Unit 1 Revision Topic 7: Oceans on the Edge. Main points you need to know Location of coral reefs How humans use and threaten oceans How climate change.

Unit 1 Revision

Topic 7: Oceans on the Edge

Main points you need to know

• 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

Coral reefs - Shallow water of 25m or less- Tropical water temperature of 24-26°c- Areas of saline (salty) water

http://www.bbc.co.uk/learningzone/clips/diversity-of-life-in-a-coral-reef/8977.html

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

Exploitation for fishing4000 species of fish provide food

25% of world’s commercial fish catch comes from coral reefs

Shoreline protectionProvide protection

from storms, tsunami and wave erosion.

Can grow with rising sea levels, protect

against climate change

Aquarium tradeSupply tropical fish, sea

horses and plants for our fish tanks!

TourismMagnet for world’s tourists

Countries in the Caribbean get over half their income from reef tourism

Education and researchLearn about marine life

Sources of medicine e.g. algae and sponges have “been used for the pharmaceutical

industry. Coral have also been used for bone grafts!

To make decorative objects such as jewellery

A source of lime for cement and building

Threats to marine ecosystems

• http://www.bbc.co.uk/learningzone/clips/the-impact-of-fishing-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

• Draw an example of an ocean food chain

• How do we affect food chains?

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 examplesUSA: 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 SchemeLevel Mark Descriptor

Level 1 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-fish-

stocks-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 no-take 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.

Key word Facebook• Write down the definition of your key word

• In your book draw a quick table:

• Walk round the room putting in ‘friend requests’ with each other

• If your key words have something in common, you can ‘accept’ and write each others key words in accept column. If not, reject.

• You need to be able to explain connections!

Accept Reject