OBJECTIVES: The main objective of this training workshop is to introduce NFRDI scientists involved in fish stock assessment to three new methods, viz.: (i) for the assessment of fish stocks using time series of catch data and estimates of resilience which can be derived from FishBase, here referred to as CMSY; (ii) for estimating a snapshot of stock status from length-frequency data from commercial catches, here referred to as LBB; (iii) for estimating stock status purely from a time series of catch per unit of effort data, here referred to as AMSY.
MODULE DESCRIPTIONS
CMSY: This module is based on the method for estimating MSY from catch and resilience of Martell and Froese (2013)[1], which was elaborated by Froese et al. (2016)[2], and applied to 397 stocks in 14 European ecoregions by Froese et al. (2016; see also https://github.com/SISTA16/cmsy)[3]. The biological data used to estimate resilience will be supplied by FishBase (www.fishbase.org)[4], created by Rainer Froese and Daniel Pauly in the 1990s, and which is the information system of choice on fish by more than half a million users worldwide. The estimation of priors for this CMSY method was recently integrated as a table in FishBase and has data for most exploited species.
Data required:
- Stock is defined according to ecosystem, and not according to fishing zone;
- A minimum of 10 continuous years of catch data expressed in weight units;
- Resilience (quantitative or qualitative) gathered from FishBase/SeaLifeBase;
- If available, abundance indicators expressed as time series (minimum of three years) of catch-per-unit-of-effort (CPUE) or standing stock biomass;
- If available, independent estimates of B/BMSY for specific years (the most recent of the time series is preferred), and which can be estimated using the LBB method (see below);
- Format data sets according to the Stock_Catch.CSV and Stock_ID.CSV templates provided in the workshop Dropbox folder for the CMSY package.
LBB: This module is based on the method described in Froese et al. (2018; see also https://www.fishbase.de/rfroese/LBB_UserGuide_1.zip)[5] for estimating B/BMSY based on an assumption that fish grow according to the von Bertalanffy growth equation (VBGF) with parameters, viz.: asymptotic length (Loo), length at first capture (Lc), relative natural mortality (M/K) and relative fishing mortality (F/K) obtained from length-frequency data representative of the commercial catch. Estimates of Loo from FishBase can be used to inform this model.
Data required:
- Length-frequency data must be representative of the annual commercial catch, i.e., can be a sample from the catch but raised to the total catch;
- Viable estimates of VBGF parameters, i.e., representative of the population sampled;
- Format data sets according to the ComDat.CSV and Stock_ID.CSV templates provided in the workshop Dropbox folder for the LBB package.
AMSY: This module is still in its preliminary stage, but has shown promising results. It uses a time series of CPUE data with qualitative knowledge of the current stock size (or stock status) and resilience to estimate B/BMSY. The user guide is still being developed but will be ready for the workshop.
Data required:
- CPUE time series, minimum of 10 continuous years;
- Qualitative knowledge of current stock size;
- Qualitative knowledge of resilience of the stock;
- Format data according to *.CSV templates provided in the workshop Dropbox folder for the AMSY package.
RESOURCE PERSONS: Dr. Rainer Froese (GEOMAR, Helmholtz-Centre for Ocean Research, Germany), Dr. Maria Lourdes D. Palomares (Sea Around Us, University of British Columbia, Canada), Ms. Patricia Sorongan Yap (FishBase, Los Baños, Laguna, Philippines), Ms. Jeniffer Espedido (FishBase, Los Baños, Laguna, Philippines) and Ms. Vina Angelica Parducho (FishBase, Los Baños, Laguna, Philippines).
WORKSHOP REPORT
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[1] Martell, S. and Froese, R. (2013) A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14(4): 504-514. (download article from http://www.fishbase.de/rfroese/Martell_Froese_2012_SimpleMethod.pdf)
[2] Froese, R., Demirel, N., Coro, G., Kleisner, K.M., and Winker, H. (2016) Estimating fisheries reference points from catch and resilience. Fish and Fisheries 18(3): 506-526. (http://oceanrep.geomar.de/33076/; see also http://www.fishbase.de/rfroese/Appendix_4.pdf).
[3] Froese, R., Garilao, C., Winker, H., Coro, G., Demirel, N., Tsikliras, A., Dimarchopoulou, D., Scarcella, G. and Sampang-Reyes, A. (2016) Exploitation and status of European stocks. World Wide Web electronic publication (http://oceanrep.geomar.de/34476/).
[4] SeaLifeBase (www.sealifebase.org) will be used for invertebrate stocks.
[5] Froese, R., Winker, H., Coro, G., Demirel, N., Tsikliras, A.C., Dimarchopoulou, D., Scarcella, G., Probst, W.N., Dureuil, M. and Pauly, D. (2018) A new approach for estimating stock status from length frequency data. ICES Journal of Marine Science 75(6): 2004-2015. (download article from https://www.fishbase.de/rfroese/LBBcor_fsy078.pdf).