Marine Habitat Assessment Decision Support Tool (MarHADS)


To provide a tool that would assist regional council resource managers and decision makers to critically assess the relative state and value of coastal habitats and environments using established criteria that can be applied consistently across regions and nationally.


Regional councils have an important role in the undertaking the preservation of natural character and protection of indigenous vegetation and fauna. However this has been severely hampered by a lack of information on the values and sensitivity of coastal ecosystems.

There has been no nationally accepted and scientifically robust guidelines on how to determine which areas are significant and therefore should be protected, and existing guidelines for fresh water or terrestrial ecosystems do not readily apply to marine ecosystems.

The MarHADS tool was developed for the Regional Council Coastal Special Interest Group (SIG) to provide a consistent and robust method of assessing marine habitat values. There are considerable benefits to be gained from having a nationally consistent methodology and approach for the identification of important ecosystems that is underpinned by robust science.

In December 2008 regional council staff from around New Zealand identified that the MarHADS tool must:

  • Provide an indication of the relative proportion of a habitat on a regional and national basis
  • Incorporate assessment of threats to marine habitats
  • Incorporate assessment of the goods and services provided by marine habitats
  • Take into account any threatened and endangered species occurring within a habitat
  • Include some measure of the degradation of habitats
  • Incorporate measure of uncertainty
  • Be applicable to a wide range of coastal environments nationally
  • Be able to take into account the limited resources and paucity of data available to many regional councils
  • Uses information regional councils have, but allows for new information – target future sampling
  • Prevent data intensive areas from ranking highest
  • Be robust and defendable in court


To meet these needs the tool incorporates five explicit components about marine habitats (See Model diagram below). These are:

  1. The quantity of habitat – the actual and relative size of the habitat in question on local, regional, bioregional and national scales.
  2. Habitat vulnerability – this includes likely threats, their scale and functional impact, as well as the resilience of the habitat to those particular threats, the recovery timescale once the threat is removed and the level of uncertainty in assessments of these factors given the state of knowledge about them.
  3. The nationally threatened and at risk species that may occur within particular habitats.
  4. Habitat quality as assessed by the number of invasive species, water quality, sediment quality, the degree to which the expected biotic assemblage remains intact, and an overall assessment of the degree that expected ecosystem features and functions remain in operation.
  5. The level of regulatory, provisioning, and non-consumptive ecosystem goods and services provided by marine habitats.

Each component is described and assessed via a specific sheet in the MS Excel template. A Master sheet (see image below) at the beginning is used to input critical parameters (region and bioregion) that are used to populate other parts of the tool with appropriate information.

 MarHADS Interface2


The model allow for multiple assessments to be undertaken in a region and to assist in comparing the output from multiple assessments, the information in the summary dashboard has been rearranged on a comparison sheet. 

State of Development Released and updated

Development Contact


Outcome Areas Environmental
Management Domains Coastal
Subdomains Ecosystem/Habitat
Intended End Users
  • Researcher
  • Regional Council Scientist
  • Policy Analyst
Steady State or Dynamic Unknown

Input & Output Data


Open/Closed Source Closed Source
Licence Type Non-Comercial Use only

User Information

Operating Systems MS Windows
Software Needed MS Excel
User Interface Other (please specify) Runs in MS Excel forms/linked sheets
Ease of Use Easy

Technical Considerations

Model Structure

MarHADS components

Keywords Marine Habitat,

Decision Support Systems for coastal risk assessment and management;

A decision-support tool to facilitate discussion of no-take boundaries for Marine Protected Areas during stakeholder consultation processes;

Key References

MacDiarmid A.B.; Taylor, P.; Carbines, M.; Hewitt, J.; Bolton-Ritchie, L.; Maharadz  Smith, A.; Townsend, M.; Thrush, S.; Walker, J. (2011). Marine Habitat Assessment Decision Support (MarHADS) Tool - Background and Operating Instructions. Produced for the NZ Regional Council Coastal Special Interest Group, Envirolink Contract NIWX0803, 25 pp. (PDF)

Associated Case Studies

MarHADS - Applied in the Auckland Council Region

The tool was developed with the aim of bringing some form of standardisation to the assessment and comparison of marine habitat values within regions and at a national level.