Oceans

Question 1

Describe different ways in which we use the oceans.

Answer 1

Tourism and recreation
Shipping
Energy and natural resources
Defence
Settlement
Household products

Question 2

Describe the four different types of erosion.

Answer 2

Abrasion
Attrition
Corrosion
Hydraulic action

Question 3

Describe the structure of a coral polyp.

Answer 3

Question 4

Describe the food web of a coral reef and explain how it works.

Answer 4

In a coral reef ecosystem, the primary producers are plankton and algae.

Primary consumers include sea cucumbers and parrot fish.

Secondary consumers include sharks, dolphins, eels, sea horses, jellyfish, and starfish.

Decomposers are mainly bacteria.

Question 5

Describe the features of the Arctic Ocean cold desert and why there is potential for conflict.

Question 6

Explain three threats to coral reefs.

Answer 6

The top threats to coral reefs:
global climate change
unsustainable fishing
land-based pollution

Other threats include:
tropical storms,
disease outbreaks,
vessel damage,
marine debris
invasive species

Question 7

Understand some of the arguments for and against a ban on commercial fishing in Palau.

Question 8

What is erosion?

Answer 8

Erosion is the wearing away of the land by the sea.

Question 9

Describe the food web of a coral reef and explain how it works.

Question 10

What are ocean currents?

Answer 10

Ocean currents are the continuous
predictable
directional movement of seawater driven by gravity
wind (Coriolis Effect), and water density.

Question 11

Should fishing be banned in Palau?

Question 12

Name the main causes for overfishing.

Answer 12

Increase in fishing for domestic sale
Increase in fishing due to foreign trawlers
Fishery management with a protected area
Population increase
Specific species overfished
Use of dynamite fishing

Question 13

Name the world’s oceans.

Answer 13

Pacific
Atlantic
Indian
Arctic
Southern (Antarctic).

Question 14

What is the deepest part of the ocean?

Answer 14

The Mariana Trench.

10911km below the surface of the water.

Question 15

What is the structure of the ocean like - starting with the most shallow part?

Answer 15

The continental shelf
Continental slope
Continental rise
Deep seabed/Oceanic Crust

Question 16

Which organisations look after our oceans?

Answer 16

Marine Management Organisation

Royal Navy

UN (United Nations)

Plymouth Marine Laboratory

WWF (World Wildlife Fund)

Question 17

Name the zones in the ocean, starting with the most shallow.

Answer 17

0-200m Sunlight Zone

200 - 1000m Twilight Zone

1000-4000m Midnight Zone

4000 - 6000m The Abyss

6000-11,000m The Trenches

Question 18

What are Territorial Seas (waters)?

Answer 18

Extends 22km from the shore and legally regarded as an extension of the land of the country so the laws of that country apply here too.

Question 19

What is beyond Territorial Seas (waters)?

Answer 19

‘High Seas’ or ‘International Waters’

You are then out of the jurisdiction of the legal authorities of that country.

Question 20

Define Exclusive Economic Zone.

Answer 20

This is an area of sea that extends 370km from the shore of a country and gives that country the right to explore and exploit the natural resources of the sea and seabed.

The laws of the country do not apply in the EEZ beyond the 22km of the territorial sea.

Question 21

How long does it take from a headland to erode and become a stump?

Answer 21

Thousands or even millions of years.

Question 22

Describe how you get from a headland to a stump.

Answer 22

1) A large crack is formed, opened up by hydraulic action.
2) The crack grows into a cave by hydraulic action and abrasion

3) The cave becomes larger

4) The cave breaks through the headland forming a natural arch

5) The arch is eroded and collapses

6) This leaves a tall rock stack

7) The stack is eroded forming a stump

Question 23

Ocean water moves in two directions: horizontally and vertically.

Horizontal movements are referred to as …., while vertical changes are called ……

Answer 23

Currents

upwellings or downwellings

Question 24

What is an eco-system?

Answer 24

An ecosystem is a group of living organisms interacting with the non-living parts of an environment.

Ecosystems can vary in size, eg a single hedgerow or a whole rainforest.

Question 25

What is a coral polyp?

Answer 25

It is an animal but living inside its stomach are algae which convert energy from the sun into food for the coral. The polyp also catches zooplankton (tiny microscopic animals) with its tentacles to supplement the food from the algae. The polyps cluster together and some form a calcium carbonate exoskeleton called corallite which builds up the rocky reef.

Question 26

Is Coral a plant or an animal?

Answer 26

It is an animal but living inside its stomach are algae which convert energy from the sun into food for the coral (like a plant). The polyp also catches zooplankton (tiny microscopic animals) with its tentacles to supplement the food from the algae.

Question 27

The polyp and zooxanthellae have a symbiotic relationship. What does this mean?

Answer 27

They rely on each other for food and shelter.

Question 28

The ....Ocean is the smallest of the world’s five oceans.

Answer 28

Arctic

Question 29

What countries have a claim to Arctic territory?

Answer 29

Russia Canada USA (Alaska is close) Denmark (Greenland is close) Norway

Question 30

Why are coral reefs under threat from humans?

Answer 30

Turbidity Crown of thorns starfish Fertiliser run-off Storms Overfishing Tourism Ocean acidification Warming oceans

Question 31

What is turbidity?

Answer 31

Turbidity is a measure of the level of particles such as sediment, plankton, or organic by-products, in a body of water. As the turbidity of water increases, it becomes denser and less clear due to a higher concentration of these light-blocking particles.

Question 32

What is a crown-of-thorns starfish?

Answer 32

The crown-of-thorns starfish is a large starfish that preys upon hard, or stony, coral polyps. It receives its name from venomous thorn-like spines that cover its upper surface, resembling the biblical crown of thorns. It is one of the largest starfish in the world.

Question 33

What is fertiliser run off?

Answer 33

Too much fertilizer can actually kill the plant and excess fertilizer can runoff into streams and lakes causing toxic algal blooms that are harmful to aquatic life.

Question 34

Why is ocean acidification a problem for coral reefs?

Answer 34

Ocean acidification slows the rate at which coral reefs generate calcium carbonate, thus slowing the growth of coral skeletons.

Question 35

How does ocean warming affect coral reefs?

Answer 35

Rising water temperatures can stress coral polyps, causing them to lose algae (or zooxanthellae) that live in the polpys' tissues. This results in “coral bleaching,” so called because the algae give coral their colour and when the algae “jump ship,” the coral turns completely white.

Question 36

Why is plastic debris in the oceans an issue?

Answer 36

It causes injuries and deaths of numerous marine animals and birds. They become entangled in it or they mistake it for prey and eat it.