Oceans

Marine Environments• Environment: The air, water, minerals, organisms, and all

other external factors surrounding and affecting a given organism at any time.

• Life in the ocean is affected by water depth and the amount of sunlight that passes into the water

• Major Environmental Zones:

1. Intertidal Zone

2. Neritic Zone

3. Oceanic Zone

4. Benthic Zone

Marine EnvironmentsIntertidal Zone

Neritic Zone Oceanic Zone

Benthic Zone

Marine EnvironmentsA B C

D

CONTINENTAL SHELF

Intertidal Zone• Where ocean meets the land

• Exposed to air part of day

• Waves constantly crashing

• Covered at high tide, exposed at low tide

• Mudflats: worms and crabs

• Sandy Beaches: worms, clams, crabs, plankton

• Rocky Shores: sea stars

Neritic Zone

• Water becomes deeper

• Ocean floor starts to slope downward

• Water warm and gets a lot of sunlight

• Many plants/animals live here: Ex: corals, sponges,

seaweeds, sea turtles, fishes, dolphinshttp://player.discoveryeducation.com/index.cfm?guidAssetId=302d9cce-c1f8-4a

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Oceanic Zone• Sea floor drops sharply

• Deep water of open ocean in this zone

• Plankton can be found near the water’s surface

• Fishes, whales, sharks live here

• Some animals live in very deep water and get food from material that sinks down from ocean surface

Benthic Zone• Ocean floor

• Deepest parts of this zone do not get sunlight and get very cold

• Fishes, worms, sea urchins, and crabs have special adaptations to live here

• Get food from material that sinks down from above

• Other organisms, like bacteria, get energy from chemicals that escape from thermal vents on ocean floor (vents form at cracks in Earth’s crust)– CHEMOSYNTHESIS http://player.discoveryeducation.com/index.cfm?guidAssetId=35d15d0e-055a-40e1-8022-2be6491a7254&blnF

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Marine EcosystemsEcosystem: all the living/nonliving parts of an

environment that live in the same habitat

The Earth’s Marine Ecosystems:• Intertidal Areas• Coral Reefs• Estuaries• Mangrove Swamps• The Sargasso Sea• Polar Ice

Intertidal Organisms• Must be able to live in and out of

the water

• Organisms in this zone have adapted to keep from being washed away by crashing waves

• Holdfasts – root-like structures attach to rocks

• Other organisms attach to the rock by releasing a special glue

• Sea grasses, snails, herons, clams, crabs, and conchs are all found in the intertidal zone

Coral Reefs• Found in warm, shallow

waters

• Made of small animals called corals

• Live in large groups

• Corals die and leave their skeletons behind

• New corals grow on these remains

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Estuaries• Area where fresh water

from streams and rivers spills into oceans

• In estuaries, fresh water and salt water constantly mixing

• Tides help mix fresh and salt water creating an environment that is very rich in nutrients so area is very productive ecosystem

• NC estuaries are being polluted by urban development and agricultural runoff, which kill fish and plants

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Why estuaries are so important?

• Rich in nutrients from both land and ocean – plants and soils in an estuary trap nutrients

and help break down waste and pollution– also support large numbers of plankton

• Plankton provides food for larger animals, like fish

• Dolphins, manatees, seals and other mammals feed on fish and plants in estuaries

• Birds, like the egret or heron, feed on fish and invertebrates (worms) that live in estuaries

• Estuaries also provide protected area for migratory birds to rest and breed

• Acts like a nursery for many juvenile organisms– Especially your seafood!

Mangrove Swamps• Swamps located along

coast of warm or tropical areas

• Mangrove trees grow here and help prevent erosion of coastline… especially during storms

• Breeding and feeding area for many different organisms

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The Sargasso Sea• Found in the middle of

Atlantic Ocean

• Contains floating rafts of algae called sargassum

• Many animals that live in the Sargasso Sea are the same color as the sargassum, which helps them hide from predators

• Weedline

Polar Ice• Found in Arctic Ocean and in the

ocean around Antarctica – N/S poles

• Rich in nutrients which support large numbers of plankton

• Plankton forms the basis of the Arctic and Antarctic food webs – many fishes, birds and mammals rely on it for food

• Beluga whales and penguins also live in these areas

Beluga Whale

There are 17 species of penguins, and five of them live in and around Antarctica.

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Life in the Ocean• Can a cow live on the ice in Alaska?• No – polar bears live in this unique place.

• Just like a cow and a polar bear live in different places on Earth, an octopus and a dolphin live in different parts of the ocean.

• Studying life in the oceans is very complicated because they are so large.

• There are still many organisms we don’t know of or know little about.

• To make things easier, scientists classify marine organisms into three main groups.

Three Groups of Marine Life

• Organisms are placed in groups based on where they live and how they move

– Plankton

– Nekton

– Benthos

PLANKTON• Organisms that float or

drift freely near ocean’s surface

• Microscopic• Food for many organisms

– Phytoplankton plant like – provides most of Earth’s oxygen

– Zooplankton animal like

NEKTON

• Swim actively in open ocean – mammals like whales,

dolphins, and sea lions– fish

BENTHOS

• Live on or in ocean floor

• Crabs, starfish, worms, coral, sponges, seaweed, and clams

Food Web vs. Food Chain ?

Do terrestrial and aquatic food webs ever cross?

Example?

Interconnected Food Webs• Aquatic and Terrestrial

• They interconnect in an estuary or intertidal zone

• Animals like frogs and birds live in water and on land– A frog can eat a fly on land and be eaten by a

snake in the water

• Microbes – recycle nutrients/wastes of other organisms, including nitrogen from sewage

• Humans are top consumers fishing/agricultural industries

Estuarine Plants & Animals

Make Your Own Food Web• Choose 10 organisms: estuaries/intertidal zones

• Create a food web for your ten organisms

• The web must overlap between land/water

• Label/draw each organism

• Draw arrows to show the web and how the animals are connected

• Color your food web