Transcript File - All Hallows Geography

Unit 1 Revision
Topic 7: Oceans on the Edge
Main points you need to know
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Location of coral reefs
How humans use and threaten oceans
How climate change can threaten oceans
What food webs are
How oceans can be sustainably managed
Case Study: Firth of Clyde, Scotland
Case Study: Global Management (e.g.
CITES)
Location of coral reefs
http://www.bbc.co.uk/learningzone/clips/div
ersity-of-life-in-a-coral-reef/8977.html
Coral reefs
- Shallow water of 25m or less
- Tropical water temperature of
21-29°c
- Areas of saline (salty) water
What is the value of coral reefs?
http://www.youtube.com/watch?v=QJ58QQrDs4c&feature=player_embedded
..\Teachers TV Downloads\Biologists_create_new_Red_Sea_reefs__24_Aug_07_1.wmv
Tourism
Magnet for world’s tourists
Countries in the Caribbean get over half
their income from reef tourism
Education and research
Learn about marine life
Exploitation for fishing
4000 species of fish provide food
25% of world’s commercial fish catch
comes from coral reefs
Shoreline protection
Provide protection
from storms, tsunami
and wave erosion.
Can grow with rising
sea levels, protect
against climate change
A source of lime for cement
and building
To make decorative objects such
as jewellery
Sources of medicine e.g. algae and sponges
have “been used for the pharmaceutical
industry. Coral have also been used for bone
grafts!
Aquarium trade
Supply tropical fish, sea
horses and plants for our
fish tanks!
Threats to marine ecosystems
• http://www.bbc.co.uk/learningzone/clips/the-impact-offishing-in-the-philippines/4692.html
• Population growth
• Land development
• Pollution from cars and industry
• Coral mining for sand and lime
• Methods of fishing
• Overfishing
• Tourism
• Global warming
Food chains
• Draw an example of
an ocean food chain
• How do we affect
food chains?
How do we disrupt nutrient cycles?
Eutrophication
Using named examples, explain how humans can
have both positive and negative impacts on
marine ecosystems. (6 marks)
Natural threats to ecosystems
• Hurricanes
• Parrot Fish
• Crown of thorn star fish
Impacts of climate change
• http://www.youtube.com/watch?v=mkCWI7CwR_0
Impacts of climate change
• Increases in temperature  coral ecosystems
become vulnerable to bleaching
• Extreme weather events such as storms and
flooding 
• Increases in temperatures  glaciers melt 
increase in freshwater into the oceans
• Higher sea levels  mangrove swamps/ salt
marshes could be submerged
• Coral reef islands such as Maldives would be
completely submerged
• Thermal expansion
Named examples
USA: Sea level causes
increased coastal erosion
and flooding. Risk of storm
surges in Florida. Threats to
coastal wetlands
Asia: Increasing intensity of
tropical cyclones could threaten
mangroves and coral reefs
Europe: Low lying countries
such as Denmark and the
Netherlands will be
submerged
Bangladesh: Storm surges will
increase and grow in strength.
Sea level rise of 45cm would
displace 5.5m people
• Exam Question: Explain how climate
change is adding stress to marine
ecosystems. (6 marks)
Answers
Mark Scheme
Level
Level 1
Mark
Descriptor
1-2 Answer identifies at least one cause of additional
stress which has resulted from global warming.
Limited subject vocabulary used.
Level 2
3-4 An attempt has been made to explain at least
one threat. Some elaborated / extended
statements. A range of subject specific terms
have been used.
Level 3
5-6 Detailed / well developed answer. At least one
threat has been clearly explained. Answer
includes clear linkage. Effective use of subject
specific terms.
Named case study: marine
resources under pressure
• The Firth of Clyde,
Scotland
• 60km stretch of water
along west coast
Threats facing the Firth of Clyde
• http://www.bbc.co.uk/learningzone/clips/why-have-fishstocks-decreased-in-the-north-sea-pt-1-2/4687.html
• Fishing - Overfishing of species like cod have caused
the numbers to crash
• Tourism – Tourism has developed. Now the 2nd largest
yachting centre which disturbs wildlife
• Sewage disposal - In the past on-land sewage
treatments were limited so waste from toilets flowed
straight into the sea. Now less of a problem
• Military Testing - Perfect testing ground for the Royal
Navy’s nuclear submarines. A serious accident would
have terrible effects on the ecosystem
Management
• Local divers formed COAST which campaigned for a notake zone to be established in Lamlash Bay.
• In 2008 the Scottish Government made part of Lamlash
Bay a no-take zone, the rest of the bay is a management
area where scallops can be fished but only in less
destructive ways
• Will soon be designated a Coastal and Marine Park
(CMP) to ensure that coastal and marine-based activities
are managed in a sustainable way to bring long term
economic benefits to people, whilst protecting the
environment
• Scottish Marine Bill – new set of laws to help manage
future conflicts in Scottish waters
Sustainable Management
• Sustainable Management is a balancing
act between ecosystem conservation and
helping local people to make a living
without overharvesting resources
• What might it involve?
Named case study – Regional
Scale
• North Sea fishing - Problem?
• Solutions?
• Ensuring mesh of the nets allows young undersized fish
to escape
• Limiting the hours and days fishing boats can operate
• Quota management – limit placed on the number of
tonnes of fish from each species that can be caught
• Setting up marine reserves which protect all species
• Further research into how fishing affects the whole
ecosystem
Named case study – Global
Solutions
• CITES (Convention of International Trade
in Endangered Species of Wild Fauna
and Flora)
• This gives global protection to all of the
great whales as many species of whales
were hunted almost to extinction during
the 20th century.
• CITES also helped protect other species
such as sturgeon fish whose eggs were
used to make caviar.
Named case study – Global
Solutions
• Law of the Sea
• This was developed to prevent certain
nations from taking an unfair share of the
ocean’s wealth.
• The treaty was established in 1994 and
40% of the ocean was placed under the
law of adjacent coastal states.