Ocean Habitats: Light and Dark Zones (video)

Science 8

  1. What is a habitat?
  1. What percentage of the Earth is covered by ocean? ______
  1. Ocean water contains minerals such as ______and gases such as ______, nitrogen and carbon dioxide,which are necessary to the survival of ocean organisms.
  1. Describe six ways light and dark zones of the oceanhabitat are different.
  1. What are adaptations?
  1. Describe some adaptations of fish.
  1. Describe the light zone.
  1. Where are most living things found in the ocean?
  1. What is plankton?
  1. How do large animals like whales survive on plankton?
  1. Describe the darkzone.
  1. If algae cannot grow in the dark, what food is available in the dark zone?
  1. Describe some adaptations of living things found in the dark zone.

Ocean Habitats: Light and Dark Zones (video)

Science 8

  1. A habitat is a place where plants andanimals naturally live, which provides food, water, andshelter.
  2. Theocean is a salty, watery home to over 250,000 kinds of living things. It covers approximately 70% of the Earth.
  3. Ocean water contains minerals such as salt and gases such as oxygen, nitrogen and carbon dioxide,which are necessary to the survival of ocean organisms.
  4. The light and dark zones of the oceanhabitat are different in at least six ways:

movement of the water / amount of sunlight / temperature
pressure / availability of food / salinity of the water.
  1. Adaptations are differences among living things that help them survive, to get food and stay safe.
  2. Fish have adapted in many ways tosurvive in their habitats. They have different size and shape,consume(drink) a lot of water, breathe through gills, have internal ears, secrete mucous, andsome are camouflaged.
  3. The light zone the sunlight reaches down about 100-200meters below the water. The light zone is divided into two parts, the continentalshelf and the open ocean.
  4. Most of the ocean life is on the continental shelf. Rivers and currents provide nutrients to kelp forests and sea grassmeadows on the continental shelf. The open ocean containsless food than the shelf waters so there are fewer living things.
  5. Tiny algae and small animals that eat algae are called plankton.
  6. Blue whales have a special adaptation in their mouths called baleen, which allows them to eat plankton.
  7. The darkzone is a harsh environment, having no sunlight, little food,cold water, and extreme water pressure.
  8. The mid-water layer of the dark zone is located where thecontinental shelf ends and the land of the continental slopeplummets down. There is very little light in this layer. Manyof the animals here feed off of the dead organic materialthat washes down the continental slope from the lightzone.
  9. Dark zone creatures have made specialadaptations in order to live in their harsh environment. Some fish, like the lantern fish and the flashlight fish, maketheir own light through chemical reactions. Many fishmigrate up to the light zone at night in order to hunt andfeed.