Tongapōrutu Estuary (at Hills Road baches)
The Tongapōrutu Estuary is a long, shallow and short resident time tidal river estuary and is one of the few areas in Taranaki where indigenous forest adjoins the coastline. The estuary contains important breeding areas for native fish and the intertidal flats support a range of shellfish and other invertebrates. Tongapōrutu Estuary and the adjacent wetland are included in the Council’s Key Native Ecosystem programme in recognition of the area’s high ecological value. It is also significant for Ngāti Tama with a number of pā sites along its riverbanks. The upstream catchment is dominated by mixed native forest (82%) as well as sheep and beef farmland (16%).
The estuary is vulnerable to the impacts of sedimentation due to the catchment being erosion prone and the high proportion of muddy sediments in the mid-upper reaches of the estuary.
Monitored site results
This dashboard shows information on the data collected by the regional councils and unitary authorities for the Estuary health scientific indicators, click the tiles for more information:
Estuary stressor
Mud content information
What do the grades mean?
Mud content refers to the amount of fine silt and clay particles (collectively called ‘mud’) that are present in the estuary sandflats. This figure shows (mean) annual mud content measured at the monitoring site. The annual values are assessed against custom, national guidelines that indicate increasingly negative impacts on the macrofaunal community.
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≤3%
Ecology is not negatively impacted.
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3-10%
The diversity of the macrofauna community is slightly reduced.
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10-30%
The diversity of the macrofauna community is reduced and less resilient to disturbance.
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30-60%
The macrofauna community is unbalanced and dominated by a small number of tolerant species.
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>60%
The macrofauna community is degraded.
Zinc information
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Copper information
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Lead information
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Arsenic information
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Mercury information
View results alongside National guidelines:
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Cadmium information
View results alongside National guidelines:
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Chromium information
View results alongside National guidelines:
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable
Nickel information
View results alongside National guidelines:
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What do the grades mean?
This figure shows the (mean) annual contaminant concentration measured in the sediments of the monitored site. The annual values are assessed against the ANZG 2018 guidelines by default, and you can choose to view them assessed against several additional, more conservative guidelines. All of the guidelines show how likely it is that the contaminant is having negative ecological impacts. See the Contaminants factsheet for more information.
- Ecological impacts unlikely
- Ecological impacts possible
- Ecological impacts probable