Macroinvertebrates, also known as macrofauna, are the animals living on top of or within the sediment. The abundance, composition and diversity of macrofauna are commonly-used indicators of estuarine health.
Usage guide: Toggle between tabs to see different macroinvertebate monitoring summaries. Click and drag the year slider on each map (if available) to see change over time, and hover over map data to see specific values. The chart below the map displays each sites' data temporally, hovering over lines will also show specific values and highlight that site on the map.
The AZTI’s Marine Biotic Index (AMBI) is one of several marine biotic indices that assesses estuarine health based on the types and numbers of macrofauna and their known tolerances to environmental stress. Lower AMBI values generally indicate better ecological conditions. Values are rated against thresholds derived from the New Zealand Estuary Trophic Index.
See Stevens & Robertson 2012 and Stevens 2022 for technical methods, data tables, and further information
Benthic health models have been developed to track the health of New Zealand estuarine benthic communities in response to two key coastal stressors: sedimentation and heavy metal contamination. The mapped results below indicate the impact of heavy metal contamination on the benthic health of Te Whanganui-a-Tara relative to other estuarine sites in New Zealand.
See Cummings et al. 2021 for technical methods, data tables, and further information
Benthic ecology status can be assessed using a Traits-based index (TBI) that indicate the levels of community functional redundancy and the degree of site degradation.
See Cummings et al. 2021 for technical methods, data tables, and further information
Species richness is measured by counting the number of different species of invertebrates present in a sample. High richness can indicate greater diversity.
Note that different surveys use varying sample sizes and taxonomic
classifications.
See Stevens & Robertson 2012, Stevens 2018a, Stevens 2018b and Stevens 2022 for technical methods, data tables, and further information