Bacteria and parasites like campylobacter, salmonella, and cryptosporidium can contaminate our food and water, leading to serious illness. Campylobacter, salmonella, and cryptosporidium are influenced by temperature and other climate variables, and incidence rates may increase as climate change causes temperatures to rise. Monitoring the incidence rates...

River water quality water is valued for many reasons including ecological function and habitat, recreational value, its role in supporting people and industry, and its cultural significance. Nutrients such as nitrogen and phosphorus are essential for plant growth, however too much in rivers can lead to ‘nuisance’ growths of river algae and aquatic plants,...

"Small amounts of nitrogen are a natural component of healthy rivers. Nitrogen is transferred from land to water and is cycled through different forms, which can have different effects. Moderate concentrations of nitrate can cause weeds and algae to grow too fast. High concentrations of ammoniacal and nitrate nitrogen can be toxic to fish and other...

The ocean storm index estimates the number of days in a year when wind speeds exceed gale and storm force on the Beaufort Scale. In a gale, sea conditions are rough and waves can be over six metres high. In a storm, waves can be over 10 metres high. To put this into context, on land a near gale would make walking difficult, and a storm would cause some...

Influenza is a potentially life-threatening virus that spreads quickly from person to person. It is a significant public health issue in this country, with 10–20 percent of New Zealanders infected every year. While influenza outbreaks can occur all year round, rates peak in winter and spring. This is because the virus can survive longer outside the body...

"Phosphorus is an essential nutrient for plant and animal life. Total phosphorus (TP) includes all concentrations in a sample, whether dissolved, in solid form or bound to sediment in the river. Dissolved reactive phosphorus (DRP) is the portion which is dissolved and can immediately support plant and algae growth. Excess phosphorus in our rivers can...

"Freshwater plant and animal pests can have significant negative impacts on ecosystem health by reducing indigenous biodiversity through predation and competition, and destabilising aquatic habitats. Freshwater plant pests can cause economic losses through blocking water intakes for hydroelectricity generation, impeded drainage or irrigation. In addition,...

Maximum ozone concentration during 8-hour periods. Note: Ozone concentrations are given in micrograms per cubic metre of air, or µg/m3. Source: Auckland Council

Nitrogen dioxide (NO2) is a gas. It can be emitted directly into the air but is most often formed when nitric oxide (NO) emissions react with other chemicals in the air. Nationally, road motor vehicles are the main human-made source of nitrogen oxides (NOx, the collective term for NO2 and NO). NO2 may cause respiratory infections and reduced lung...

Note: PM10 concentrations are given in micrograms per cubic metre of air, or µg/m3. Source: Regional councils of Waikato, Wellington, Canterbury, Otago; Auckland Council

Urban water quality indicators include heavy metals, nutrients, and E.coli. The concentrations of these indicators are compared to the proportion of urban land cover in catchments. Heavy metals have the ability to accumulate in sediments, shellfish, and other aquatic organisms. Metals can reach toxic levels in organisms making them unsafe to consume and...

New Zealand waters have at least 113 species of chondrichthyans (sharks, rays, and other cartilaginous fish species). They are particularly vulnerable to overfishing because they are long-lived, mature slowly, and have a low reproductive rate. Chondrichthyans are important for healthy ocean ecosystems, and reporting their commercial catch and bycatch...

Ozone (O3) is a gas that is of interest in two regions of Earth’s atmosphere – at ground level and in the upper atmosphere (stratosphere). Stratospheric ozone absorbs ultraviolet (UV) rays from the sun and protects Earth from harmful levels of UV. Exposure to these UV rays has been linked to skin cancer. Monitoring variations in stratospheric ozone...

Freshwater fish are an important component of freshwater ecosystems and a valued resource for Māori and recreational fishers. The community of fish species found at a site can be affected by changes in catchment land cover and land use, in-stream habitat, fish passages (routes for moving up and down waterways), pests, and contaminants. The fish index of...

Sulphur dioxide (SO2) is a gas produced from human (eg industry and shipping) and natural (geothermal and volcanic) activities. Nationally, the main human-made source of sulphur oxides emissions is industry. SO2 is associated with respiratory problems, such as bronchitis, and can aggravate the symptoms of asthma and chronic lung disease. Column headings:...

"Freshwater plant and animal pests can have significant negative impacts on ecosystem health by reducing indigenous biodiversity through predation and competition, and destabilising aquatic habitats. Freshwater plant pests can cause economic losses through blocking water intakes for hydroelectricity generation, impeded drainage or irrigation. In addition,...

Other human-made sources – such as aviation, forestry, and non-combustion industrial activities (eg grinding and crushing) – generally emit relatively small amounts of key air pollutants. Comparing their contribution to air pollution helps us understand the pressures they place on our air quality. Other human-made sources of air pollution include but are...

Marine non-indigenous (exotic) species arrive in New Zealand waters on the hulls of international vessels (biofouling) or in discharged ballast waters. Some have little impact or cannot survive in New Zealand waters; others have a negative impact on our native habitats and species and become pests. They can compete with, and prey on, indigenous species,...

A three-day rainfall measurement covers a single sustained rain event or a series of shorter events over a three-day period. Such measurements help us understand and prepare for flooding or rain-induced slips that could cause damage. Further information can be found in: Tait, A, Macara, G, & Paul, V. (2014) Preparation of climate datasets for the 2015...

"Freshwater plant and animal pests can have significant negative impacts on ecosystem health by reducing indigenous biodiversity through predation and competition, and destabilising aquatic habitats. Freshwater plant pests can cause economic losses through blocking water intakes for hydroelectricity generation, impeded drainage or irrigation. In addition,...