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
The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 13,583 records.
2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
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.
Researchers should respect the following rights statement:
The publisher and rights holder of this work is Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.
This resource has been registered with GBIF, and assigned the following GBIF UUID: 421890f7-e909-40ed-a573-b1c9529a55fa. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.
- Metadata Provider ●
- Originator ●
- Point Of Contact
New Zealand region
|Bounding Coordinates||South West [-57, -176.3], North East [-24, 157]|
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 step description:
- 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.
- Catch weights (kg) are added to the "occurrenceRemarks" field. -Sea temperature recorded by trawl headline sensors are added to the "dynamicProperties" field.
marine, harvested by iOBIS