Challenges of management strategy evaluation for small pelagic fish: the Bay of Biscay anchovy case study

Sánchez, Sonia; Ibaibarriaga, Leire; Uriarte, Andrés; Prellezo, Raúl; Andrés, Marga; Abaunza, Pablo; Jardim, Ernesto; Lehuta, Sigrid; Pawlowski, Lionel; Roel, Beatriz

doi:10.3354/meps12602

Cited by 10 publications

(12 citation statements)

References 44 publications

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“…However, the improvement over the in-year procedure was smaller than that between the interim and the in-year advice procedures. For the Bay of Biscay anchovy, Sánchez et al (2018) showed that the benefit of the full population advice procedure over the in-year advice was also moderate, as catches increased by 15% for the same level of allowable risks.…”

Section: Discussionmentioning

confidence: 98%

“…Moving the management calendar to July-June, as soon as the abundance indices were available, allowed for the in-year management to reduce this time lag to just half a year and allowed gaining information on all age classes sustaining the second half of the year catches and all except age 1 of the next (first) half of the following year catches. This in-year management procedure has been applied successfully in the case of the Bay of Biscay anchovy where, after the stock collapse in 2005, such a change in the management calendar allowed to reopen the fishery with a management plan based on the most recent biomass estimates from the spring fishery independent surveys (Sánchez et al, 2018). Other successful applications are the joint management procedure for the multispecies South African pelagic fishery where a within-season revision of the anchovy TAC based on the most recent surveys allowed a better utilisation of the anchovy resource (De Oliveira and Butterworth, 2004) or the Australia's Prawn Fisheries where the timing of the fishing season was adjusted during the year based on the assessed status of one of the tiger prawn species (Dichmont et al, 2006b;Anon, , 2018.…”

Section: Discussionmentioning

confidence: 99%

“…This means that there was no indication of age 1 in the TAC year, which for short-lived fish might be the bulk of the population (Figure 1A). Following a similar approach to Sánchez et al (2018), we evaluated two alternative management calendars than shortened the time lag between the biomass index and the management advice: in-year advice (iny) and full population advice (fpa). In the in-year advice, the management calendar was moved to July-June, and the TAC was set as soon as the biomass index on B1+ at the beginning of the second semester was available.…”

Section: Management Proceduresmentioning

confidence: 99%

“…Their short life-span, the highly variable recruitment dynamics, the aggregative behaviour of many of them and the quick response to environmental drivers make them vulnerable to exploitation (Freón et al, 2005). The most effective management plans are based on close monitoring with fishery-independent surveys (Barange et al, 2009), short time lag between the stock assessment and the management decision (Freón et al, 2005;Sánchez et al, 2018), pre-recruitment surveys (Dichmont et al, 2006a;Sánchez et al, 2018) or the use of flexible harvest control rules to accommodate the management to the population oscillations, for example setting an initial conservative TAC with a within season adjustment when year-class strength is known (Plagányi et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

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Adapting Simple Index-Based Catch Rules for Data-Limited Stocks to Short-Lived Fish Stocks’ Characteristics

et al. 2021

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Most of the methods developed for managing data-limited stocks have been designed for long-lived species and result in a poor performance when applied to short-lived fish due to their high interannual variability of stock size (IAV). We evaluate the performance of several catch rules in managing two typical short-lived fish (anchovy-like: characterized by high natural mortality, and hence, IAV, and full maturity at age 1; and sprat/sardine-like: with medium natural mortality and IAV, being fully mature at age 2). We followed the management strategy evaluation approach implemented in FLBEIA software to test several model-free harvest control rules, where the Total Allowable Catch (TAC) is yearly modified according to the recent trends in an abundance index (n-over-m rules: means of the most recent n values over the precedent m ones). The performance of these rules was assessed across a range of settings, such as time-lags between the index availability and management implementation, and alternative restrictions on TACs’ interannual variability (the uncertainty caps, UC). Moreover, we evaluated the sensitivity of the rule performance to the operating model assumptions (stock type, productivity, recruitment variability and initial depletion level) and to the observation error of the index. In general, the shorter the lag between observations, advice and management, the bigger the catches and the smaller the biological risks. For in-year management, 1-over-m rules are reactive enough to stock fluctuations as to gradually reduce risks. The 1-over-2 rule with symmetric 80% UCs reduces catches and risks toward precautionary levels in about 10 years, faster than if applied unconstrained (i.e., without UC), whilst the ICES default 2-over-3 rule with symmetric 20% UC is not precautionary. We prove that unconstrained rules gradually reduce the fishing opportunities, with amplified effects with increasing IAV. This property explains the stronger reductions of catches and risks achieved for the anchovy compared to the sprat/sardine-like stocks for any rule and the balance between catches and risks as the index CV increases. However, to avoid unnecessary long-term losses of catches from such reduction properties, it is suggested that the rules should be applied provisionally until a better assessment and management system is set up.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Section: Management Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Adapting Simple Index-Based Catch Rules for Data-Limited Stocks to Short-Lived Fish Stocks’ Characteristics

et al. 2021

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“…This is common in single-species models but is not ubiquitous in slower, more complex multispecies and ecosystem models. The CC-MICE model (Punt et al, 2016) was designed to offer this perspective regarding California Current forage fish, and similar approaches for other species and regions also offer this valuable probabilistic approach (Cochrane et al, 1998;Sanchez et al, 2019;Siple et al, 2019;Okamoto et al, 2020).…”

Section: Outcomes and Lessons Learnedmentioning

confidence: 99%

It’s Not the Destination, It’s the Journey: Multispecies Model Ensembles for Ecosystem Approaches to Fisheries Management

et al. 2021

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As ecosystem-based fisheries management becomes more ingrained into the way fisheries agencies do business, a need for ecosystem and multispecies models arises. Yet ecosystems are complex, and model uncertainty can be large. Model ensembles have historically been used in other disciplines to address model uncertainty. To understand the benefits and limitations of multispecies model ensembles (MMEs), cases where they have been used in the United States to address fisheries management issues are reviewed. The cases include: (1) development of ecological reference points for Atlantic Menhaden, (2) the creation of time series to relate harmful algal blooms to grouper mortality in the Gulf of Mexico, and (3) fostering understanding of the role of forage fish in the California Current. Each case study briefly reviews the management issue, the models used and model synthesis approach taken, and the outcomes and lessons learned from the application of MMEs. Major conclusions drawn from these studies highlight how the act of developing an ensemble model suite can improve the credibility of multispecies models, how qualitative synthesis of projections can advance system understanding and build confidence in the absence of quantitative treatments, and how involving a diverse set of stakeholders early is useful for ensuring the utility of the models and ensemble. Procedures for review and uptake of information from single-species stock assessment models are well established, but the absence of well-defined procedures for MMEs in many fishery management decision-making bodies poses a major obstacle. The benefits and issues identified here should help accelerate the design, implementation, and utility of MMEs in applied fisheries contexts.

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Measuring the value of ecosystem-based fishery management using financial portfolio theory

Carmona

Ansuategi

Gómez

et al. 2020

Ecological Economics

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Challenges of management strategy evaluation for small pelagic fish: the Bay of Biscay anchovy case study

Cited by 10 publications

References 44 publications

Adapting Simple Index-Based Catch Rules for Data-Limited Stocks to Short-Lived Fish Stocks’ Characteristics

Adapting Simple Index-Based Catch Rules for Data-Limited Stocks to Short-Lived Fish Stocks’ Characteristics

It’s Not the Destination, It’s the Journey: Multispecies Model Ensembles for Ecosystem Approaches to Fisheries Management

Measuring the value of ecosystem-based fishery management using financial portfolio theory

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