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 Reefs @ 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

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