Chapter 7

Question 1

What is an aquatic life zone?

Answer 1

Aquatic biome

Question 2

What is salinity?

Answer 2

Amounts of various salts such as sodium chloride (NaCI) dissolved in a given volume of water

Question 3

What are the 2 types of aquatic life zones?

Answer 3

Saltwater/marine and freshwater

Question 4

Saltwater and freshwater systems cover what % of Earth’s surface?

Answer 4

71%

Question 5

Saltwater and freshwater systems contain what 4 major types of organisms?

Answer 5

1. Plankton
2. Nekton
3. Benthos
4. Decomposers

Question 6

Why is it difficult to count and manage populations in aquatic systems?

Answer 6

There is less pronounced and fixed physical boundaries than terrestrial eco systems.

Question 7

Are food chains/webs more complex in aquatic systems than terrestrial biomes?

Answer 7

Yes

Question 8

What is the euphotic zone?

Answer 8

Upper layer, where sunlight can penetrate and photosynthesis can happen

• Dissolved O2 levels are higher
• Dissolved CO2 levels are lower

Question 9

What is the mesopelagic zone?

Answer 9

Very little sunlight, 200m-1,000m below surface. Known as the “twilight zone” because sun can still be detected

Question 10

Oceans have which 2 zones?

Answer 10

Coastal zone and open sea

Question 11

What is the coastal zone?

Answer 11

Warm, nutrient-rich shallow water, and contains 90% of all marine species

Question 12

What is an estuary?

Answer 12

Partially enclosed area of coastal water where sea water mixes with freshwater and nutrients from rivers/streams

Question 13

What are coastal wetlands?

Answer 13

Land areas covered with water all or part of the year

Question 14

What is the dominant organism in mangrove forest swamps?

Answer 14

Trees that can grow in salt water - extensive roots above the water where they can get oxygen

Question 15

What is the intertidal zone?

Answer 15

Area of shoreline between low and high tide (not easy to live because of waves and high tides, changing levels of salinity)

Question 16

Why are coral reefs vulnerable?

Answer 16

They grow slowly and are disrupted easily

Question 17

What conditions do coral reefs thrive in?

Answer 17

Clear, warm, shallow water with constant high salinity, temperatures of 18-30 degrees Celsius.

Bleaching triggered by an increase of just 1 degree Celsius.

Question 18

What are the biggest threats to coral reefs?

Answer 18

Sediment runoff and other human activities

Question 19

What is the freshwater life zone?

Answer 19

Water with dissolved salt content below 1%

Question 20

What are lakes?

Answer 20

Large, natural freshwater bodies

Question 21

What is an epilimnion?

Answer 21

A layer of warm, well-oxygenated water

Question 22

What is a hypolimnion?

Answer 22

A layer with lower concentration of oxygen because it’s isolated from the surface

Question 23

What is fall turnover?

Answer 23

Surface water sinks to the bottom and brings nutrients up, and mixes oxygen down from the surface

Question 24

What is an oligotrophic lake?

Answer 24

New lake with generally small supply of nutrients, and deep with steep banks

Question 25

What is a eutrophic lake?

Answer 25

A lake with a large supply of nutrients

Question 26

What is surface water?

Answer 26

Precipitation that doesn’t sink into the ground and becomes runoff