Fisheries of New Zealand is intended primarily as a reference. It provides graphical summaries of data from New Zealand's fisheries but does not attempt to answer the many "why" questions that arise when examining these summaries.

Fisheries of New Zealand focusses on:

  • segmenting the data in ways that reflect the underlying structure of commercial fishing activities; and
  • providing a consistent set of summaries of the patterns and trends in the data that are applied to contrasting fishing activities.

There are numerous and diverse causes for the changes seen in the data summaries including regulatory, economic and biological drivers. Fisheries of New Zealand is not intended as a scientific assessment of any of the fisheries included and does not provide explanatory analyses of the reasons for the patterns and changes seen. The factors affecting commercial fishing activities vary from area to area, species to species and method to method. For some segments descriptive text of the recent trends is included.

Segment hierarchies

Fisheries of New Zealand uses three contrasting approaches to summarize commercial fishing data into three segment types:

  • Activity: a group of fishing trips with similar methods, target species, locations and or catch compositions
  • Fleet: a group of fishing vessel-years with similar attributes, and/or activities
  • Stock: a group of Fishstocks with similar taxonomy and/or habitat

Each type of segment provides a natural basis for looking at different types of data:

  • Activities are the most appropriate basis for summarising changes in fishing methods, target species, areas and catches;
  • Fleets are the most appropriate basis for summarising changes in vessel specifications such as length and age;
  • Stocks provide the most appropriate basis for looking at aspects such as changes in quota ownership and ACE holdings.

Fisheries of New Zealand uses a hierarchy within each type of segment. This provides for summaries at various levels of data aggregation and allows the user to drill down to the level of detail that is of interest.

Understanding the graphical summaries

Explanatory notes are provided for each graph, accessed by clicking on the graph title. These notes include important warnings that the user should be aware of when interpreting the summaries.


The data summarised in Fisheries of New Zealand are primarily statutory data collected by the Ministry for Primary Industries. Trident Systems has access to these data under a confidentiality agreement which restricts how these data may be reported. Fisheries of New Zealand seeks to adhere to these restrictions and, as a result, some catch and catch rate information is censored (blacked out) in the Fisheries of New Zealand data summaries. This occurs where an insufficient number of vessels and/or permit holders are represented in a particular calculation. Please provide feedback if you have concerns about data confidentiality and privacy in Fisheries of New Zealand.


If you would like to refer to summaries presented in Fisheries of New Zealand you can use the following citation:

Bentley, N.; Langley, A.D.; Middleton, D.A.J.; Lallemand, P. (2013) Fisheries of New Zealand, 1989/90-2011/12. Retrieved from http://fonz.tridentsystems.co.nz, day month year.

On-going development

Trident Systems is committed to the on-going updating and development of Fisheries of New Zealand. In addition to feedback on the detail, we welcome suggestions for particular developments to address specific fisheries management information needs.