Introduction to OCEAN ZONES and Marine Organisms

Ms. Bridgeland

3 Major Ocean Zones

• Intertidal

• Neritic

• Open Ocean

Ocean Zones

1) Intertidal Zone: the shallow zone that begins at the highest high-tide line on land and stretches out to the point on the continental shelf that is the lowest tide

-the distance between the highest and lowest tides

2) Neritic Zone: extends from the lowest tide line out to the edge of the continental shelf

3) Open-ocean Zone: everything beyond the continental shelf that includes the deepest, darkest part of the ocean

Life in the Ocean

• Scientists classify marine (ocean) organisms based on two ways:

1) Where they live

2) How they move

3 Categories of Ocean Organisms

• Plankton – floating

• Nekton –free swimming

• Benthos –still or moving on the ocean floor

3 Categories of Ocean Organisms

1) Plankton: tiny algae and animals that float in the water and are carried by waves and currents.

• Algae plankton include geometrically shaped diatoms

• Animal plankton include tiny fish and microscopic crustaceans, such as copepods.

• There are a few larger plankton such as jellyfish.

Planktonic Algae Diatoms

Animal Plankton: Copepods

2) Nekton: free-swimming animals that can move throughout the water column.

*What are examples of Nekton?

2) Nekton

• Squid

• Most FISH

• Marine Mammals

What are Marine Mammals? (Nekton)

• Whales

• Seals

3) Benthos • Organisms that live on the ocean floor:

– Can stay stationary (still)• Sponges• Sea anemones

– Can move around from place to place• Crabs • Sea stars• Octopus • Lobsters

Plankton, Nekton, Benthos

Fun Fact

• Many plankton are algae

• Certain plankton, nekton, AND benthos eat other algae or organisms –what is this called?

Consumers• Animals that eat other organisms

Food Webs

• All of the feeding relationships that exist in a habitat

• PLANKTON is highly important in ocean food webs. All organisms depend either directly or indirectly on it– Why?

Plankton• Some of the largest sharks on earth feed

directly on tiny plankton

• The Earth’s largest animal (the Blue Whale) also feeds only on plankton (krill)