Atmospheric analysis

Discharging into a waterway is likely to impact water quality.

NIWA has produced revised safe levels of dissolved oxygen for fish, which will help inform future environmental planning and resource consents and help to keep New Zealand rivers full of healthy fish.

Setting water quality standards is a tricky business. Suitability for use is currently judged against guidelines that suggest water suddenly becomes ‘unsafe’ when a particular variable changes beyond the guideline value. For instance, according to MfE microbiological water quality guidelines (published in 2003), water is considered unsuitable for swimming once levels of E. coli – a microbe that indicates the presence of faecal bacteria – exceed 550 E. coli per 100 millilitres. But is it suitable at 500 per 100 ml?

Mangaotama catchment, Whatawhata, Waikato – win:win for farming and the environment The Mangaotama project is one of the few studies where the effects of land use have been experimentally manipulated and tested on a catchment scale. It’s centred on a 280-hectare model hill farm at the Whatawhata Research Centre near Hamilton, in the Mangaotama catchment (a tributary of the Waipa and Waikato Rivers).

Three Cray supercomputers—Māui, Mahuika and Kupe—make up the High Performance Computing Facility.

Streams play a key role in the ecosystems of New Zealand’s unique landscape. They feed and link together freshwater sources, maintain good water quality and support habitats that sustain our biodiversity.

Changes to the local environment and over harvesting have damaged shellfish populations in many estuaries. These projects examine the most effective way to restore these habitats and allow healthy populations of shellfish to return.

Missing data 
Breaks in the lines on the temperature graphs occur where there are missing data. For the purpose of this illustration, annual averages are calculated only where there is a complete year of monthly values available on the NIWA Climate Database. In the case of Albert Park, some data are missing due to persistent vandalism of equipment there.