Management strategy evaluation for Greenland halibut (Reinhardtius hippoglossoides) in NAFO Subarea 2 and Divisions 3LKMNO

• Main Authors: Miller, David C M, Shelton, Peter A, Healey, Brian P, Brodie, William B, Morgan, Joanne M, Butterworth, Doug S, Alpoim, Ricardo, González, Diana, González, Fernando, Fernandez, Carmen, Ianelli, James, Mahé, JeanClaude, Mosqueira, Iago, Scott, Robert, Vazquez, Antonio
• Format: Report
• Language: English
• Published: Marine Resource Assessment and Management Group 2008
• Subjects: management strategy evaluation; fisheries management; stock-recruit; Greenland
• Online Access: http://hdl.handle.net/11427/17922

A rebuilding plan for the 2+3KLMNO Greenland halibut stock developed by NAFO Fisheries Commission has been in effect since 2004. Under the plan, ad hoc TAC reduction steps were specified to 2007. The most recent assessment of this stock indicates that the rebuilding plan has been ineffective in initiating any recovery. Fishing mortality is still at high levels and spawner biomass has remained at very low levels. Management Strategy Evaluation provides a way of examining the performance of candidate management strategies with respect to rebuilding the stock. In particular, it allows the robustness of these strategies to be considered relative to alternative operating models of the “real world”, for example the nature of the stock-recruit function for this stock. A preliminary MSE presented at the 2007 NAFO Scientific Council meeting has been updated following the NAFO SC Study Group on Rebuilding Strategies for Greenland Halibut meeting held in Vigo in February 2008. The analysis is carried out in FLR (Fisheries Libraries in R) environment, an open source framework for the development and evaluation of management strategies. A reference set of 20 possible operating models is presented, four of which are examined further. Results are presented in detail for five potential management strategies tested on these four operating models. A suite of performance statistics for this stock are used to assess these management strategies. The results of this MSE exercise are evaluated in the context of the NAFO approach to fisheries management and the potential for further progress with regard to the application of MSE on this stock in general is considered. http://www.mth.uct.ac.za/maram/pub/2008/GH_NAFO_SCR_Doc_08-25.pdf