Connect with freshwater habitats

Freshwater homes

We can’t live without fresh water, and neither can the plants and animals in our environment. Water is in a constant cycle: it evaporates into the atmosphere and returns to the land as snow and rain.

Aotearoa has a range of freshwater environments. Ice and snow in the mountains give way to rivers and streams, which eventually flow into the ocean. There’s also water deep underground, and freshwater wetlands that act as filters. Our native animals live in all of these places.

Sacred awa, invaluable habitat

On the land’s surface, lakes, rivers / awa and ponds are the most common freshwater environments. Tangata whenua have strong connections to their awa as part of their genealogy because fresh water sustains the taniwha and protects wāhi tapu (sacred areas).

Many of our native freshwater fauna live in rivers and streams, and may separate themselves into slow-flowing water, pools or rapids depending on the oxygen levels, nutrients, temperatures and sedimentation. One way scientists can assess stream water quality is by looking at which faunal communities are present! Here are some of our lake and river dwellers.

Kōura / crayfish

Image: Flickr/epitree

Did you know that we have native crayfish in our fresh water? Our little kōura grow up to 80mm long and do most of their movement at night. When frightened, they flick their tail forward violently, shooting themselves back into their shelter.

pomahaka-rankle-burn-1200_Daniel Jack DOC

Galaxiids

Image: Pomahaka galaxias, Daniel Jack, Department of Conservation

These scaleless fish are named for their galaxy-like gold flecks and patterns. Some of our galaxiid species migrate to sea to breed, but others live their entire lives where they hatch. We have 25 species of galaxiids here, including the īnanga and kōkopu. Some species, such as the banded, giant and shortjaw kōkopu, are found nowhere but Aotearoa. Others, such as the clutha galaxiid, are only found in a single catchment!

Did you know juvenile galaxiids are what we call ‘whitebait’?

READ ABOUT WHITEBAIT HERE

Panoko / torrentfish

Image: Stella McQueen, Creative Commons

The English name, torrentfish, says it all. These fish live in white rapids and use their flat head and pectoral fins to anchor to the riverbed. Panoko are part of the family ‘Cheimarrichthyidae’, but are its only known species!

LEARN ABOUT FRESHWATER FISH MIGRATION

Water underground

Groundwater and cave habitats are valuable underground water stores, and may support the water table even when rivers run dry over summer. They are very dark, so they can’t support plant life. Despite this, animals survive here, relying on food that comes from outside the system.

Sygofauna

Image: Phreatogammarus fragilis, ‘fragile well shrimp’, Sciblogs, Nelson Boustead

We don’t give much thought to our underground waters, but stygofauna spend their entire lives there! The term ‘stygofauna’ collectively refers to fauna that live in groundwater systems.

In Aotearoa, these range from crustaceans and gastropod snails to flatworms and beetles. Some even live 20 metres below ground level. We have a huge diversity of species in Aotearoa: there are 130 known, but experts think there could be as many as 450 species here.

More than swamps

Wetlands are areas where the water table is at or near the land surface, making it permanently or temporarily covered in either fresh water or salt water. These habitats are important for preventing floods, catching sediment, supporting nutrient cycles and supporting native species like tuna / eels. Sadly, Aotearoa has lost more than 90 percent of its wetlands to make way for farms and houses.

Tuna / eels

At up to two metres long, the longfin tuna is one of the largest eels in the world. They live only in Aotearoa, except for a trip to somewhere near Tonga or east of New Caledonia for breeding — amazingly, the exact location is still unknown!