People have cleared most of our coastal lowland vegetation for farming and coastal subdivision. There is little lowland coastal forest left in the Waikato Region. Our remaining coastal forests provide important habitat for native animals. Find out about two distinctive coastal lowland areas - the Thames coast stream deltas and the Miranda shellbank.
On this page:
Thames coast stream deltas
A coastal delta forms when a stream or river meets the sea (the river mouth) and drops the sediment it is carrying. Over the last 6,000 to 7,000 years, the western Coromandel Peninsula streams have been dropping sediment and forming stream deltas on the Thames Coast.
People have changed many of the deltas through:
- subdivision
- infrastructure development (for example road building)
- coastal structures (including flood protection).
Miranda shellbank
The Miranda shellbank is an extensive shellbank (chenier plain) along the south-western margin of the Firth of Thames. It is the only chenier plain in New Zealand. Chenier plains form from old beach ridges that are left inland as the shoreline moves towards the sea. They are unique and globally rare landforms.
The Miranda shellbank is up to two kilometres wide. Waves built up the shell and gravel ridges. Many of the original ridges remain, although people have changed the area through:
- drainage
- agriculture
- sand and gravel extraction.
Miranda is also internationally famous for its wading birds. Find out more about the Firth of Thames birds.
The pdf below has the minutes from the workshop with the coastal community of the upper Firth of Thames, Miranda Shorebird Centre, held on the 6 November 2005.
Workshop minutes
(136 kb, 19 seconds to download, 56k modem)
Coastal plants
Coastal forests were once common on lowland, cliffed and rocky coasts. In the Waikato Region, people have made many changes in the coastal bioclimatic zone (roughly the area within one kilometre of the coast and less than 300 metres above sea level).
- In 1840, over 70 percent of the coastal bioclimatic zone was covered in original forest.
- Today, less than five percent remains, most of this on islands off the Coromandel Peninsula.
- Excluding these islands, original forest now makes up only half a percent of the coastal bioclimatic zone.
Areas of regenerating forest and scrub make up about 20 percent of the coastal bioclimatic zone. The regenerating forests are mostly in hilly areas and are threatened by:
- land clearance
- stock access
- pests.
These regenerating areas have a great potential for protection and restoration.
The pohutukawa, or New Zealand Christmas tree, with its brilliant crimson flowers, is a national icon. Coastal forest clearance and possum damage have devastated our pohutukawa forests. Find out more about protecting and planting pohutukawa on the Project Crimson website.
Coastal animals
Before human settlement many of our coastal forests would have teemed with seabirds (petrels, storm petrels, and shearwaters). But introduced pests such as cats and rats have destroyed most mainland seabird colonies.
Our coastal forests are still very important for other native animals:
- Coastal flax and pohutukawa provide nectar for birds (such as tui and bellbirds) and lizards (skinks and geckos).
- Large trees provide roosts and nesting sites for shags.
- Streamside plants near the coast provide spawning areas for native fish.