World Freshwater Data - Page 5

This dataset contains ten lake water quality variables based on measurements made at monitored lake sites: chlorophyll-a, nitrate-nitrogen, total nitrogen, ammoniacal nitrogen, dissolved reactive phosphorus, total phosphorus, Escherichia coli, water clarity, and lake trophic level index (TLI3 and TLI4). This dataset includes: - Median values for the period 2013 to 2017 - For selected indicators, how these values compare to the National Objectives Framework (NOF) (MfE, 2017) bands related to ecosystem health When nitrogen and phosphorus accumulate above certain concentrations in lakes (referred to as ‘nutrient enrichment’), they can stimulate excessive growth of algae and cyanobacteria. Chlorophyll-a is a measure of the phytoplankton (algae) biomass. The lake trophic level index (TLI) indicates the health of a lake based on concentrations of three variables:
· total nitrogen
· total phosphorus
· chlorophyll-a.
Water clarity is a measure of underwater visibility. Lakes with poor clarity and TLI are poor habitats for some species of animals and plants, and they may not be suitable for recreation. Ammoniacal nitrogen can be toxic to aquatic life if concentrations are high enough.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Summary report available at: www.mfe.govt.nz/publications/fresh-water/water-qua....

This dataset measures groundwater quality in New Zealand’s aquifers based on measurements made at monitored sites. Many factors influence the quality of our groundwater. Nitrogen, which occurs naturally in groundwater, can increase in concentrations due to agricultural and urban land use, and infrastructure such as waste treatment plants. High concentrations of nitrate-nitrogen in groundwater can affect human health and the quality of surrounding rivers and lakes that receive inflows from groundwater. Ammoniacal nitrogen can cause an undesirable smell that may make groundwater unsuitable for drinking water. Natural processes in groundwater can convert nitrate-nitrogen into ammoniacal nitrogen or other forms under some chemical conditions. Surplus phosphorus drains (leaches) into groundwater as dissolved reactive phosphorus. Too much nitrate-nitrogen, ammoniacal nitrogen, and phosphorus can lead to excessive plant and algae growth where groundwater flows into surface water. E. coli in groundwater is measured in colony forming units (cfu) and can indicate the presence of pathogens (disease-causing organisms) from animal or human faeces. The pathogens can cause illness for anyone who ingests them.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Submerged plants are good indicators of the ecological quality of lakes. Because they are attached to the bed of lakes, submerged plants are easy to observe and identify, and they are unable to move away from environmental changes. The plant species found within lakes can tell us about their level of habitat degradation and exotic weed invasion.

The file contains Lake submerged plant index scores for each sampling occasion.

This indicator reports on six measures of lake water quality based on spatially modelled data for:

• chlorophyll-a
• total nitrogen
• ammoniacal nitrogen
• total phosphorus
• water clarity
• trophic level index (TLI3).

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For these measures we report on:

• modelled median values for the period 2013–17
• for selected measures, how these values compare to the National Objectives Framework (NOF) bands related to ecosystem health (MfE, 2017).

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This indicator includes spatial predictions for 3,802 of 3,820 lakes in New Zealand (majority of New Zealand lakes that are larger than 1 hectare), based on measurements at 61–104 lake sites (the number of sites differs by measure).

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

The most recent assessment of ecological condition of 295 lakes in New Zealand assessed on at least one occasion between 1991 and 2019 was measured using the lake submerged plant index (LakeSPI).

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

This indicator measures groundwater quality in New Zealand’s aquifers and how it is changing over time, based on measurements made at monitored sites. We report on nitrate-nitrogen, ammoniacal nitrogen, dissolved reactive phosphorus, chloride, conductivity and Escherichia coli (E. coli) including:

• trends in concentrations for 10-year (2009–18) and 20-year (1999–2018) periods.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

We report on the conservation status and most recent change in status of indigenous (native), resident (breeds in New Zealand) freshwater fish and invertebrates that have been assessed by New Zealand Threat Classification System (NZTCS) expert panels.
More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

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This dataset measures how water quality in New Zealand’s rivers is changing over time. It contains nine parameters of water quality based on measurements made at monitored river sites in years 1990-2017:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Summary report available at www.mfe.govt.nz/publications/fresh-water/water-qua....

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

​

This dataset contains ten parameters of water quality based on measurements made at monitored river sites:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Ammoniacal nitrogen (adjusted)
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index

This dataset includes:

• Median values for the period 2013 to 2017
• for selected indicators, how these values compare to the National Objectives Framework (NOF) (MfE, 2017) bands related to ecosystem health and human health for recreation, and to expected concentrations in natural conditions, as shown by the default guideline values in the Australian and New Zealand guidelines for fresh and marine water quality (ANZG, 2018)

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Summary report available at www.mfe.govt.nz/publications/fresh-water/water-qua....

This dataset summaries backpack electric fishing observations from the New Zealand Freshwater Fish Database for the period 1998 - 2018. It provides the locations and scores for Fish Index of Biotic Integrity (IBI) (including sub-metric scores).

Technical report available at www.mfe.govt.nz/publications/environmental-reporti....

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.