Protected species bycatch in New Zealand fisheries

Edward Abraham, Dragonfly Data Science

Dataset credit



Primary contact Edward Abraham Dragonfly Data Science N/A
Secondary contact E. R. Abraham Dragonfly Data Science N/A
Secondary contact F. N. Thompson Dragonfly Data Science N/A


Abraham E R, Thompson F N (2016): Protected species bycatch in New Zealand fisheries. v1.6. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. Dataset/Occurrence.
Abraham, E. 2020. Protected species bycatch in New Zealand fisheries. Data downloaded from OBIS-SEAMAP ( on yyyy-mm-dd and originated from OBIS (


Seabirds, marine mammals, and turtles are caught during commercial fishing operations within the New Zealand Exclusive Economic Zone. In order to monitor the impacts of fishing on these species, New Zealand government observers on fishing vessels record any protected species bycatch incidents that occur. Observer data on protected species captures are maintained by the Ministry for Primary Industries, with identification of captured animals carried out by the Department of Conservation. The data have been summarised in a series of reports, with the most recent report covering the period from 2002–03 to the end of the 2008–09 fishing year (Abraham and Thompson 2011b).
This dataset provides a summary of protected species bycatch in trawl and longline fisheries, from the 2002–03 to 2012–13 fishing year (fishing years run from October 1 to September 30).
Observers are only present on some fishing vessels. To estimate total captures in a fishery, it is necessary to use statistical methods to extrapolate from the observed fishing to the unobserved fishing. The total observable captures are an estimate of the captures that would have been reported, had observers been present on all fishing vessels. There may be additional mortalities (such as birds that are struck by fishing gear but not brought on board the vessel) that are not recorded by observers. These are referred to as ‘cryptic mortalities’ and are not included in the estimates of total captures, nor is there any evaluation of potential survival of seabirds recorded as captured but subsequently released alive. The methods used for the estimation follow those described in technical reports on bycatch estimation for seabirds (Abraham and Thompson 2011a, Abraham et al. 2013), and marine mammals (Thompson et al. 2013).
####Notes about some Fields:

- **fishing_year** the fishing year of the capture. Fishing years run from 1 October to 30 September;

- **datetime** the date and time of the capture. All times are in New Zealand Standard Time (GMT+12);

- **status** whether the animal was alive or dead;

- **identification** how the identification was made (necropsy: by necropsy of the dead animal; photograph: from
an expert inspection of a photograph of the capture; imputation: imputed by correcting the observer code using
necropsy and photographic identifications of other captures with the same observer identification; as reported
by the observer);
- **method** the fishing method (surface longline; bottom longline; trawl; set net; or purse seine);

- **target** the target species reported by the fisher;

- **vessel_size** the length class of the vessel (a range in m).



Supplemental information

This dataset was downloaded from OBIS ( The records for only marine mammals, seabirds, sea turtles and rays and sharks were extracted. Records with no longitude/latitude or no date (eventDate) were excluded.
OBIS dataset page:
Data Provider's dataset page:


Abraham E R, Thompson F N (2016): Protected species bycatch in New Zealand fisheries. v1.6. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. Dataset/Occurrence.



This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes described below represent those in the original dataset provided by the provider.
All attributes are included in the downloadable file (CSV or ESRI File Geodatabase) for "Complete Set of Dataset".

Attributes in dataset

Attribute (table column)Description
oidInternal ID
idRecord ID
dataset_idDataset ID
scientificnameScientific name
vernacularnameVernacular name
aphiaidAphia ID
taxonranktaxononic rank
individualcountGroup size / individual count
eventdateEvent date (precision varies)
eventtimeEvent time
decimallatitudeLatitude in decimal degrees
decimallongitudeLongitude in decimal degrees
coordinateprecisionCoordinate precision
catalognumberCatalog number
collectioncodeCollection code
occurrencestatusOccurrence status
basisofrecordBasis of record (HumanObservation / MachineObservation)
modifiedDate/time the record was modified
node_idNode ID
occurrenceidOccurrence ID
occurrenceremarksOccurrence remarks
eventidEvent ID
institutioncodeInstitution code
lifestageLife stage
sexGender of the animal if known
speciesSpecies by provider
datasetidDataset ID by provider
localityLocation of ocean
waterbodyDetails of ocean
droppedFlag indicating the record was dropped (always false)
absenceFlag indicating the record represents the absence of the species (always false)
marineFlag indicating the record is for marine life (always true)
Marine mammals115
Sea turtles15
Rays and sharks21
Other species0
Non spatial0
Non species0
Date, Begin2013-10-04
Date, End2018-09-26
Temporal prec.111000
Latitude-53.72 - -33.59
Longitude-179.98 - 179.96
Coord. prec.6 decimal digits
Data typeAnimal sighting
Traveled (km)0
Contr. throughiOBIS
Sharing policy CC-BY (All)
Shared with None
See metadata in static HTML
See metadata in FGDC XML
See download history / statistics