9. Freshwater Ecosystems

Question 1

Name the two most common freshwater ecosystems?

Answer 1

Lakes and rivers

Question 2

What are the challenges with living in fresh water habitats?

Answer 2

Density, flow, velocity, light, temperature, dissolved oxygen, carbon dioxide, pH, nutrient

Question 3

What percentage of water does fresh water make up

Answer 3

3%

Question 4

What % if fresh water is accessible?

Answer 4

1%

Question 5

How does density vary?

Answer 5

With temperature and salinity

Question 6

What is viscosity?

Answer 6

Resistance of a fluid to shear stress or drag

Question 7

What happens when as animal gets larger?

Answer 7

They experience more pressure

Question 8

What happens to a small animals in water?

Answer 8

Drag and viscosity dominate

Question 9

What is the Reynolds scale of larger river objects?

Answer 9

Over 10

Question 10

What’s the Reynolds number of a medium object, eg fish?

Answer 10

Between 10 and 0.1

Question 11

What is the Reynolds number of a small object, bacterium

Answer 11

Less than 0.1

Question 12

How does water get from the ocean to the river?

Answer 12

Evaporation condensation precipitation

Question 13

What is river temperature dependent on?

Answer 13

Origin, tribe, air temp, season, time of day, water depth and discharge, substrate and amount of turbulence