economic activities have unintentional impacts on coasts

• what economic activity is happening and why?

  sand mining

  • Auckland Construction Projects company takes 76,000 m3 / year of sand for 20 years near shore at Pakiri
  • where the water is 5 - 10 m deep
  • why = because the quantity and value of the Pakiri sand is good and is in demand because its a finite resource
• where?

  Mangawhai, Pakiri, New Zealand
• the unintentional impacts on flows of energy and material

  • threatens reverse erosion
  • sediment is being taken away = wave energy speeds up erosion and long shore drift = beach lost
  • sandspit and dune slides back into the sea
  • no estuary
  • no boat access, just open sea
• the impacts on landforms

  damaged beaches:

  • very steep dunes at Pakiri beach
  • vulnerable to weather events
  • at Mangawhai beach, the wooden path that used to lead to the beach, is now metres above the beach
  • beach narrowing from erosion
  • dune erosion is unstoppable
• the impacts on the wider landscape

  • over 26 species of endangered birds live in that area
  • birds forced to nest closer to the sea = eggs at risk during storms and high tides
  • continued sand mining could destroy wildlife habitats and destroy harbour and estuaries into the open sea.