Week 11, Lecture 1: Characteristics of water

Question 1

Two types of water bodies

in relation to movement of the water in them

Answer 1

Lotic

Lentic

Question 2

Lotic water body

Answer 2

Running water

Question 3

Lentic water body

Answer 3

Standing water

Question 4

Where is turbulence in a lotic body of water?

Answer 4

Generally in the centre

Question 5

Where is turbulence in a lentic body of water?

Answer 5

Often around the edges, bottom and surface

Question 6

Is water more viscous than air?

Answer 6

Yes

Question 7

The density of water means that aquatic plants don’t need what?

Answer 7

Structural tissue

Question 8

Why does lack of structural tissue in aquatic plants mean they have a high growth rate?

Answer 8

No energy is invested in structural so more energy is invested in photosynthesis and reproduction which results in a higher growth rate

Question 9

Does air have a higher heat capacity than water?

Answer 9

No, water has a higher heat capacity than air

Question 10

Does temperature affect the density of water?

Answer 10

Yes

Question 11

As temperature decreases, what happens to water density?

Answer 11

It increases

Question 12

How does ice prevent freezing of the water beneath it?

Answer 12

Acts as an insulating barrier

Question 13

Homothermal

Answer 13

Temperature is homogenous throughout water body

Question 14

Shallow lakes

Answer 14

3m and under, rivers, estuaries and coastal waters

Question 15

Are shallow lakes homothermal?

Answer 15

Yes

Question 16

Deep Lakes

Answer 16

Over 3m deep and open ocean

Question 17

Stratification

Answer 17

Water body splits into two zones

Question 18

Why does stratification occur?

Answer 18

Circulating currents aren’t strong enough to mix

Question 19

Epilimnion

Answer 19

Upper surface layer of deep lake

Question 20

Are deep lakes homothermal?

Answer 20

No, they are stratified

Question 21

Hypolimnion

Answer 21

Bottom layer of lake

Question 22

Thermocline

Answer 22

Thin layer between the epilimnion and hypolimnion

Question 23

Is the thermocline in a fixed postion?

Answer 23

No

Question 24

Which layer of the lake do most organisms like to live in?

Why?

Answer 24

The thermocline,

It has a favourable temp. which draws some organisms, then others are drawn to them for food

Question 25

Why are algae positioned on the thermocline?

Answer 25

Nutrients available

Sunlight available

Question 26

Three types of stratification

Answer 26

Holomitic
Monomictic
Amictic

Question 27

Holomictic stratification

Answer 27

Never stratifies

Question 28

Monomictic stratification

Answer 28

Stratifiws once a year (usually summer)

Question 29

Amictic stratification

Answer 29

Permanently stratified

Question 30

Which two water bodies are amictic

Answer 30

Oceans and Antarctic lakes

Question 31

Rough way to estimate the transparency of the water/ depth of disappearance

Answer 31

Secchi disk