Zones - Day 1 Lesson

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

Surface Sunlight Surface Sunlight Sunlit Zone (0 650 ft) The Great Barrier Reef in Australia is over Coral reefs support an amazing 1,200 miles long. 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 Twilight Zone The Twilight Zone Large eye Twilight Zone (660 3,300 ft) helps spot prey in Dive below 650 feet and the dark things really begin to change. Welcome to the twilight zone! Not much light gets to Light organs this zone so the animals under tale that live here have special adaptations. This hatchet Deep-sea hatchet fish fish has light-producing organs in its mouth to attract prey. It also has light organs along its belly Light organs on belly and tail so when the fish is viewed from underneath, it can better blend in with Light patches in the mouth help the brighter surface water above it. guide prey right into its jaws

Darkness Descends Lure has Darkness Descends bacteria Dark Zone (3,300 13,000 ft) that can Deep-sea anglerfish light up before meal The dark zone begins below 3,300 feet. There is no light Teeth bend backward to in this zone, temperatures are keep prey from escaping cold, and food is scarce. Yet creatures like this deep-sea After meal anglerfish still survive. Stretchy stomach Bacteria that glow allows anglerfish in the dark live in to eat huge meals 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.

Into the Abyss Into the Abyss Abyss (13,000 20,000 ft) Deep-sea cucumber Below the dark zone Extra long tube feet for walking is the abyss. Here, the along soft ocean floor 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.

Hot Water Hideouts Plumes of hot, Hot Water Hideouts sulfur-rich water Tube worms rise from vents can grow to 10 feet long 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.