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6.0 Future directions for New Zealand marine classification

During 2000, the Ministry for the Environment ran a series of workshops to assess options for developing a comprehensive marine classification system/spatial framework that has a predictive capacity. Work is now proceeding on the development of a marine parallal to Land Environments New Zealand (LENZ). LENZ divides the terrestrial landscape into ecosystem units by computer analysis of the environmental variables that constrain biotic distributions (i.e. a number of climate and landform geological variables). The process of defining unit boundaries is highly automated and considered objective, provided that the contributing data sets are scientifically robust and sufficiently comprehensive.

The marine equivalent would use key physical parameters that determine/influence biotic composition, patterns and processes. A major constraint to developing a comprehensive system for the marine environment is the nature of marine environment data sets. There are gaps, not all data sets are digitized; and there are accessibility problems with some of the data sets. Froude's (2000) review of marine environment data sets in New Zealand shows that there is a large amount of marine data held by a variety of agencies. The various physical datasets could be used in devising the classification, while the biological datasets (including fisheries) could be used to test the validity of such a classification.

The NIWA estuarine classification development process is using physical parameters that affect both estuaries and the open coast, as well as some parameters that are unique to estuaries. The Australian estuarine classification by Digby et al (1999) is being used as a model for the development of the NIWA estuarine classification system.

A gap in New Zealand marine classification, especially in comparison to other countries, is a standardized national classification system for describing marine habitats and communities. This is needed for indicator monitoring and reporting. Options for addressing this include:

• Refining the marine hydrosystem component in the UNEP GRID New Zealand wetland classification to extend its coverage to deeper habitats. The advantage would be that a lot of work has already gone into developing a logical ecologically driven standard classification system for all aquatic hydrosystems and this would facilitate continuity in classification for all aquatic systems. The disadvantage is that the open coast marine component of the UNEP-GRID classification is relatively poorly developed compared to the palustrine and estuarine components. This could be addressed if those with appropriate skills were deployed to the task.
• Building on the various local habitat classifications already in use by agencies such as the Auckland Regional Council. The advantage of this is that experts have already been involved in developing these classifications. The disadvantage is that these classifications have been designed to fit a local area and so may not readily expand to provide a national classification.

Biogeographical spatial frameworks can be useful for assessing the representativeness of marine protected areas. There are several relatively comprehensive New Zealand options ( King et al (1985), Walls & Mc Crone (in prep)) that could be used for this purpose.