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Statistics Working Group

General Information

The Statistics Working Group (STATWG) was established in 2006. The ISC has no standing Secretariat, so the STATWG oversees the tasks of data collection, compilation archival and dissemination. The STATWG is also responsible for the development and maintenance of the ISC centralized database and ISC website.

Data Reporting

ISC Members are required to annually report the following data:

  • Category I: total annual catch (round weight by species) and total annual effort (number of active vessels) by fishery
  • Category II: catch-effort aggregated by spatial and temporal strata (summary of logbook data)
  • Category III: biological data (size composition, length or weight frequencies, sex information)

See more information about Data Reporting.

Data Reporting and Exchange

The minimum data required for ISC fishery monitoring and resource assessment fall into three categories:

  • Category I: total annual catch (round weight by species) total annual effort (active vessels by fishery)
  • Category II: catch-effort (summary of logbook data)
  • Category III: biological data, (size composition, length or weight frequencies, sex information).
CATEGORY I (Total annual catch and total annual effort):

Total annual catch in metric tons (round weight) should be reported by gear, species and country for fisheries in the North Pacific (north of the equator). When established, data should be reported by subarea (see Section 2). If round weight is estimated from processed weight, the conversion procedure is to be noted.Total nominal effort in numbers of active vessels fishing should be reported by fishery, gear and size category for fisheries in the North Pacific. As with catch, reporting should be done by subarea of the North Pacific. However, if effort cannot be reported by subarea or even for the North Pacific, effort should be reported for a larger area and noted. Vessel size categories to be used in reporting effort are:

Vessels Size Category
Longline 1. Distant-water and 2. offshore (Chinese-Taipei)
1. Distant-water, 2. offshore, and 3. coastal (Japan)
Purse seine 1. large (>260 cubic meter capacity; ~300 mt)
2. small (<260 cubic meter capacity; ~300 mt)
1. distant-water and 2. offshore (Japan)
Harpo Troll, gill net, etc. aggregated by type
CATEGORY II (Catch-effort):

Catch and effort (logbook) data should be reported by country, gear type, and month. The resolution is as follows:

Gear Effort Region
Longline 5x5 deg. no. or wt.hooks
(all species recorded)
entire Pacific
Purse seine 1x1 deg.* no. fishing days
(include searching)
entire Pacific
Troll 1x1 deg. no. fishing days
(include searching)
North Pacific
Gill net 1x1 deg. no. tans or net-days North Pacific
Harpoon 1x1 deg. no. fishing days North Pacific
Handline 1x1 deg. no. lines North Pacific
Pole and line 1x1 deg. no. poles/successful days North Pacific
Other 1x1 deg. no. or wt. as needed North Pacific

*5x5 degree data if 1x1 notpracticable

CATEGORY III (Biological data):

Size composition (length or weight frequencies) and sex data (for swordfish, striped and blue marlins) should be reported by gear type and with the same area resolution as required for Category II data. However, coarser area resolution may be substituted if this requirement can not be applied. Reporting of length-frequencies should be with intervals of 1 or 2 cm. After standard measurements are established (see Section 2, above), both standard measurement and the actual sampling measurement unit should be reported.All size composition data should include notes on collection method, e.g. port sampled, observer sampled, fisherman sampled, etc. Accuracy of measurement should also be reported (e.g. to the nearest cm, next larger cm, nearest kg, etc.).

Data Access and Availability

The participants agreed that some extracts from ISC database, that do not contain proprietary information, should be made available to the general public. Category I data aggregated over the entire North Pacific will be considered public domain (PD) data. The PD data will include the caveat that some discards are not reported in the catch statistics provided. Data provided for use and held by the ISC in whatever form remains the property of the individual contributors 1. Release of these data to the general public may be governed by policies of the contributor.

However, raw Category I data as well as Category II and Category III data contain proprietary information and, therefore, shall be made available to contributors only and to scientists of ISC working groups. Japan will be responsible for managing the central data depository and will designate a control person. When a request for non-PD data is received from a member of the general public, the data manager will notify and seek approval and conditions from the contributors of the specific data requested prior to release. A record of all requests received from the general public and the disposition of the request will be maintained and reported at each meeting of the ISC Plenary.

Requests for non-PD data by contributors for purposes other than ISC stock assessment activities will be handled by the control person, following the same procedures delineated in the previous paragraph.

While there is consensus among all contributors regarding the data access rules, outlined above, there is concern that these rules may be changed at some point in the future without the consent of all contributors. It was recommended that the rules not be changed without consensus of all contributors.

1 As used here and throughout this report, Contributors are all ISC participants who have provided data to ISC for inclusion in its database.

Data Reporting Schedule

Each year, data correspondents will submit CategoryI , Category II and Category III data to ISC on or before July 1st.CategoryI data are to be submitted to both the Data Administrator and Working Group Data Managers. Category II and Category III data are to be submitted to the respective Data Managers of the species Working Groups,e.g. logbook data, (Category II) for albacore fisheries are to be submitted to the ALBWG Data Manager. These annual data submissions will have two components:

  1. preliminary esrimates of a;; available statistics from the previous year
    (CategoryI , Category II and Category III data);and
  2. all available updates of CategoryI , Category II and Category III data from all earlier years.

Category II longline fishries contain catches of many different species and each species is of interest to a different species Working Group. Standardization and validarion of the data, especially fishing effort, should be performed once rather than by each species Working Group independently. The STATWG will coordinate this task with involvement of experts from the species Working Groups.

Adopted ISC4, February 4, 2004


  1. Data collection
  2. Maintenance of ISC Database and Website
  3. Statistical information exchange with other organizations
  4. Coordination of sampling programs conducted by Members

Working Group Reports and Working Papers

Working Group Chair
Ren-Fen Wu
Working Group Co-Chair
Darryl Tagami