World Lakes Data

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.

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 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....

When nutrients accumulate in lakes (referred to as ‘nutrient enrichment’) above certain levels, they can make the lakes murky and green with algae, and lower oxygen levels. Lakes with extremely poor water quality are rarely suitable for recreation and provide poor habitats for aquatic species.

Percentile calculations for the following parameters are provided:
Trophic Level Index 3 (TLI)
Chlorophyll-a (CHLA)
Bottom-water dissolved oxygen (DObottom)
Ammoniacal nitrogen (NH4N)
Oxidised nitrogen (NO3N)
Total nitrogen (unfiltered) (TN)
Dissolved reactive phosphorus (DRP)
Total phosphorus (unfiltered) (TP)

For more information please see:
Larned, S, Snelder, T, Unwin, M, McBride, G, Verburg, P, McMillan, H (2015).Analysis of Water Quality in New Zealand lakes and Rivers: data sources, data sets, assumptions, limitations, methods and results. NIWA Client Report no. CHC2015-033. Available at data.mfe.govt.nz/x/DDui3u from the Ministry for the Environment dataservice.

This dataset relates to the "Lake water quality: Trophic Level Index" measure on the Environmental Indicators, Te taiao Aotearoa website.

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...

When nutrients accumulate in lakes (referred to as ‘nutrient enrichment’) above certain levels, they can make the lakes murky and green with algae, and lower oxygen levels. Lakes with extremely poor water quality are rarely suitable for recreation and provide poor habitats for aquatic species.

Trends in the following parameters are provided:
Trophic Level Index 3 (TLI)
Chlorophyll-a (CHLA)
Bottom-water dissolved oxygen (DObottom)
Ammoniacal nitrogen (NH4N)
Oxidised nitrogen (NO3N)
Total nitrogen (unfiltered) (TN)
Dissolved reactive phosphorus (DRP)
Total phosphorus (unfiltered) (TP)

For more information please see:
Larned, S, Snelder, T, Unwin, M, McBride, G, Verburg, P, McMillan, H (2015).Analysis of Water Quality in New Zealand lakes and Rivers: data sources, data sets, assumptions, limitations, methods and results. NIWA Client Report no. CHC2015-033. Available at data.mfe.govt.nz/x/DDui3u from the Ministry for the Environment dataservice.

This dataset relates to the "Lake water quality: Trophic Level Index" measure on the Environmental Indicators, Te taiao Aotearoa website.

Adapted by Ministry for the Environment and Statistics New Zealand to provide for environmental reporting transparency. Dataset used to develop the "Lake water quality" indicator (available at www.stats.govt.nz/indicators/lake-water-quality).

We report on eight biological, chemical, and physical lake water quality attributes based on spatially modelled data: trophic level index (TLI), chlorophyll-a, E. coli, total phosphorus, total nitrogen, ammoniacal nitrogen, nitrate-nitrogen, and clarity.

We also report median values and TLI and NOF bands for selected attributes using spatially modelled data with predictions for 3,813 lakes in New Zealand that are larger than 1 hectare.

High concentrations of the measured biological and chemical attributes or low clarity indicates poor habitats for some species of animals and plants, risks for human recreation, potential toxic effects on aquatic life, and poor overall lake health.

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 environment.govt.nz/publications/environment-aotea....

Adapted by Ministry for the Environment and Statistics New Zealand to provide for environmental reporting transparency. Dataset used to develop the "Lake water quality" indicator (available at www.stats.govt.nz/indicators/lake-water-quality).

We report on eight biological, chemical, and physical lake water quality attributes based on measurements made at monitored lake sites: trophic level index (TLI), chlorophyll-a, E. coli, total phosphorus, total nitrogen, ammoniacal nitrogen, nitrate-nitrogen, and clarity.

For all attributes we report on the median values for monitored sites during the period 2016–20. For selected attributes we also report:

• how these values compare to the National Objectives Framework (NOF) bands related to ecosystem health (trophic level), toxicity, and E. coli (MfE, 2020)
• a comparison of NOF and trophic level index (TLI) bands at monitored sites with the proportion of human modified landcover in the upstream catchment area

High concentrations of the measured biological and chemical attributes or low clarity indicates poor habitats for some species of animals and plants, risks for human recreation, potential toxic effects on aquatic life, and poor overall lake health.

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 environment.govt.nz/publications/environment-aotea....

Adapted by Ministry for the Environment and Statistics New Zealand to provide for environmental reporting transparency. Dataset used to develop the "Lake water quality" indicator (available at www.stats.govt.nz/indicators/lake-water-quality).

We report on eight biological, chemical, and physical lake water quality attributes based on measurements made at monitored lake sites: trophic level index (TLI), chlorophyll-a, E. coli, total phosphorus, total nitrogen, ammoniacal nitrogen, nitrate-nitrogen, and clarity.

For selected attributes we report trends based on measurements made at monitoring sites over a 10-year period (2011–2020).

High concentrations of the measured biological and chemical attributes or low clarity indicates poor habitats for some species of animals and plants, risks for human recreation, potential toxic effects on aquatic life, and poor overall lake health.

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 environment.govt.nz/publications/environment-aotea....

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.