Protected species bycatch in New Zealand fisheries

OBIS and SWP 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).

N/A

This dataset was downloaded from OBIS (https://obis.org/). 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:
https://obis.org/dataset/90d8bc63-5336-443f-b47d-a3f0c8e99d73
Data Provider's dataset page:
https://nzobisipt.niwa.co.nz/resource?r=protected_species_bycatch_nz

Overview

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
oid	Internal ID
id	Record ID
dataset_id	Dataset ID
scientificname	Scientific name
vernacularname	Vernacular name
aphiaid	Aphia ID
taxonrank	taxononic rank
individualcount	Group size / individual count
eventdate	Event date (precision varies)
eventtime	Event time
decimallatitude	Latitude in decimal degrees
decimallongitude	Longitude in decimal degrees
coordinateprecision	Coordinate precision
catalognumber	Catalog number
collectioncode	Collection code
occurrencestatus	Occurrence status
basisofrecord	Basis of record (HumanObservation / MachineObservation)
modified	Date/time the record was modified
node_id	Node ID
occurrenceid	Occurrence ID
occurrenceremarks	Occurrence remarks
eventid	Event ID
institutioncode	Institution code
lifestage	Life stage
sex	Gender of the animal if known
species	Species by provider
datasetid	Dataset ID by provider
country	Country
locality	Location of ocean
waterbody	Details of ocean
dropped	Flag indicating the record was dropped (always false)
absence	Flag indicating the record represents the absence of the species (always false)
marine	Flag indicating the record is for marine life (always true)