Ō Tū Wharekai has been shaped by glaciers and provides a variety of habitats. Because the landscape is so varied it is able to support a large amount of wildlife.
There are over 30 bird species that regularly use the lakes and wetlands. Ō Tū Wharekai contains the upper Rangitata River, which includes one of the most important breeding sites for the threatened wrybill/ngutu pare.
Other birds such as the Austalian bittern/mātuku, and the Australian crested grebe/kāmana can be found at Ō Tū Wharekai.
As well as birds and fish, Ō Tū Wharekai is also home to minute animals called zooplankton, that live in the water.
Ō Tū Wharekai is also an important site for kettle holes which support rare ephemeral turf vegetation. The swamps of Ō Tū Wharekai include a threatened sedge.
Plants aren’t just restricted to above water, Ō Tū Wharekai has a huge diversity of macrophytes or aquatic plants, including freshwater algae.
There are many threatened animals and plants living in Ō Tū Wharekai.
Threatened native fish
- longfin eel/tuna
- upland longjaw galaxias (small, freshwater fish).
- Threatened bird species
- Australasian bittern/Mātuku
- black-fronted tern/Tarāpirohe
- black-billed gull/Tarāpuka
- wrybill/Ngutu pare
- banded dotterel/Turiwhatu
- Australasian crested grebe/Kāmana
- Caspian tern/Tārā nui.
Threatened lizard species
- scree skink/mokomoko
- long-toed skink.
Threatened plant species
- marsh arrowrush
- pygmy forget-me-not
- pygmy clubrush
- native lily
- water brome
- rare grasses.
These wetlands also contain some of the best examples of red tussock and pūkio wetlands in Canterbury.