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Coastal ecosystem health

Waikato progress indicators – Tupuranga Waikato
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Waikato Progress Indicators - tupuranga Waikato

Image - WPI coastal habitats - family in coastal environmentCOASTAL ECOSYSTEM HEALTH

 WPI - no change icon   NO SIGNIFICANT CHANGE

This indicator shows that most of the monitored sites are moderately healthy, and at most sites there were only slight changes in estuarine ecosystem health between 2012 and 2021. There is not yet enough data to analyse trends statistically.

Why is this indicator important?

This indicator describes the diversity of animals that live in our estuaries. Estuaries are an important part of our coastal marine area. They are productive ecosystems, but are also one of the most sensitive coastal areas, and are at risk from human activities.

We currently monitor the sediment-dwelling animal communities in four estuaries: the southern Firth of Thames, Whāingaroa (Raglan) Harbour, Tairua Harbour and Coromandel Harbour. Sediment-dwelling animals (such as shellfish, crustaceans and marine worms) are important in estuaries because they cycle nutrients between the sediment and water, stabilise and rework sediments, and are an important food resource for birds, fish, and crabs. The animal community characteristics are summarised by a Traits Based Index that makes use of the animals’ biological traits. Biological traits are the physical and behavioural characteristics that define a particular species (e.g. body size, mobility, feeding behaviour).

The Traits Based Index (TBI) tells us about the health of our estuaries. It ranges between zero and one, with one being most healthy and zero being least healthy. We can use the TBI to track the health of our estuary sites over time, and to compare the health of different estuaries.

Ecosystem health at sites in monitored estuaries

TBI scores range between zero and one, with one being most healthy and zero being least healthy.

    TBI score (a measure of ecosystem health)
Estuary Site 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Firth of Thames Gun Club 0.380 0.310 0.420 0.344 0.344 0.306 0.353 NA NA NA
Kaiaua 0.340 0.330 0.410 0.381 0.395 0.362 0.489 NA NA NA
Kuranui Bay 0.350 0.270 0.360 0.301 0.268 0.414 0.381 0.245 0.231 0.259
Miranda 0.420 0.340 0.370 0.334 0.348 0.419 0.395 0.268 0.358 0.334
Te Puru 0.300 0.310 0.260 0.301 0.452 0.424 0.348 NA NA NA
Whaingaroa (Raglan) Harbour Haroto Bay 0.260 0.350 0.330 0.320 0.287 0.278 0.264 NA NA NA
Okete Bay 0.570 0.450 0.450 0.456 0.508 0.400 0.424 0.367 0.428 0.433
Ponganui Creek NA NA NA NA 0.541 0.584 0.706 NA NA NA
Te Puna Point NA NA NA NA 0.485 0.414 0.452 NA NA NA
Whatitirinui Island 0.490 0.590 0.590 0.565 0.621 0.513 0.353 0.296 0.706 0.565
Kaitoke Bay NA NA NA NA NA NA NA 0.287 0.311 0.296
Tairua Harbour Gumdigger Gully 0.350 0.380 0.290 0.344 0.296 0.339 0.296 0.245 0.301 0.282
Manaia Road 0.470 0.470 0.340 0.386 0.419 0.409 0.419 0.372 0.334 0.329
Oturu Sream 0.340 0.360 0.370 0.447 0.334 0.358 0.315 0.381 0.339 0.325
Pauanui 0.570 0.440 0.410 0.438 0.532 0.386 0.381 0.461 0.489 0.471
Pepe Inlet 0.400 0.370 0.330 0.381 0.353 0.353 0.339 0.353 0.306 0.339
Coromandel Harbour Awakanae Stream NA NA NA NA NA NA NA 0.513 0.711 0.565
Brickfield Bay NA NA NA NA NA NA NA 0.499 0.565 0.522
Coromandel Town NA NA NA NA NA NA NA 0.386 0.306 0.400
McGregor Bay NA NA NA NA NA NA NA 0.362 0.273 0.282

Waikato Progress Indicators - Coastal health graph

To provide a broad, summary indication of overall regional coastal ecosystem health, the average of the results from each site are shown below.

Average Traits Based Index (TBI) scores for monitored sites

WPI - Coastal ecosystem health graph

 

Year

Regional index

(average of all sites)
2012 0.40
2013 0.38
2014 0.38
2015 0.38
2016 0.41
2017 0.40
2018 0.39
2019 0.36
2020 0.40
2021 0.39

What is this indicator telling us? 

  • Many of the sites are moderately healthy (having a TBI score between 0.3 and 0.4), some are in poor health (having a TBI score less than 0.3), and some are in relatively good health (having a TBI score greater than 0.4).
  • At most sites, there were only slight changes in the TBI, and therefore in estuarine health, between 2012 and 2021. We expect the TBI score to vary slightly from year-to-year due to natural variability. There is not yet enough data to analyse trends statistically.

DATA SOURCE AND SUPPORTING INFORMATION

Data sourced from Waikato Regional Council’s Regional Estuary Monitoring Programme: https://www.waikatoregion.govt.nz/regional-estuary-monitoring-programme/

Update details: Monitoring is carried out on an annual basis.

Customised data request requirements: Request is for the Traits Based Index calculated for sites in the Regional Estuary Monitoring Programme.

DATA AVAILABILITY – OTHER THAN WAIKATO REGION:

Territorial Authority (TA) disaggregation: No

Other regions: No

New Zealand: No

Other countries/ Organisation for Economic Co-operation and Development (OECD): No