Korean Journal of Fisheries and Aquatic Sciences (한국수산과학회지)

The Korean Society of Fisheries and Aquatic Science (한국수산과학회)
권호 표지
DOI QR코드

DOI QR Code

Stock Assessment of the Southern Bluefin Tuna Thunnus maccoyii Using the MULTIFAN-CL Model

MULTIFAN-CL 모델을 이용한 남방참다랑어 Thunnus maccoyii의 자원 평가

  • Kwon, You-Jung (Department of Marine Production Management, Pukyong National University) ;
  • Moon, Dae-Yeon (Distant Water Fisheries Resources Team, National Fisheries Research and Development Institute) ;
  • Zhang, Chang-Ik (Department of Marine Production Management, Pukyong National University) ;
  • Koh, Jeong-Rack (Fisheries Resources Restoration Development Management Center, National Fisheries Research and Development Institute)
  • 권유정 (부경대학교 해양생산관리학과) ;
  • 문대연 (국립수산과학원 해외자원팀) ;
  • 장창익 (부경대학교 해양생산관리학과) ;
  • 고정락 (국립수산과학원 자원회복사업단)
  • Published : 2007.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

We assessed the stock of the southern bluefin tuna (SBT, Thunnus maccoyii) by applying the MULTIFAN-CL model. The model is spatially disaggregated, with the population and fisheries stratified into a number of regions within the overall stock range. Catch, effort, length-frequency, and tagging data from 1965 to 2003 were stratified by three regions and four quarters (Jan-Mar, Apr-Jun, Jul-Sept and Oct-Dec). These data were used to estimate the instantaneous fishing mortality (F), biomass, spawning biomass, recruitment, and so on. The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) used only Japanese data and did not consider migration for the SBT stock assessment. By contrast, we used Japanese, Australian, New Zealand, Taiwanese, and Korean data, and considered migration. As a result, the estimated annual average F of all age classes was 0.073/yr and the F of age class 6-10 was the highest. The results also showed that the biomass and recruitment of SBT had declined significantly after 1965. Compared with the CCSBT results, the estimated spawning biomass in this study was lower and more uncertain. However, we will conduct a sensitivity analysis to get more accurate biological parameters and results. In addition, we need to use the bootstrap resampling method to quantify the uncertainty.

Keywords

References

  1. Butterworth, D.S., J.N. Ianelli and R. Hilborn. 2003. A statistical model for stock assessment of southern bluefm tuna with temporal changes in selectivity. Afr. J. Mar. Sci., 25, 331-361 https://doi.org/10.2989/18142320309504021
  2. CCSBT (Commission for the Conservation of Southern Bluefin Tuna). 2000. Report of the Special Meeting, Canberra, Australia
  3. CCSBT (Commission for the Conservation of Southern Bluefin Tuna). 2005a. Report of the Tenth Meeting of the Scientific Committee, Narita, Japan
  4. CCSBT (Commission for the Conservation of Southern Bluefin Tuna). 2005b. Report of the Sixth Meeting of the Stock Assessment Group, Taipei, Taiwan
  5. CCSBT (Commission for the Conservation of Southern Bluefin Tuna). 2006. Report of the Seventh Meeting of the Stock Assessment Group, Tokyo, Japan
  6. CCSBT (Commission for the Conservation of Southern Bluefin Tuna) web-site, http://www.ccsbt.org/docs/ data.html
  7. Fournier, D.A., J.R. Sibert, J. Majkowski and J. Hampton. 1990. MULTIFAN a likelihood-based for estimating growth parameters and age composition from multiple length frequency data sets illustrated using data for southern bluefin tuna (Thunnus maccoyii). Can. J. Fish. Aquat. Sci., 47, 301-317 https://doi.org/10.1139/f90-032
  8. Fournier, D.A., J. Hampton and J.R. Sibert. 1998. MULTIFAN-CL: a length-based age-structured population model for fisheries stock assessment, with application to South Pacific albacore (Thunnus alalunga). Can. J. Fish. Aquat. Sci., 55, 2105-2116 https://doi.org/10.1139/cjfas-55-9-2105
  9. IATTC (Inter-American Tropical Tuna Commission). 2005. Introduction of a statistical age-structured model used for southern bluefm tuna in CCSBT, CA, USA
  10. ICCAT (International Commission for the Conservation of Atlantic Tunas). 2006. Report for biennial period, 2004-05 Part II English version SCRS. 2, 120-127
  11. Hampton, J. and D.A. Fournier. 2001. A spatialy disaggregated, length-based, age-structured population model of yellowfin tuna (Thunnus albacares) in the western and central Pacific Ocean. Mar. Freshwater Res., 52, 937-963 https://doi.org/10.1071/MF01049
  12. Hampton, J. 2002. Stock assessment of skipjack tuna in the western and central Pacific Ocean. 15th Standing Committee on Tuna and Billfish Working Paper SKJ-1
  13. Polacheck, T., N.L. Klaer, C. Millar and A.L. Preece. 1999. An initial evaluation of management strategies for the southern bluefin tuna fishery. ICES J. Mar. Sci., 56, 811-826 https://doi.org/10.1006/jmsc.1999.0554