Topic 2 - Oceans

Question 1

4 reasons the ocean is essential

Answer 1

1. Where life began- first organisms were found here.
   - evolved over billions of years to what we know today
   - 500 million years ago plants and animals started to leave oceans and adapt to land life
   - the human body still needs the ions in ocean water
2. Source of our fresh water - water cycle
3. Helps regulate the atmostphere - supplies atmosphere with oxygen control the level of carbon dioxide.
4. Affects climate - heats up slower than land, costal places colder in summer and warmer in winter compared to inland. - helps transfer of heat to colder regions, affects climate of colder countries. - two kinds of curry that carry heat - the global conveyor

Question 2

The water cycle

Answer 2

1. Suns heat evaporates ocean water
2. Warm moist air rises and cools -> water vapour condenses into clouds of water droplets
3. Water droplets grow larger, fall as rain sleet hail snow
4. Rainwater flows over and through ground and ends up in rivers
5. Water flows back into ocean and cycle complete

Question 3

How does the ocean supply the atmosphere with o2 and help control the level of co2

Answer 3

1. Half the co2 humans produce is absorbed by the ocean
2. Phytoplankton use co2 and water to produce glucose (photosynthesis). Then use the glucose and other nutrients to grow materials.
3. At least half the o2 in the atmostphere came from oceans
4. Phytoplankton is the start of the food chain
5. Waste and dead things fall to the sea floor, burried, sometimes turn to ga. co2 is locked up in fossil fuels
6. Worms and bacteria feed on this waste, releasing co2 and nutrients, carried by ocean currents, phytoplankton recycle them

Question 4

How do we use the oceans

Answer 4

• transport and trade -> huge shipping containers import and export goods
• source of food -> fishing
• tourism industry -> cruises, recreation and water sports
• source of energy -> offshore wind farms, tidal energy
• fossil fuels
• salt extraction

Question 5

What are Coral reefs

Answer 5

• coral reefs are living organisms called polyps.
• they secrete calcium carbonate (limestone) to protect them as an outer skeleton
• coral is called rainforest because they provide a habitat for thousands of different species

Question 6

Name the 5 oceans

Answer 6

Arctic Ocean
Atlantic Ocean
Indian Ocean
Pacific Ocean
Southern ocean

Question 7

Where are the coral reefs

Answer 7

Between the tropics of cancer and Capricorn.

Large group found in the Pacific Ocean and the majority are near land.

Question 8

Conditions required for a coral reef to grow

Answer 8

Sea water
Warm water at 27c and over
Shallow water for sunlight to photosynthesise
Clear water for sunlight to photosynthesise
Light current

Question 9

5 impacts facing coral oceans

Answer 9

• flippers and people touching reefs damage it
• anchors will damage the reef
• pollution from ship engines
• flash photography scares fish
• taking parts of the reef

Question 10

Value of coral reefs

Answer 10

• aquarium trade -> supply tropical fish, sea horses and plants
• shoreline reefs -> gives protection from storms and tsunamis. Wave erosion can grow with rising sea levels.
• provides habitats
• provides jobs
• exploitation for fishing -> 4000 species of fish provide food, 25% of worlds commercial fish catch comes from here
• medicine source
• more jewellery
• source of lime for cement and building
• education and research -> learn more about marine life
• tourism -> magnet for world tourism

Question 11

5 threats to oceans

Answer 11

1. Plastic oceans
2. Coral reefs
3. Fish markets
4. Blast fishing
5. Climate change

Question 12

How are plastic oceans a threat to ocean

Answer 12

• millions of tonnes of plastic are in oceans
• tiny animals try to feed on the plastic which have toxins called DVT and PCB which impacts the food chain.
• less than 10% recycled
• each year we produce 300 million tonnes of new plastic

Question 13

Solutions to plastic being a threat to the ocean

Answer 13

Turn old plastic into fuel
Make people aware by making films
Use nets to catch plastic

Question 14

How are coral reefs a threat to the ocean

Answer 14

• Young fished are taken instead of old ones therefore they didn’t have time to reproduce
• growing trade for fish from reefs-> delicacy 30000 tonnes of reef fish imported to Hong Kong per year
• fishermen have to fish further away as lack of fish

Question 15

How do fish markets be a threat to the ocean

Answer 15

• 50% of food in Japan is from the sea
• blue fin tuna is in high demand and very expensive (avg: £1200 per fish
• people argue for a total ban on fishing blue fin

Question 16

How is blast fishing a threat to the ocean

Answer 16

• waters in phillipings are home to many coral reefs

- poison and dynamite are used to stun fish and make them easier to catch