Abiotic Factors
Aquatic Organisms
Freshwater Ecosystems
Coastal Ecosystems
Ocean Ecosystems
100

The amount of dissolved salt in water.

What is salinity?*

100

Small, free-floating organisms that include phytoplankton and zooplankton.

What is plankton?*

100

Freshwater salinity ranges between these values.

What is 0–0.5 ppt?*

100

A partially enclosed body of water where rivers meet the sea.

What is an estuary?*

100

The zone is alternately exposed and submerged due to tides.  

What is the intertidal zone?*

200

This abiotic factor is highest in cold, turbulent water.

What is dissolved oxygen?*

200

Large, independent swimmers like fish, turtles, and whales.

What are nekton?*

200

The warm, shallow, sunlit zone near shore in a lake or pond.

What is the littoral zone?*

200

The landform created at a river’s mouth by deposited sediment.

What is a delta?*

200

The type of tide with the greatest tidal range, occurring during new and full moons.

What are spring tides?*

300

The measure of water cloudiness due to soil runoff or algae bloom.

What is turbidity?*

300

Bottom-dwelling organisms with little to no movement.

What are benthos?*

300

Lakes with low nutrient levels and clear water.  

What are oligotrophic lakes?*

300

These forests contain trees with roots that filter salt and protect coasts from waves.

What are mangrove forests?*

300

Ecosystems built on coral polyps’ calcium carbonate skeletons.

What are coral reefs?*

400

This abiotic factor decreases as water depth increases.

What is the availability of sunlight?*

400

Organisms that break down dead material and recycle nutrients.

What are decomposers?*

400

The part of a river where dissolved oxygen is highest and nutrients are lowest.  

What are the headwaters?*

400

Wetlands dominated by grasses, often found in tidal flats.

What are salt marshes?*

400

Deep-sea organisms that produce light through chemical reactions.

What is bioluminescence?*

500

Ocean water has a pH of about 8.1 due to this ion.  

What are carbonate ions?*

500

Identify one abiotic factor that influences plankton abundance.  

What is availability of sunlight (or dissolved oxygen, nutrients, etc.)?*

500

Name two adaptations of wetland plants.

What are floating tissues, carnivorous traps, or emergent tissues with air spaces?*

500

How much wave energy can mangrove forests dissipate?  

What is up to 90%?*

500

The process by which organisms at hydrothermal vents make food using chemicals.

What is chemosynthesis?*