Data for the analysis protected species captures

These data were prepared for the analysis of protected species captures. Fishing effort, observer data, and protected species capture data have been groomed for this purpose, and the reported captures and fishing effort may differ from the values reported elsewhere.

Licence

Data are made available for reuse by the Ministry for Primary Industries, under a creative commons 3.0 New Zealand attribution licence, following the recommendations of NZGOAL. This licence allows the data to be used for any other purpose and republished, provided that attribution is given to the source.

Data files

protected_species_captures.csv

A comma-delimited text file containing a row for each capture of a seabird, marine mammal, turtle, reported by Government fisheries observers, where the capture was the result of fishing activity. The data are restricted to fishing that occurred within the New Zealand Exclusive Economic Zone, and to fishing by trawl, longline, set net and purse seine methods. Captures include animals that were killed, as well as those that were released alive. The data in this file cover the period 2002–03 to 2020–21.

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.

• taxon the best idenification of the capture. The names given are common names.

• 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).

• capture_method how the animal was caught. In many cases, the capture method was not recorded by the observer (net: caught in a net; hook: caught by a hook; line: caught during surface longline fishing;
  warp or door: caught on a trawl warp or on the door; unknown: capture method reported by the observer as unknown; other: capture method reported by the observer as 'other'; tangled: tangled by the line during longline fishing; mitigation device: caught by a seabird mitigation device; paravane: caught on the paravane or by the paravane wire; net restrictor: caught on the net restrictor that is used during some scampi fishing)

• 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)

• area the area of the fishing

• version a version number that identifies this data set

• latitude the latitude of the capture (decimal degrees). The positions are accurate to within 0.05 degrees (around 6 km). The latitude of the captures was first rounded to the nearest 0.05 degrees, and a random jitter of plus or minus 0.025 degrees was then added. This ensures that the captures data meets Ministry for Primary Industries anonymisation requirements (the positions do not precisely refelect the location of fishing events).

• longitude the longitude of the capture (decimal degrees). The longitude has been jittered in the same way as the latitude.

species_fishery_year_summary.csv

Comma-delimited text summarising the number of observed captures in each fishing year and fishery.

Fields

• year the fishing year

• method the method of the fishing

• fishery the target fishery of the fishing. The fisheries are albacore longline, bigeye longline, bluenose longline, deepwater trawl, flatfish set net, flatfish trawl, grey mullet set net, hake trawl, hapuka longline, hoki trawl, inshore trawl, jack mackerel trawl, ling longline, ling trawl, mackerel purse seine, middle depth trawl, minor bottom longline,minor purse seine, minor set net, minor surface longline, scampi trawl, shark set net, skipjack purse seine, snapper longline, southern bluefin longline, southern blue whiting trawl, squid trawl, swordfish longline.

• tows the number of tows (for trawl fishing)

• hooks the number of hooks (for longline fishing)
• net_length the length of the net (m) (for set net fishing)
• sets the number of sets for purse seine fishing
• percent_observed the percentage of fishing that was observed

For the following species and species groups the table lists the number of captures in the corresponding year and fishery:

• white_capped_albatross New Zealand white-capped albatross
• salvins_albatross Salvin's albatross
• southern_bullers_albatross Southern Buller's albatross
• other_albatrosses All other albatross species
• white_chinned_petrel White-chinned petrel
• sooty_shearwater Sooty shearwater
• other_birds All other birds
• new_zealand_sea_lion New Zealand sea lion
• new_zealand_fur_seal New Zealand fur seal
• other_seals All other pinnipeds (e.g., leopard seal, elephant seal, unidentified seals)
• common_dolphin Common dolphin
• other_dolphins Other delphinids
• pilot_whale Pilot whale
• whales All other cetaceans
• hectors_dolphin Hector's dolphin
• turtles All turtles

effort_position_summary.csv

Comma-delimited file summarising fishing effort for trawl, longline, set net, and purse seine fishing within 0.2 degree cells. These are the data that were used to generate the maps seen on the PSC website. The data are grouped by fishing method and target species, and are the annual average fishing effort over the three most recent fishing years to 2020–21 (1 October 2018 to 30 September 2021). Not all fishing effort data was reported by fishers with a location, and some fishing effort was given an imputed position (based on randomly sampling fishing by similar vessels in the same fishery and area). There is a column that records the percentage of effort which was given an imputed position. Fishing effort that did not meet Ministry for Primary Industries data anonymisation requirements (three or more vessels or entities within each group), was grouped without a position. Fish species that were targeted by fewer than three vessels or clients over the period were grouped as "other species".

Fields

• method the method of the fishing
• target the fisher-declared target fish species or species groups (common names as used by MPI)
• location_status for missing locations: "unknown", if no location data were available and location could not be imputed, or "censored" if fewer than three vessels or entities were fishing within the 0.2 degree cell over the three years
• latitude latitude of the center of the 0.2 degree cell
• longitude longitude of the center of the 0.2 degree cell
• tows the average number of tows per year (for trawl fishing)
• hooks the average number of hooks per year (for longline fishing).
• net_length the mean length of the net (m) per year (for set net fishing)
• sets the average number of sets per year for purse seine fishing
• percent_imputed the percentage of fishing with imputed locations
• percent_observed the percentage of fishing that was observed