Freshwater quality

A new study has identified seven freshwater species native to Aotearoa-New Zealand that will likely be highly or very highly vulnerable to climate change.

Te Nehenehenui (previously Maniapoto Māori Trust board) and NIWA are working collaboratively to support Ngāti Maniapoto whānau to reconnect with and participate in the assessment of their freshwater according to their values.

Eutrophication occurs when nutrients in streams, rivers, lakes and estuaries cause excessive growth of aquatic plants and algae (primary producers).

Constructed wetlands are a water quality restoration tool that can reduce levels of sediment, nutrients and microbes such as E. coli.

What does science tell us about New Zealand freshwater crayfish?

The SHMAK method for rubbish involves collecting and identifying all the rubbish (litter) in the stream and on the stream banks.

The SHMAK visual habitat assessment gives your stream a score that you can use to assess changes over time or compare streams.

Two methods for describing streambed composition: the visual assessment method is quicker while the Wolman walk is more accurate.

Use an ice-cream tray to isolate and separate your invertebrates. The Benthic Macroinvertebrate Field Guide helps you with identification.

Before you look at what animals you have collected, follow these methods to clear away debris (stones, sand, leaves, twigs) from your sample in the net.

If your stream has a muddy-bottom or soft-bottom (made of silt or mud), you need to use a different method than if your stream has a stony-bottom.

Use a net & the kick-net method to collect a greater range of benthic macroinvertebrates and more accurately assess the diversity of the community.