Te Kūwaha and Māori

What does science tell us about New Zealand freshwater mussels?

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.

Knowing the age (i.e. proportion of young vs. old) of eels in an eel population provides an understanding of how fast they grow and may give an indication of the pressures faced by tuna in a particular environment or habitat.

Every year, a proportion of eels mature and migrate to sea to spawn. 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'.

A number of individuals, organisations and hapū have contributed to the development of Ngā Waihotanga Iho.

Traditionally, tangata whenua have collected information about estuaries to monitor resources, such as kaimoana, and to make decisions about conservation measures, such as rähui. Increasingly, tangata whenua are using scientific tools to help monitor their natural resources and Ngä Waihotanga Iho provides a science perspective for talking about environmental issues and concerns related to estuaries.

Through the Te Wai Māori fund Ngā Repo o Maniapoto is a collaborative project between NIWA and the Maniapoto Māori Trust Board (MMTB) Whanake Taiao team that looks to develop an inventory of repo and puna (springs) for the Maniapoto rohe.

New Zealand’s freshwater and estuarine resources provide significant cultural, economic, social, and environmental benefits. Competition for the use of these resources is intensifying, and many rivers, lakes and estuaries are now degraded.

The tools available for restoring kōura to lakes and streams depend on what is causing kōura to decline.

Identifying the factors causing kōura numbers to decline will allow you to determine which restoration tools you need to employ.