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Stock and Fishery Dynamics of Yellowfin Tuna, Thunnus albacares, in the Western and Central Pacific Ocean: Development of an Integrated Model Incorporating Size and Spatial StructureProject Overview
This project will apply the SPARCLE model developed for south Pacific albacore to the analysis of yellowfin tuna and extend the model to include spatial variability. The SPARCLE model analyses length frequency, catch and effort data in an extremely flexible way and can accommodate multiple gear types, non-uniform sampling over time, and samples with part of the data missing. It is capable of estimating trends in population biomass independently of changes in gear technology. The new research will extend this approach to explicitly include spatial variability in population density and age (and size) structure. The geographic area to be included will encompass the entire range of the western Pacific yellowfin fishery including WPRFMC jurisdictions.
Dr. John Hampton
Secretariat of the Pacific Community (SPC)
Noumea Cedex, New Caledonia
Dr. David Fournier
P.O. Box 2040
Canada V8L 3S3
PDF file of Hampton and Fournier reprint, "A spatially-disaggregated, length-based, age-structured population model of yellowfin tuna (Thunnus albacares) in the western and central Pacific Ocean", John Hampton and David Fournier, Marine Freshwater Resources, 52: 937-963, 2001
Updated MULTIFAN-CL based assessment of yellowfin tuna, a Working Paper presented at SCTB 13, July 5-12 2000, Noumea. (PDF file from SPC-OFP web site, 1.1 MB)
Progress Report - June 1997Background
In late 1993, a small group of scientists from the Western Pacific Yellowfin Research Group (WPYRG) examined the prospects for developing an integrated model of yellowfin dynamics, incorporating both size and spatial structure. A modelling strategy, building on the length-based assessment model (MULTIFAN CL) applied to South Pacific albacore, was developed. The key extension of MULTIFAN CL envisaged was that spatial structure, initially in the form of the 7 WPYRG areas, would be incorporated into the model. Inputs to the proposed model would include total catch and effort data, length frequency samples and tagging data, all variously stratified by gear, fleet, area and time period. The University of Hawaii PFRP has provided funding for two-year project to coordinated by the Oceanic Fisheries Programme of the South Pacific Commission.
Work has continued on the development of MULTIFAN CL, mainly through application to the albacore data from the SPC's Albacore Research Project. Key model developments incorporated in the past year include:
1997-98 Work plan
Due to technical difficulties associated with model development, particularly the incorporation of tagging data into the analysis, and a delay in the provision of year 2 funding to the 1997-98 FY, we have fallen somewhat behind schedule in the application of the model to yellowfin data. However, we expect to finalize the application of MULTIFAN CL to yellowfin in 1997-98, subject to receipt of project funding. We will focus on the following activities:
(a) Continue to enhance the model, in particular to:
(b) Obtain at least a preliminary "best fit" to the yellowfin data, which can then be used to investigate relevant management questions.
(c) Fully document the model and its application to western and central Pacific yellowfin.
This page updated August 16, 2006