Protected species bycatch in New Zealand fisheries

E. R. Abraham1, F. N. Thompson2, Edward Abraham1

1 Dragonfly Data Science, PO Box 27535, 6141, Wellington, New Zealand; 2 Dragonfly Data Science, PO Box 27535, 6141, Wellington, New Zealand

Corresponding author(s): E. R. AbrahamF. N. Thompson

Received {date}; Revised {date}; Accepted {date}; Published {date}

Citation: Combination of authors, year of data paper publication (in parentheses), Title, Journal Name, Volume, Issue number (in parentheses), and doi of the data paper.

Resource Citation

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. https://nzobisipt.niwa.co.nz/resource?r=protected_species_bycatch_nz&v=1.6

Abstract

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 2019–20 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).

Keywords: Occurrence, Occurrence

General description

Additional information: marine, harvested by iOBIS

Data published through GBIF: https://nzobisipt.niwa.co.nz/resource?r=protected_species_bycatch_nz

Spatial coverage

General spatial coverage: New Zealand Exclusive Economic Zone
Coordinates: 57°0'0''S and 24°0'0''S Latitude; 157°0'0''E and 165°0'0''W Longitude 

Temporal coverage: October 1, 2002 - September 30, 2020

Datasets

Dataset description
Object name: Darwin Core Archive Protected species bycatch in New Zealand fisheries
Character encoding: UTF-8
Format name: Darwin Core Archive format
Format version: 1.0
Distribution: https://nzobisipt.niwa.co.nz/archive.do?r=protected_species_bycatch_nz
Publication date of data: 2022-08-29
Language: English
Licences of use: Creative Commons Attribution (CC-BY) 4.0 License

Metadata language: English
Date of metadata creation: 2016-05-27
Hierarchy level: Dataset

References
Abraham E. R., Thompson F. N. (2014). Captures of turtles in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/turtles/trawl/all-vessels/eez/all/
Abraham E. R., Thompson F. N. (2014). Captures of all birds in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/birds/trawl/all-vessels/eez/all/
Abraham E. R., Thompson F. N. (2014). Captures of whales and dolphins in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/whales-and-dolphins/trawl/all-vessels/eez/all/
Abraham E. R., Thompson F. N. (2014). Captures of New Zealand sea lion in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/new-zealand-sea-lion/trawl/all-vessels/eez/all/
Abraham E. R., Thompson F. N. (2014). Captures of New Zealand fur seal in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/new-zealand-fur-seal/trawl/all-vessels/eez/all/
Abraham E. R., Thompson F. N. (2014). Captures of other seals in trawl fisheries, in the New Zealand Exclusive Economic Zone, from 2002–03 to 2012–18. https://data.dragonfly.co.nz/psc/v20140201/other-seals/trawl/all-vessels/eez/all/