Braided Rivers

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Braided rivers are found in only a few places around the world. They are made up of wide gravel beds, many channels and changeable water flow. Many special plants and animals live in and around braided rivers.

Why braided?

Rocks that fall down mountainsides end up in rivers. The rocks are carried downstream by floods. When the slope of the river flattens out on the plains, the rocks are set down. In big floods the rocks and sediments are carried out across the plains toward the coastline.

Braided rivers are made when these rocks and sediment build up on the riverbed. In time the build-up becomes so high that the water begins to flow down a new channel. These changes happen all the time and are a key part of braided river systems. This is also part of the reason these rivers are such productive ecosystems.

Flora and fauna

Birds

About 26 bird species feed and breed on our braided rivers. These include:

  • Ngutu pare/wrybills
  • Tōrea tuawhenua/South Island pied oystercatchers
  • Kakī/black stilts
  • Tuturiwhatu/banded dotterels.

A few seabird species breed along braided rivers too:

  • Tarapiroe/black-fronted tern
  • Tara-nui/Caspian tern
  • Tara/white-fronted tern
  • Kawau/black shag
  • Tarāpunga/black-billed gull.

Invertebrates and lizards

Braided rivers and wetlands are home to many aquatic invertebrates such as:

  • dobsonflies
  • mayflies
  • stoneflies
  • caddisflies
  • waterboatmen
  • red coat damselflies
  • Sandflies.

These invertebrates are a food source for fish and birds.

Lizards are also found around braided rivers, such as:

  • McCann’s skink/mokomoko
  • long-toed skink
  • scree skink
  • spotted skink
  • jewelled gecko.

Fish

Some fish live in braided rivers and their connected wetlands. Some of these fish are:

  • lowland longjaw galaxias and upland longjaw galaxias
  • longfin eel/tuna
  • kōaro
  • Canterbury galaxias
  • alpine galaxias
  • upland bully
  • common bully.

Braided rivers are also home to popular sport fish such as trout and salmon.

Braided river plants

In braided rivers there is a range of low growing plants. These plants are able to grow amongst shifting gravels, hot and cold temperatures and few nutrients. Some special plants are the forget-me-not and the rare tiny woodrush. Others include mat daisy and the native daphne/pinatoro.

Important for people

People use braided rivers for recreation such as jet boating, fishing, walking, bird spotting and swimming. They are also an important tourist attraction.

Braided river-mouths are culturally significant for Ngāi Tahu. The Waitaki River is the ancestral river of Ngāi Tahu. The Waitaki River was a key provider of mahinga kai resources and a way of travelling by reed raft (mōkihi).

Where are braided rivers?

This map below shows the braided reaches of the 163 braided rivers in New Zealand. The larger rivers from each region have been labelled.

Threats

Braided rivers are under threat from:

  • weeds that stabilise the naturally changing water channels
  • predators that prey on native birds, lizards and insects
  • introduced fish that compete with native fish species
  • the use of water from rivers for electricity generation and irrigation
  • people who may crush bird nests and chicks with vehicles or scare birds from their nests. This leaves eggs and chicks open to predation and weather extremes.

How can you help?

  • Riverbed birds nest between July and February. They need special consideration during this time.
  • Keep pets away from riverbeds and keep dogs on a leash at all times.
  • Keep clear of nesting colonies and watch out for eggs and chicks. They are hard to see and very fragile.
  • If you disturb birds accidentally, move on quickly so that the birds can return to their nests.
  • Try not to drive vehicles on riverbeds. Park on the bank and walk to where you want to go.
  • The speed limit for boats is 5 knots within 200 metres of the bank. Jet boats disturb birds and wash away nests.
  • Above all, respect braided rivers and the plants and animals that live in and around them.

 

Audio Māori keywords: 


Compare: Make a comparison between a braided river and another type of river that you may have near your place.

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Braided rivers are made up of wide gravel beds and many channels. Image: LEARNZ.

Rocks that fall down the mountainsides are carried downstream by floods. What does this movement do to the shape of the rocks? Image: LEARNZ.

Braided rivers are very changeable environments. How does this changing nature help them? Image: DOC.

Many birds, such and this wrybill/ngutu pare, rely on braided rivers for their survival. What other birds might you find there? Image: Brad Edwards.

Invertebrates living in braided rivers are a source of food for birds and fish. Can you identify the invertebrates in this picture? Image: LEARNZ.

Lizards make use of braided river habitats to live and breed. Why do you think it is a good place for them? Image: DOC.

As well as native fish species, braided rivers are home to popular sport fish such as salmon. What do the salmon use the rivers for? Image: LEARNZ.

In braided rivers there are a range of low growing plants, like this mat daisy, adapted to growing amongst shifting gravels. What adaptations might these plants need? Image: LEARNZ.

Braided rivers are highly valuable for a wide range of recreational activities. It is important that we all look after them. In what ways do people value them? Image: LEARNZ.