Te Kūwaha and Māori

Tuna is a generic Māori word for freshwater eels. The word will be used interchangeably in this resource.

In comparison to the vast span of geological time, the estuaries that we see today are very recent coastal features.

There are several ways to tell the three New Zealand eel species apart.

To prepare for changes in climate, our freshwater and oceans decision-makers need information on species vulnerability to climate change.

Freshwater eels have an unusual life cycle which sees them travelling between the ocean, estuaries and freshwaters.

What does science tell us about New Zealand freshwater mussels?

Tuna are found in all sorts of habitats (places), including coastal estuaries, lakes, wetlands, rivers, mountain streams and even alpine tarns.

Longfin eels are the largest and longest-lived fish in New Zealand's freshwaters, and where they are present they are the top predator.

What does science tell us about New Zealand flounder?

The sex of tuna is not determined genetically, as in some other organisms.

Currently, the most reliable method to estimate the age of tuna is by examination of their otoliths or "ear bones"

Once eels become migrants (also known as tuna heke or tuna whakaheke) they stop feeding, and progressively develop the external features that clearly distinguish them from 'feeders'.