This data set reports on trends for 15 coastal and estuarine water quality measures, grouped below by type, monitored at sites across Aotearoa New Zealand between 2006 and 2020:

  • nutrient – ammoniacal nitrogen, nitrate-nitrite nitrogen, total nitrogen (unfiltered), dissolved reactive phosphorus, and total phosphorus (unfiltered)
  • microbiological – faecal coliforms, Enterococci, and chlorophyll-a
  • optical – visual clarity, turbidity, and suspended solids (inorganic and organic)
  • physico-chemical – dissolved oxygen, pH, salinity, and temperature.

We present trends for the period 2011 to 2020.

Coastal and estuarine ecosystems are affected by changes in water quality.

Nutrients
The two main nutrients of concern in coastal and estuarine ecosystems are nitrogen and, to a lesser degree, phosphorus. An overload of nutrients (eutrophication) can lead to algal blooms that can kill marine life by depleting oxygen levels. Some bloom-forming algal species also contain toxins that can harm marine life, and can pass through food chains to humans (for example, via shellfish poisoning).

Microbiological
Abundant Enterococci _and faecal coliform bacteria indicate the possible presence of human faecal pathogens in coastal waters and represent the risk of infectious disease. Chlorophyll-_a is a measure of phytoplankton biomass and is a primary indicator of eutrophication.

Optical
High suspended sediment concentrations are associated with estuarine and coastal sedimentation, reduced light levels in benthic (seabed) environments, and reduced feeding rates and health of estuarine and coastal animals (Lowe et al., 2015). Visual clarity and turbidity are monitored because light affects primary production, plant and animal distributions and ecological health, aesthetic quality, and recreational values (Davies-Colley et al., 2003).

Physico-chemical
Dissolved oxygen is fundamental to supporting marine life. Low levels of dissolved oxygen can have adverse effects on aquatic fauna, from reduced growth rates to death from lack of oxygen (Tomasetti & Gobler, 2020). Decreased pH results from the absorption of CO2 from the atmosphere by seawater but can also reflect local processes caused by eutrophication (Cai et al., 2011; Fraser et al., 2021). Changes in the pH of seawater can have harmful effects on marine life, impacting chemical communication, reproduction, and growth. The building of skeletons in marine organisms is particularly sensitive to acidity, so acidification (lower pH) of sea waters can be harmful for organisms such as shellfish and corals (Fabry et al., 2008). Salinity provides information on the freshwater content of coastal waters. Water temperature is important as it controls biochemical processes and affects the balance of parameters such as dissolved oxygen levels. As a result, seawater temperature determines distributions of many marine plants and animals (Kleisner et al., 2017).

Adapted by Ministry for the Environment and Statistics New Zealand to provide for environmental reporting transparency. Dataset used to develop the "Coastal and estuarine water quality, trends" indicator (available at ++Coastal and estuarine water quality | Stats NZ++).

Layer ID 111131
Data type Vector point
Feature count 3024
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Lake water quality, 2009–13

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Creative Commons Attribution 3.0 New Zealand

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13476
94
Added
17 Feb 2016

This dataset was first added to MfE Data Service on 17 Feb 2016.

"The Lake Trophic Level Index (TLI) characterises the life supporting capacity of a lake based on nutrient enrichment. In general, the higher the TLI score, the poorer the water quality in the lake. Lakes with extremely poor quality are rarely suitable for recreation and provide poor quality habitat for aquatic species.
Care should be taken when interpreting these results. Monitored lakes consist of about 4 percent of all New Zealand lakes, and programmes may focus on those that have poor water quality or are at risk due to the type of land use in their catchment.
After checking for data consistency, the lakes considered suitable for national comparison are sparsely and unevenly distributed, with gaps in the Manawatu, Taranaki, Tasman, Marlborough, Otago, and West Coast regions. The lakes considered in the analysis are located mainly in Northland, Bay of Plenty, Hawke’s Bay, and Canterbury.
This dataset relates to the ""Lake water quality: trophic level index"" measure on the Environmental Indicators, Te taiao Aotearoa website.
"

Layer ID 53310
Data type Vector point
Feature count 86
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Occurrence of non-native species in monitored ports

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Creative Commons Attribution 3.0 New Zealand

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10631
39
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

The number of exotic species observed in New Zealand's monitored ports of first entry for international vessels

Layer ID 52749
Data type Vector point
Feature count 11
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Water poppy

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Creative Commons Attribution 3.0 New Zealand

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10110
13
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52746
Data type Vector point
Feature count 36
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Yellow Flag

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Creative Commons Attribution 3.0 New Zealand

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10062
18
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52745
Data type Vector point
Feature count 61
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Water net

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Creative Commons Attribution 3.0 New Zealand

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11578
14
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52744
Data type Vector point
Feature count 16
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Water lettuce

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Creative Commons Attribution 3.0 New Zealand

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9935
14
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52743
Data type Vector point
Feature count 3
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Water hyacinth

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Creative Commons Attribution 3.0 New Zealand

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You must attribute the creator in your own works.

12077
17
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the ""Freshwater pests"" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52741
Data type Vector point
Feature count 10
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Tench

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Creative Commons Attribution 3.0 New Zealand

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10238
21
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52740
Data type Vector point
Feature count 128
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Freshwater pests: Reed sweetgrass

Licence

Creative Commons Attribution 3.0 New Zealand

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10449
27
Added
11 Jan 2016

This dataset was first added to MfE Data Service on 11 Jan 2016.

"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, pests can affect the suitability for recreational activities.
This dataset relates to the "Freshwater pests" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Layer ID 52731
Data type Vector point
Feature count 108
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed
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