oceanic islands

• Oceanic islands


  Islands formed by volcanic eruption, often isolated and with limited biodiversity
• Mauritius

  • Oceanic island in Africa just east of Madagascar
  • Formed approximately 10 million years ago by volcanic eruption
  • Home to the famous Dodo bird which is now extinct
• Ecological features of oceanic islands

  • Isolation & Biodiversity:
  • Limited biodiversity due to small number of species able to colonise
  • Majority of species are marine and seabirds as they have easier access to colonise
  • Some colonise by chance like tortoises from drifting on a piece of wood
  • Due to the difficulty to colonise there is many endemic species from the original colonists
• Endemic species of Mauritius

  • Mauritian Kestrel
  • Mauritian flying Fox
  • Dodo (extinct)
• Endemic species

  • Platypus (Australia)
  • Galapagos land iguana

  
• Ecological features of oceanic islands

  • Lack of Mammal Predators:
  • It is difficult for mammals to colonise isolated islands due to the difficult access
  • Bats may be able to but terrestrial mammals usually don't
  • Some larger islands still have mammals from when they were attached to larger continents
• Mammal species in Mauritius

  • Only 19, the Mauritian Flying Fox being one of the only predators
• Mammals in larger islands

  • Marsupials (kangaroo & wombat) of Australia
  • Lemur of Madagascar
• Mauritius is a sanctuary for a rich variety of flora and fauna
• Mauritius is renowned for its diverse biodiversity, making it a true gem in the Indian Ocean
• Much of the unique flora and fauna have evolved over a million years on the island, resulting in many endemic species
• The island hosts outstanding biodiversity including sea turtles and dolphins as well as coral reefs with masses of tropical fish
• Mauritius is also home to mangroves which are home to nesting migratory birds
• Due to thermal expansion and climate change, the sea level surrounding Mauritius has been rising by 3.8mm per year from 1988


  The risk of flooding has increased as there is less transpiration from the plants absorbing water
• As floods are more common due to the rise of sea level


  Many plants are dying due to osmotic dehydration and habitats are being washed away
• With land space for tourist attractions becoming more limited


  More habitats are being destroyed for urbanisation
• The sugarcane industry is one of the biggest industries in Mauritius with 3 million tonnes being produced


  Clearing the land for the crop fields massively reduces biodiversity and threatens species as their habitats are being lost
• The Mauritius Blue Pigeon was an endemic species to Mauritius but is now extinct due to deforestation and habitat destruction
• Conservation efforts


  • Attempts to stop or reverse damaging effects of human actions
  • Eradication of introduced species as they can outcompete native species for food, water, and space and they can introduce new disease
• Mauritius conservation efforts


  • The Mauritian Wildlife Foundation is the largest non-governmental organisation in Mauritius, it is concerned with the conservation of endangered endemic plants and animals of Mauritius
  • Mauritius protects biodiversity by creating multiple national parks and removing invasive species, such as Mikania Micrantha which is difficult to control
  • The native forests which originally covered most of the island have almost completely disappeared so the areas left have been converted to national parks or nature reserves
  • MWF has been able to reintroduce endemic bird species such as the Mauritius Cuckoo-shrike and save them from extinction