 about
the WPTT |
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 objective |
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To
review and analyse issues relevant to the fisheries
and status of yellowfin tuna ( Thunnus albacares ),
skipjack tuna ( Katsuwonus pelamis )
and bigeye tuna ( Thunnus obesus ). For a complete list of the terms
of reference for this and other species working group click here. |
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chairman
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Dr.
Hilario Murua |
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| available datasets |
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The following datasets will be available for download. Please let us know if you encounter any problems in accessing the data. These datasets have been submitted to several validation procedures at the Secretariat. However, the procedures might not be exhaustive enough to uncover all potential problems. If you discover any major inconsistency in the data, please let us know as soon as possible. Click here to download a Microsoft word version of the text below.
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Data Catalogues (in prep): |
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The file CAT_TROP11.pdf (21-09-2011), contains information on the amount of nominal catches strata for which catch and effort and/or size frequency data are available for tropical tuna species, by species.
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Nominal Catches (available): |
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Total catch estimates per Fleet, Year, Gear, IOTC Area and species. The catches not reported per species or gear were assigned to the corresponding gears and/or species by the Secretariat.
The catches estimated for 1950-2010 and details about the data source and data quality can be found in the spreadsheet:
NC_TROP.xls (as of 22-8-2011) (compressed with WinZip)
Please, note that the catches for 2010 represent preliminary figures.
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Catches and Effort (available): |
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Catch and effort data (as of 1-9-2011) are presented as three different files (compressed with WinZip):
• vessels using drifting longlines — CELL.csv
• vessels using pole and lines or purse seines — CEPSBB.csv
• vessels using gears other than those referred to above — CEOTHR.csv
Or click here if you want to download the above three files in one go CEALL.zip
Catches (in tonnes or/and in number) and effort are recorded per Fleet, Year, Gear, Type of School, Time Interval (month or quarter usually), grid (usually 1 degree square areas for surface gears and 5 degrees square areas for longlines) and species.
Catches and effort are not available for all Nominal catches strata. When recorded, the catches in these datasets might represent the total catches of the species in the year for the fleet and gear concerned or represent simply a sample of those.
More details about the catch and effort information available and the way in which the above text files might be read can be found in CE_Reference.xls
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Raised catches per area for tropical tunas, albacore and swordfish (in prep): |
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The Secretariat estimated catches of bigeye tuna, yellowfin tuna, skipjack tuna, albacore and swordfish per gear, (School type), year, and 5 degrees square grid from the available nominal catches. These can be found in C_BIG5_raised.csv (in prep.)(compressed with WinZip)
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Size frequency data (available): |
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The available data on the sizes of tropical tunas caught by the different fisheries are presented as:
Available size frequency data: The size frequency data available in the IOTC databases is presented in FL_YFT.csv (9-9-2011) , FL_BET.csv (9-9-2011) and FL_SKJ.csv (9-9-2011). All size data strata not recorded as fork length was converted into fork length by using the equations in Equations.doc. Fish recorded under size classes other than those used for tropical tuna species was assigned to the corresponding size class/es for each species (first class is 10cm for all tropical tunas and class interval is 2cm for yellowfin tuna and bigeye tuna and 1cm for the skipjack tuna).
Raised size frequency data or Catch-at-Size data: The available size data for bigeye tuna, yellowfin tuna and skipjack tuna was raised to the total catches recorded for the species, when required. The results of this process are presented as:
The estimated size frequency data are presented in CAS_TablesBET.xls (12-9-2011), CAS_TablesSKJ.xls (13-9-2011), CAS_TablesYFT.xls (9-9-2011). These spreadsheets contain also information on the amount of data substitution required, average weights estimated from the estimated data and other information.
Details about the amount of data available to create the above files can be found in SF_reference.xls.
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Skipjack tuna data for SS3 (available):
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The Secretariat prepared a file, SKJ_SS3 - L3cm.xls (20-6-2011) (compressed with WinZip), for the stock assessment of skipjack tuna including total catch and available length frequency data by fishery, year, and quarter. More details about the contents of this file and a summary of the information presented are also provided (worksheets ReadMe and SKJ_SS3_SUMMARY of the Excel file).
The excel file SKJ_CPUE_MDV_BB.xls (to be released) contains CPUE indices, as estimated for the pole-and-line fishery operated in the Maldives (Dale KOLODY).
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Yellowfin tuna data for MF-CL and SS3 (available): |
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The Secretariat has prepared two datasets for the stock assessment of yellowfin tuna, including total catch and available effort and length frequency data by fishery, assessment area, year and quarter:
- File MFCL_YFT.xls (9-9-2011) (compressed with WinZip), including catches for the following fisheries: Industrial purse seine on free-schools, industrial purse seine on associated schools, industrial longline, pole-and-Line, Trolling, Handline, and other artisanal fisheries . More details about the contents of this file are provided in a separate file (MFCL_YFT_readme), which is located within the same compressed folder.
- File MFCL_YFT_v2.xls (21-9-2011) (compressed with WinZip), including catches for the above fisheries plus separate catches and effort for fresh-tuna longline fisheries (combined with longline fisheries in the file above). More details about the contents of this file are provided in a separate file (MFCL_YFT_readme_v2), which is located within the same compressed folder.
The excel files below contain CPUE indices by area, as estimated for the deep-freezing longline fleets of Japan (Hiroaki OKAMOTO) and Taiwan,China (Yu-Min YEH):
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Bigeye tuna data for ASPM (available): |
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The Secretariat has also prepared a file, ASPM_BET.xls (9-9-2011) for the stock assessment of bigeye tuna including number of specimens of bigeye tuna by age class, fishery, year and quarter, as derived from:
- Catch-at-size (CAS) data estimated from the available size frequency data for bigeye tuna, for 1950-2010 (as in CAS_TablesBET.xls, Worksheet FI-YY-QQ).
- The following VB log k model (Laslett, Eveson and Polacheck method, IOTC-2008-WPTT-09) using the following parameter estimates:
An Age-Length key was derived from above and used to convert the numbers of specimens estimated by length (CAS) into age (CAA).
The excel files below contain CPUE indices by area, as estimated for the deep-freezing longline fleets of Japan (Hiroaki OKAMOTO) and Taiwan,China (Yu-Min YEH):
The excel file below contains Standardized CPUE for bigeye of the Korean tuna longline fisheries in the Indian Ocean (1977-2009):
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For further information: |
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Please, do not hesitate to contacting the IOTC Secretariat (secretariat@iotc.org or data.assistant@iotc.org) if you have any question regarding these datasets.
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to date |
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Click
here to consult the list
of the previous Sessions of the WPTT, with links to download
the Reports and the presented documents. |
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Most documents are in Adobe's Portable Document Format (PDF 5) : get the free Acrobat Reader here.