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  • Added 19 Apr 2017

This datasets contains the underlying bathymetry used to delineate the draft estuarine boundaries

The research has been undertaken to provide a stronger foundation for ensuring that examples of all types of historically rare ecosystems are legally secure for conservation under either Crown or private tenure, and to ensure that management actions are appropriate to guarantee the retention of these unique environments and the biota they contain.

In New Zealand, the heterogeneity of the landscape has resulted in a diverse array of small, often widely dispersed, rare ecosystems that tend to occur in extreme, typically treeless, environments. As such they have been rare since before humans arrived, which is the rationale for the term 'historically' rare. Such ecosystems may contribute to biodiversity by having very high fine-scale native species richness (e.g. ephemeral wetlands, coastal turfs), high endemism (e.g. ultramafic areas, karst specialised lifeforms (e.g. halophytes in salt pans, tropical taxa in geothermal areas)).Further, such ecosystems now may provide important refuges for native plant and animal species within highly modified landscapes.

Estuaries are where fresh water from rivers mixes with salt water. They are formed where the underlying or adjacent topography constrains the mixed water throughout the tidal cycle. They are formed behind barriers such as sand spits and coastal embayments, at river mouths, in drowned river valleys with gently sloping substrates, and even in fjords. Their inland limit is where salinity reaches a dilution of 5% of the marine concentration (Clarkson et al. 2003). Sheltered, northern estuaries can support mangroves (Avicennia marina).

Estuaries are widespread in New Zealand (more so than lagoons) and occur in about 40 ecological regions from Northland to Fiordland.

Maintaining threatened rare ecosystems is an eight-year research programme (from July 2005), funded by the Foundation for Research, Science and Technology (FRST).


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TagsEstuarine, Rare Ecosystems, Wetlands
RegionsNew Zealand
MetadataISO 19115/19139, Dublin Core

Technical Details

Layer ID 31517
Data type Vector polygon
Feature count 64158
Attributes Bath_Chart, SegFlow_5m, Bath_Source, Estuarine_2m_depth_ID, EST_TYPES, Ed_Comment, Estuarine_4m_depth_ID, Bath_DRVAL1, Bath_DRVAL2, Solution_2m, Estuarine_3m_depth_ID, Solution_4m, Estuarine_1m_depth_ID, Hectares, SegFlow_3m, SegFlow_1m, Estuarine_5m_depth_ID, SegFlow_4m, EST_Source, CreatedDate, ModifiedBy, EST_NAME, Solution_5m, Solution_3m, ModifiedDate, CreatedBy, SegFlow_2m
Services Vector Query API


Added19 Apr 2017
Last updated19 Apr 2017
Revisions 1 - Browse all revisions
Current revision Imported on April 18, 2017 from Esri JSON in NZGD2000 / New Zealand Transverse Mercator 2000. 3 geometries modified to be OGC compliant. Changelog.
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