Main Idea #1: Ocean life changes as you move from the shoreline out to open ocean Main Idea #2: Ocean life changes as you move from the surface to the deep waters Main Idea #3: Feeding relationships in the ocean can be connected to relationships on land

Ocean Zones Oceanic life is divided into two major zones –the benthic zone (the sea floor) Means “bottom” mostly made up of bottom dwellers which get most of their food from dead and decaying organisms –the pelagic zone (the open ocean) The pelagic environment is further divided based on water depth and sunlight.

Ocean life changes as you move from the shoreline out to open ocean

Life at the Shore Neritic zone: the first 200 meters (656 feet) of water, which includes the seashore and goes to the edge of the continental shelf. Intertidal zone: the area along a coastline that is underwater at high tide and above the water at low tide. –Organisms in the intertidal zone needs to be able to survive extreme conditions Low tide: no water, exposure to heat and bright sunlight. High tide: organisms pounded by waves.

Life at the Coast What’s the name of the habitat where saltwater meets freshwater? estuary Organisms thrive on nutrients washed in by rivers Still water and grasses offer protection for eggs and small fish Wetlands can form at the edges of estuaries. Two kinds of coastal wetlands: Salt Marshes Mangrove forests

Salt Marshes Occur in cooler areas In U.S. located on both Atlantic and Pacific coasts Keep the shoreline from washing away –Rivers carry soil/sediment to marsh, which supports thick grasses; roots hold the muddy bottom in place Filter water Home to many organisms

Mangrove Forests Occur in tropical regions In U.S. found along coast of FL Contain thick groups of mangrove trees Protects shorelines from washing away –Strong roots to brace against storms, waves Home to many organisms

Ocean life changes as you move from the surface to the deep waters

Coral Reefs Located in tropical areas Corals are polyps (similar to sea anemones) that build up limestone around their bodies New coral grow on top of old coral Algae live in individual coral –Corals rely on algae to make food (photosynthesis) –Algae depends on coral for some nutrients and shelter Contains a variety of life

Kelp Forests Located in cooler areas In sunlit areas of ocean, kelp attach to rock/ocean floor and grow as tall as 40 meters Provide habitat for many animals

Life in the Deep Cold, dark No photosynthesis, so organisms rely on food drifting down from top

Hydrothermal Vents Geyser on the seafloor Discovered in 1977 Spews super-hot, mineral-rich water Once thought to have very little life, but actually teeming with life Along mid-ocean ridge saltwater seeps into cracks, is heated, and rushes up (400ºC) Chimneys are at the top of some vents (formed from metals that precipitate out when hot water meets cold ocean water)

Organisms In the Ocean Classified by the way they move and where they live Plankton: microscopic algae and animals that float at surface of the water Nekton: free-swimming animals that can move throughout the water column. Benthos: organisms that inhabit the ocean floor which may move (like crabs) or stay in one place (like sponges)

Food Chains and Webs Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water (also called an autotroph) Animals cannot make their own food so they must eat plants and/or other animals. They are called consumers (also called a heterotroph). There are three groups of consumers. Animals that eat ONLY PLANTS are called herbivores (or primary consumers). Animals that eat OTHER ANIMALS are called carnivores. –carnivores that eat herbivores are called secondary consumers –carnivores that eat other carnivores are called tertiary consumers Animals and people who eat BOTH animals and plants are called omnivores. Then there are decomposers (bacteria and fungi) which feed on decaying matter.