Moving towards ecosystem-based fisheries management: Options for parameterizing multi-species biological reference points

Abstract

The case of fisheries management illustrates how the inherent structural instability of ecosystems can have deep-running policy implications. We contrast ten types of management plans to achieve maximum sustainable yields (MSY) from multiple stocks and compare their effectiveness based on a management strategy evaluation (MSE) that uses complex food webs in its operating model. Plans that target specific stock sizes (B MSY ) consistently led to higher yields than plans targeting specific fishing pressures (F MSY ). A new self-optimising control rule, introduced here for its robustness to structural instability, led to intermediate yields. Most plans outperformed single-species management plans with pressure targets set without considering multispecies interactions. However, more refined plans to "maximise the yield from each stock separately", in the sense of a Nash equilibrium, produced total yields comparable to plans aiming to maximise total harvested biomass, and were more robust to structural instability. Our analyses highlight trade-offs between yields, amenability to negotiations, pressures on biodiversity, and continuity with current approaches in the European context. Based on these results, we recommend directions for developments of EU fisheries policy.

Ensemble Projections of Future Climate Change Impacts on the Eastern Bering Sea Food Web Using a Multispecies Size Spectrum Model

“…The fishery management scenarios we considered are merely a subset of potential options and are premised on current fishery management polices remaining intact into the future. However, the framework can easily be adapted to evaluate a wider range of fishery management strategies including the effects of significant policy changes, for instance, modification or elimination of the 2 million m ton cap on TAC or the use of versions of multispecies maximum sustainable yield (Collie and Gislason, 2001;Moffitt et al, 2016) for setting ABCs rather than the currently used singlespecies version. To further increase the realism of different fishery management scenarios, methods for updating the reference SSBs that are used to calculate ABCs on annual or semi-annual time-scales would also be desirable to more closely simulate the management decision-making process.…”

Characterizing and comparing marine fisheries ecosystems in the United States: determinants of success in moving toward ecosystem-based fisheries management

“…Yet tradeoffs and ecosystem considerations are still largely ignored in most locales, at least in terms of being directly considered in the management process (Levin et al 2009;Link 2010;Patrick and Link 2015). Certainly increasing contextual information is being developed and used in many regions in the U.S. (Moffitt et al 2016;Marshall et al 2018) and elsewhere in the world (Smith et al 2007;Berghöfer et al 2008;Metcalf et al 2009;Marshak et al 2017), with successful approaches toward certain pertinent LMR management criteria. Nevertheless, formal examination of the tradeoffs facing fisheries systems remains an important issue to be addressed (Christensen and Walters 2004;Link 2010;White et al 2012;, hence the continued calls for EBFM (Fulton et al 2014;Patrick and Link 2015;Moore et al 2016;Marshall et al 2018).…”

Spatio‐temporal models of intermediate complexity for ecosystem assessments: A new tool for spatial fisheries management

“…Moffitt et al, 2016;Walters, Christensen, Martell, & Kitchell, 2005) until these differences have been explained and addressed. Moffitt et al, 2016;Walters, Christensen, Martell, & Kitchell, 2005) until these differences have been explained and addressed.…”

“…Given the differences in estimated interactions between the MICE-in-space model and previous ecosystem models using diet data, we do not recommend using the MICE-in-space model for analysing harvest trade-offs between species in the Gulf of Alaska (e.g. Moffitt et al, 2016;Walters, Christensen, Martell, & Kitchell, 2005) until these differences have been explained and addressed. However, we note that the MICE-in-space model estimates fine-scaled variation in multispecies density and also discriminates species interactions from the covariance caused by different responses to shared but unmeasured environmental drivers.…”