Chapter 4 Lesson 4: Ocean Ecosystems

freshwater

Water that does not contain salt or is very low in salt content.

plankton

Small organisms that drift freely in the water and are unable to swim.

nekton

Larger organisms that are active swimmers in a body of water, such as fish.

benthos

Organisms that live on the bottom of a body of water, such as oysters.

running-water ecosystem

A freshwater ecosystem with moving water, such as a river, stream, or brook.

standing-water ecosystem

A freshwater ecosystem with still water, such as a lake or a pond.

freshwater wetlands

Regions that are wet for most of the year and found between land and water.

shallow-water zone

The area along the shore of a lake where most of the organisms live.

open-water zone

The area of a lake away from the shore where plankton float near the surface.

bottom zone

The deep area of a lake that has very little light and little oxygen.

intertidal zone

The shallowest part of the ocean that is covered and uncovered by the tides.

neritic zone

The part of the ocean where sunlight reaches the bottom and many producers grow.

bathyal zone

The ocean zone that is home to many consumers but very few producers.

abyssal zone

The deepest part of the ocean that is very cold and completely dark.

estuary

The unique ecosystem where freshwater from a river feeds into salt water.

salt marshes

Boggy areas in estuaries that help filter water and soak up excess storm water.

abiotic factors

Nonliving things like light and salt that affect which organisms survive in water.

diatoms

A type of plankton that acts as a producer by making its own food.

scavengers

Organisms that feed on dead material that floats down to the bottom of water.

photosynthesis

The process that producers use to release oxygen and make food using sunlight.

adaptations

Special features that help an organism survive in a specific type of water environment.

dissolved oxygen

The oxygen found in water that is used by aquatic organisms to breathe.

hydrothermal vents

Cracks in the deep ocean floor that release heat and minerals into the water.

tides

The daily rise and fall of the ocean level caused by the moon's gravity.

producers

Organisms like algae and plants that use sunlight to make their own food.

consumers

Organisms that must eat other living things to get the energy they need.

rivers

Large bodies of running water that flow across land and into the ocean.

lakes

Large bodies of standing water that are divided into three main zones.

marshes

A type of wetland that is often covered with grasses and marsh plants.

swamps

A type of wetland that is often filled with water-soaked soil and trees.

kelp forests

Important habitats in the neritic zone that provide food and shelter for sea life.

coral reefs

Structures in the neritic zone that are home to many different ocean organisms.

nutrients

Substances washed into the water from land that help organisms grow and survive.

currents

Fast-moving flows of water that organisms must adapt to in rivers and streams.

decomposers

Organisms that get energy by breaking down dead material on the ocean floor.

twilight zone

The upper part of the bathyal zone where very little sunlight can reach.

marine mammals

Animals like whales and seals that live in the water but breathe air.

high tide

The time of day when the intertidal zone is completely covered by the ocean.

low tide

The time of day when organisms in the intertidal zone are exposed to air.

dissolved salt

An abiotic factor that is high in the ocean but very low in freshwater.

bogs

A type of wetland that is wet for most of the year and contains moss.

sunlight

The main energy source that producers in the shallow water use to grow.

tube worms

Organisms that live near hydrothermal vents in the cold and dark abyssal zone.

gravity

The force from the moon that causes the water in oceans to move.

algae

A type of producer that is common in slow-moving water and open-water zones.

filtration

The process by which salt marsh plants remove pollution and waste from river water.

ocean water

Type of water that covers about ninety-seven percent of the surface of the Earth.

fast-moving water

Freshwater that contains more oxygen because air mixes in as the water flows.

slow-moving water

Freshwater that has less oxygen and is more dependent on producers like algae.

oceanic zone

The deep part of the ocean that includes the bathyal and abyssal zones.