Freshwater quality

Has a receding lower jaw and black spots behind the head.

A range of physical and chemical variables are measured in the NRWQN.

Smelt have a distinctly forked tail and a strong cucumber smell.

One of the most common species of freshwater fish in Aotearoa is the common bully or toitoi.

How do nutrients from wastewater treatment enter waterways?

How healthy is your stream? SHMAK - the New Zealand Stream Health Monitoring and Assessment Kit - has been designed to help you find out.

Tuna or freshwater eels are a very significant, widely-valued, heavily-exploited, culturally iconic mahinga kai resource.

Dissolved oxygen (DO) is a relative measure of the amount of oxygen (O2) dissolved in water.

A high proportion of New Zealand’s native freshwater fish fauna need to migrate to and from the sea.

NIWA provides national capabilities in Water Quality Monitoring