Sampling event Registered February 01, 2019

    Catch data from New Zealand research trawls since 2008

    Description

    This dataset contains data from research trawls that have occurred since 2008 and are stored the NIWA/MPI Trawl database These data results from data collected by research trawl surveys on research vessels and chartered commercial fishing vessels.Trawl surveys are a major tool used by research scientists for stock assessment. They are used to estimate basic parameters of commercial fish populations, including biomass, sex ratio, and the proportion of sexually mature fish, and the distribution of ages and lengths in the population. These parameters may be used in estimating mortality and growth rates.

    This dataset is a continuation of data from the NIWA/MPI Trawl database that was initially released as the New Zealand fish and squid distributions from research bottom trawls 1964-2008 available at https://nzobisipt.niwa.co.nz/resource?r=obisprovider

    Geographic scope

    Description

    New Zealand region

    Latitude
    From -57 to -24
    Longitude
    From -176.3 to 157

    Temporal scope

    single
    January 01, 2008

    Methodology

    Sampling

    Most records are from random bottom trawls, but there are also records from midwater trawls, scampi trawls and non-random tows (such as gear trials and target tows).

    Study extent

    Fisheries research trawls since 2008 over the New Zealand EEZ area

    Quality control

    The scientific names have been mapped to the World Register of Marine Species (WoRMS), using the online taxon match tool. All sampling locations have been plotted on a map to perform a visual check. The most important check would be to see if all sampling locations are (1) in the marine and/or brackish environment and (2) within the described sampling area.

    Method steps
    1. Only successful trawl records were selected. All "foul" shots are excluded as the net may have ripped and some species may have escaped on hauling. All species identification have been validated and outliers based on geographic and depth distributions have been checked.

    2. Catch weights (kg) are added to the "occurrenceRemarks" field. -Sea temperature recorded by trawl headline sensors are added to the "dynamicProperties" field.

    Additional info

    marine, harvested by iOBIS

    Contacts

    • Kevin Mackay

      Originator
      Metadata author
      Organization
      NIWA
      Position
      Marine Database Manager
      Address
      Private Bag 14-901
      Roles
      Originator
      Metadata author
    • Kevin Mackay

      User
    • David Fisher

      Administrative point of contact
      Organization
      NIWA
      Position
      Principal Technician - Fisheries
      Address
      Private Bag 14-901
      Roles
      Administrative point of contact

    GBIF registration

    Registration date
    February 01, 2019
    Metadata last modified
    November 27, 2019
    Publication date
    November 27, 2019
    Hosted by
    The National Institute of Water and Atmospheric Research (NIWA)
    Installation
    Southwest Pacific Regional OBIS Node
    Endpoints
    Darwin Core Archive
    EML
    Preferred identifier
    10.15468/gzpcyl
    Alternative identifiers

    Citation

    SWPRON (2017). Catch data from New Zealand research trawls. Southwestern Pacific OBIS, National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand, 15157 records, Online http://nzobisipt.niwa.co.nz/resource.do?r=trawl released on April 19, 2017. https://doi.org/10.15468/gzpcyl accessed via GBIF.org on 2025-08-15.