Freshwater Quality

Latest news

Can native freshwater algae help restore the mauri of local waterways? Lawrence Gullery investigates.
What does science tell us about New Zealand cockles?
For the first time, satellites have been used to track coastal water health around Aotearoa New Zealand.
NIWA has updated and restarted a course using a riparian planning tool developed by one of its former chief scientists more than 20 years ago.

Latest videos

SHMAK Habitat - Rubbish

The SHMAK method for rubbish involves collecting and identifying all the rubbish (litter) in the stream and on the stream banks. It was designed to complement rubbish assessments on our beaches so the data is comparable.

SHMAK Habitat – Visual Habitat Assessment

The SHMAK visual habitat assessment needs no equipment, only your eyes. It gives your stream a score that you can use to assess changes over time or compare streams.

SHMAK Habitat – Streambed Composition

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

SHMAK Stream Life – How to Sort and Identify your Benthic Macroinvertebrate Sample

An ice-cream tray provides an excellent container to isolate and separate your benthic macroinvertebrates. The SHMAK Benthic Macroinvertebrate Field Guide can help you with your identifications. Posting a photo to the Freshwater Invertebrates NZ project in iNaturalist can help you identify any invertebrates you don’t recognise - https://inaturalist.nz/projects/fresh... When you enter your data into the NZ Water Citizens website - https://nzwatercitizens.co.nz/ - you can use the online calculator to calculate a health score.

Retrospective river flows, July to September 2011

What we predicted for July 2011 to September 2011

River flows are likely to be normal in the North Island and north of the South Island, and normal or below normal in the rest of the South Island. 

What actually happened during July 2011 to September 2011

River flows were normal to below normal for most of the country, with some above normal river flows in the eastern North Island, eastern Southland and coastal Otago. 

 

Cover habitat for fish can be riparian (i.e. over the stream) or instream (e.g. wood debris or boulders).

Changes to water flow regimes can affect fish in several ways.

Fish species have varying habitat requirements. If a habitat requirement is not present, the species that rely on it will not be abundant in your stream.

A problem with recruitment is usually indicated by the absence, or very low density, of fish where they would normally be present.
Fish species thrive in a variety of different habitats.

The environmental effects of developing land and water for human use have decimated New Zealand's native fish fauna, but we now have the knowledge to reverse this trend and restore native fish in streams. 

Exotic aquatic plants, introduced to New Zealand for the aquarium and ornamental pond trade, are silently invading our waterways, but new research by NIWA scientists is helping to lower this risk by finding native alternatives for the trade.

Examples of publications produced from the National Water Quality Network are listed below.

[This list is currently under construction - please check back later]

If the low abundance of fish in your stream is not related to a reduction in habitat, waterquality, flow or the presence of downstream barriers, it might be due to the inability of juvenile fish to enter the stream.

The known water quality preferences and tolerances (temperature, pH, oxygen, ammonia and turbidity) for common native fish are shown in the table at the bottom of the page.

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All staff working on this subject

Principal Technician - Marine Ecology
Principal Scientist - Ecosystem Modelling
Principal Scientist - Aquatic Pollution
Principal Scientist - Catchment Processes
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Riparian and Wetland Scientist
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Land and Water Scientist
Surface Water - Groundwater Modeller
Principal Scientist - Aquatic Pollution
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Water Quality Scientist
Hydrology Scientist
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Catchment Modeller
Regional Manager - Auckland
Maori Organisational Development Manager
Algal Ecologist
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Principal Technician - Environmental Chemistry and Toxicology
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