Oceans Flashcards
Describe different ways in which we use the oceans.
Tourism and recreation
Shipping
Energy and natural resources
Defence
Settlement
Household products
Describe the four different types of erosion.
Abrasion
Attrition
Corrosion
Hydraulic action
Describe the structure of a coral polyp.
Describe the food web of a coral reef and explain how it works.
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.
Describe the features of the Arctic Ocean cold desert and why there is potential for conflict.
Explain three threats to coral reefs.
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
Understand some of the arguments for and against a ban on commercial fishing in Palau.
What is erosion?
Erosion is the wearing away of the land by the sea.
Describe the food web of a coral reef and explain how it works.
What are ocean currents?
Ocean currents are the continuous
predictable
directional movement of seawater driven by gravity
wind (Coriolis Effect), and water density.
Should fishing be banned in Palau?
Name the main causes for overfishing.
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
Name the world’s oceans.
Pacific
Atlantic
Indian
Arctic
Southern (Antarctic).
What is the deepest part of the ocean?
The Mariana Trench.
10911km below the surface of the water.
What is the structure of the ocean like - starting with the most shallow part?
The continental shelf
Continental slope
Continental rise
Deep seabed/Oceanic Crust
Which organisations look after our oceans?
Marine Management Organisation
Royal Navy
UN (United Nations)
Plymouth Marine Laboratory
WWF (World Wildlife Fund)
Name the zones in the ocean, starting with the most shallow.
0-200m Sunlight Zone
200 - 1000m Twilight Zone
1000-4000m Midnight Zone
4000 - 6000m The Abyss
6000-11,000m The Trenches
What are Territorial Seas (waters)?
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.
What is beyond Territorial Seas (waters)?
‘High Seas’ or ‘International Waters’
You are then out of the jurisdiction of the legal authorities of that country.
Define Exclusive Economic Zone.
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.
How long does it take from a headland to erode and become a stump?
Thousands or even millions of years.
Describe how you get from a headland to a stump.
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
Ocean water moves in two directions: horizontally and vertically.
Horizontal movements are referred to as …., while vertical changes are called ……
Currents
upwellings or downwellings
What is an eco-system?
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.
What is a coral polyp?
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.
Is Coral a plant or an animal?
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.
The polyp and zooxanthellae have a symbiotic relationship. What does this mean?
They rely on each other for food and shelter.
The ….Ocean is the smallest of the world’s five oceans.
Arctic
What countries have a claim to Arctic territory?
Russia
Canada
USA (Alaska is close)
Denmark (Greenland is close)
Norway
Why are coral reefs under threat from humans?
Turbidity
Crown of thorns starfish
Fertiliser run-off
Storms
Overfishing
Tourism
Ocean acidification
Warming oceans
What is turbidity?
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.
What is a crown-of-thorns starfish?
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.
What is fertiliser run off?
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.
Why is ocean acidification a problem for coral reefs?
Ocean acidification slows the rate at which coral reefs generate calcium carbonate, thus slowing the growth of coral skeletons.
How does ocean warming affect coral reefs?
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.
Why is plastic debris in the oceans an issue?
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.
