1. Oceans on the edge Reefs @ risk
Key ideas: locations, uses, threats and management of seas & oceans
Could you describe where coral reefs are located and then explain why?
Tropics
Shallow water
23o C
Tourism
Fishing
Aquarium trade
Shoreline protection
Education & research
Other – medical, jewellery
risk
Example = Florida Keys
Problem – tourism & tourism
Marine Protection Zone created to restrict fishing
only responsible diving could take place
education of divers and tourists
hotel construction restricted
Tourism
Trampling, anchors, sewage, big-game tourist fishing
Fishing Methods
Blast, cyanide & trawling methods all damage the ecosystems
Hotel Construction
Sand and silt is dumped out at sea, covering reef ecosystem
Global Warming
Sea water warms up and causes chemical reaction causing ‘bleaching’ and eventually dead zones
Sustainable
Management

2. Food web disruption Oceans on the edge Managing the North Sea
Overfishing – big trawling nets, massive boats, sonar
Effect some species becoming extinct (Cod in North Sea or Newfoundland, Canada)
Effect species that eat Cod die out or migrate away. Species that are eaten by Cod have population explosion (jellyfish)
Effect by-catch eg turtles, dolphins caught in large nets
Pollution– sewage, litter & farming
Effect fertilizers from farms wash into sea and cause eutrophication, where algae grows and takes all the oxygen
Effect species reduce in numbers because they mistake litter for food eg turtles and plastic bags
Global Warming
Effect some species like cold water and have to migrate with the cold water eg cod & krill
Effect sea levels rise causing coral reefs to be flooded
Managing the North Sea
Problems: lots of countries (UK, Norway, Germany etc)
fishing quotas being sold
currents and fishstocks move around
Solutions: quotas
Cod no-take zones
small net size
proposed marine reserves