure in these places can be an incredible 8 tons per square inch. However, even in the trenches, scientists have found life. Gigantic plates that make up the Earth’s crust move apart to form cracks, or vents, in the trenches. Hot, mineral-rich water gushes up through these vents and allows bacteria to grow. This provides a food source for strange animals, like tube worms, to grow. Tube worms can grow to 10 feet long