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4.0 New Zealand classification systems and spatial frameworks

4.1 Classification systems and spatial frameworks reviewed

Section 7 contains the metadata sheets for the New Zealand classification systems and spatial frameworks that were reviewed. Section 8 summarises key characteristics of some of these systems to facilitate comparisons between them. Aspects included in this table include:

New Zealand coastal and marine environment classification systems and spatial frameworks can be grouped as follows:

4.2. Trends in New Zealand coastal and marine classification systems and spatial frameworks

4.2.1 Bioregional/biogeographic spatial frameworks

The three spatial frameworks listed in 4.1 reflect a combination of environmental attributes that affect biota distribution and patterns. They have been compiled by experts defining areas that are considered to have some commonality in the expression of environmental attributes.

At the broadest scale is the biogeographical regions framework from Knox (1975). This divided New Zealand shelf waters, including the major offshore islands groups, into six biogeographical regions. More detailed divisions are in King et al (1985) and the Department of Conservation (in prep). King et al (1985) uses three tiers:

Each district and region is mapped and described.

A major use of biogeographical spatial frameworks would be to assist in the development of a comprehensive and representative network of marine protected areas. Spatial frameworks may also assist agencies to identify areas where certain types of damaging activity are not allowed.

4.2.2 Wetland classifications using the Ramsar definition of wetland

These classification systems use the broad definition of wetland from the Convention on Wetlands of International Importance (Ramsar Convention). This definition is used internationally and is the basis for a large number of classification systems worldwide. About 120 countries including NZ are contracting parties to the convention.

The definition of wetland used in the Convention is as follows:

"...wetlands are areas of marsh, fen, peatland, or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh , brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres."

The original rationale behind this very broad definition was a desire to include all the "wetland" habitats of migratory water birds. With the increasing importance of the Convention on Biological Diversity, the definition of wetland (and the associated classification systems have been progressively expanded to include coral reefs, geothermal systems, karst and other underground wet systems.

The classification systems in this category are habitat classification systems. They result in homogeneous units that can be repeated across seascapes. These classification systems address freshwater (palustrine, lacustrine and riverine) hydro systems as well as estuarine and shallow coastal waters (marine).

The Ramsar classification system provides a very broad framework to assist with the rapid identification of the main wetland types. Unlike most other environmental classification systems used in New Zealand this system is designed to classify wetlands globally, especially in situations where there is little information. This classification system is the basis for the global Ramsar database which contains approximately 1000 formally identified wetlands of international significance. In New Zealand five wetland sites have been formally designated and 104 sites have been formally identified as being of international significance. Further information is in Froude and Beanland (1999).

The Environmental Council/Thompson wetland classification system was developed as part of the New Zealand Wetland Management Policy. This system has been used to classify sites in the Wetlands of Ecological and Regional Importance Database that contains more than 3000 classified wetlands. This system has focused on palustrine and estuarine wetlands. It is a simple hierarchical system that has been unevenly developed. Further information is in Froude and Beanland (1999).

The most recent of the classification systems using the Ramsar definition of wetland is the UNEP GRID NZ Wetland Classification. This is the most comprehensive of these classification systems developed so far in New Zealand. While the estuarine component of the classification system has been piloted, more work is still required for the marine component of the classification.

4.2.3 Physical classifications for estuaries

The third grouping of New Zealand marine environment classification systems is the physical classification systems for estuaries. McClay's simple estuary classification was applied to 301 estuaries throughout New Zealand. The Hume & Herdendorf (1988) system divides estuaries into 16 types based on various geomorphic and oceanographic characteristics of the estuary.

The NIWA estuary classification will, once developed, be the most comprehensive of the estuary physical classifications. Classification development is using a top-down approach (identification of dominant processes) and a bottom up approach (to test the validity of the classification).

4.2.4 Local classifications for physical attributes and/or habitats/communities

Section 8, part two of this report identifies key attributes for 4 marine environment classification systems developed for Auckland Regional Council. These systems, based on physical attributes and habitats, have been developed for a variety of purposes and so have different structures and emphases. None have these systems have been extended for use at a national level.