Lecture 1

Question 1

pros of living in the water?

Answer 1

it provides a medium that is x800 more dense than air & more viscous this means there is less need for structural support

Question 2

cons of living in water?

Answer 2

in regions with strong currents(intertidal region) major stress a placed on organisms especially given the higher density of water when compared to air
diffusion is much slower in water than air

Question 3

When do spring tides occur?

Answer 3

Spring tides occur when the sun and moon are lined up, so get
maximum gravitational pull → maximum tidal range

Question 4

When do neap tides occur?

Answer 4

Neap tides occur when sun, earth and moon form a right angle and gravitational effects are minimal

Question 5

what is the zone from 200-250m called?

Answer 5

surface layer (photic zone/pelagic)

Question 6

what is the zone from 200m-2km called?

Answer 6

midwater (mesopelagic) → deep sea

Question 7

what is the bottom layer of the ocean called?

Answer 7

Abyssal bottom (bathypelagic and abyssopelagic)

Question 8

What is the worldwide circulation of water called?

Answer 8

the thermohaline circulation

Question 9

how are the oceans often divided?

Answer 9

Oceans can be divided into biogeographical regions defined by temperature

Question 10

which light wavelength penetrates water the best?

Answer 10

blue

Question 11

which light wavelength penetrates water the worst?

Answer 11

red

Question 12

What are the basic nutrients?

Answer 12

N, Si, P and Fe (& Zn)

Question 13

What could cause nutrient supply to not be stable?

Answer 13

water column is stratified,

Question 14

What depletes nutrients In (semi)enclosed water bodies and stratified systems?

Answer 14

algal activity will deplete the nutrients leading to establishment of
oligotrophic conditions

Question 15

why are upper layers of ocean often depleted in nutrients?

Answer 15

Due to phytoplankton activity in the upper layers, these waters are often characterised by nutrient depletion.