Report of the Working Group on Methods of Fish Stock Assessments (WGMG)

The Working Group on Methods on Fish Stock Assessments [WGMG] (Chair: C.M. O’Brien, UK) will meet in Lisbon, Portugal, from 11–18 February 2004 to: a) develop robust methods and software for the investigation of management procedures for stock recovery and the evaluation of harvest control rules; b) identify appropriate estimators of stock conservation limits and reference points relating to longer-term potential yield; together with a characterisation of their statistical properties for the range of stocks currently assessed by ICES for its client  customers and related management agencies (EU, IBSFC, NAFO, NASCO, NEAFC, ICCAT); c) examine software capable of generating simulated data, and agree on an initial suite of data sets for use in model-testing and evaluation that will be made generally available from the ICES website; d) investigate appropriate diagnostics that detect model mis-specification in fish stock assessment;

e) investigate and implement statistical approaches that identify and quantify uncertainty due to conditioning choices in fish stock assessment; f) develop fishery-independent assessment methods, measures of uncertainty, and appropriate diagnostics, with particular attention to data-poor situations and the estimation of relative catchability; and g) review, revise and adopt guidelines on the formal procedures to be adopted by the Working Group for the testing, evaluation and validation of software for use by ICES stock assessment Working Groups.