1: Survival

Question 1

Describe the epipelagic zone of the ocean

Answer 1

Sunlight/photic zone
- up to 200m

Question 2

Describe the mesopelagic zone of the ocean

Answer 2

Twilight/aphotic zone
200-1000m

Question 3

Describe the Bathypelagic zone of the ocean

Answer 3

Midnight/aphotic zone
1000-4000m

Question 4

Describe the Abyssopelagic zone of the ocean

Answer 4

The Abyssal Zone
4000 - 6000m
Ocean basin (abyssal plain) at 6000m

Question 5

Describe the Hadalpelagic zone of the ocean

Answer 5

The Trenches
6000 - 11,000

Question 6

What do the organisms of the abyssal plain generally rely on for food?

Answer 6

Marine snow
= waste products of organisms at the top that floats down

Question 7

How do organisms on the abyssal plain usually feed?

Are there any exceptions?

Answer 7

Filter feeders, but some evolve to be predators e.g Harp sponge

Question 8

Define Pelagic

Answer 8

Suspended / swimming in water
Over continental shelf/ slope and abyssal plain

Question 9

Define Nekton

Answer 9

organism can actively swim around

Question 10

Define Plankton

Answer 10

organism passively floats around

Question 11

Define Benthic

Answer 11

bottom (organisms live in/on muddy deposits)

Question 12

Define errant

Answer 12

mobile/active

Question 13

Define Sessile

Answer 13

unable to move - attached

Question 14

Define sedentary

Answer 14

unattached, immobile

Question 15

Give some advantages to living in the ocean

Answer 15

• High productivity
• Constant temp (high SHC)
• Constant O2
• Buoyancy allows larger body size
• Allows external fertilisation, larval stages

Question 16

Describe the esturine environment.

Answer 16

• Fresh and marine water
• Salt marshes, esturies, mangroves
• Productive, but not diverse

Question 17

Describe the freshwater environment.

Answer 17

• Less constant temp and O2 than marine
• Osmotic regulation required
• Turbidity, velocity and volume (freezing and drying) can change

Question 18

Compare fertilisation and development in marine, freshwater, and terrestrial ecosystems

Answer 18

Marine:
- External fertilisation
- Larval stage
- Very stable

Freshwater:
- Eggs retained by parent or attached to bottom
- Direct development

Terrestrial:
- Internal fertilisation
- Eggs protected (either internally or by aminotic sac and shell)