Combining quantitative and qualitative models to identify functional groups for monitoring changes in the Bay of Biscay continental shelf exploited foodweb

Lassalle, Géraldine; Pasqual, Jean-Sébastien Nelva; Boët, Philippe; Rochet, Marie‐Joëlle; Trenkel, Verena M.; Niquil, Nathalie

doi:10.1093/icesjms/fst107

Cited by 11 publications

(6 citation statements)

References 37 publications

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“…; Lassalle et al . ). Fisheries can affect the entire food web, causing profound shifts in species abundance at various trophic levels, and a reduction of the number and length of pathways linking fish to primary producers (Pauly et al .…”

Section: Introductionmentioning

confidence: 97%

Trophic mechanisms underlying bentho‐demersal community recovery in the north‐east Atlantic

Arroyo

Preciado

López‐López

et al. 2017

Journal of Applied Ecology

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1. Bottom trawling is considered one of the greatest and most widespread causes of anthropogenic change in shelf seas, with major and prolonged impacts in areas with a long history of exploitation by fisheries such as the North Atlantic. Here, signs of recovery following the enforcement of regulations are increasingly being reported. 2. We examined the extent to which biological diversity and functionality are restored when fishing pressure is reduced by evaluating changes in species biomass and that of the main functional groups present in the continental platform, as obtained from systematic survey (IBTS) results. Moreover, we examined how this recovery is mirrored in the trophic organization of the affected communities by assessing variations in link density and strength of the main consumer species and investigating whether variations in species richness were paralleled by changes in network properties. Finally, we investigated whether reductions in fishing pressure (fishing mortality) were correlated with the abovementioned variations in community and trophic structure of the bentho-demersal assemblages. 3. Our results corroborate the apparent recovery of North Atlantic fishing stocks and further substantiate the improved welfare of the bentho-demersal assemblages of the Southern Bay of Biscay. Specifically, we found an increase in species richness and in the abundance of most functional groups, especially those more closely related to the benthos, following the reduction in fishing mortality. Increases in overall species richness were paralleled by an increase in the number of links and a reduction in mean interaction strength connecting the main consumer species with their prey items. This is in accordance with ecological theory and could explain the mechanism by which bentho-demersal assemblages restructure their trophic network towards more stable organizations. 4. Synthesis and applications. Detecting patterns of recovery or change to alternative stable states following stress release is essential to unravel the effects of perturbations and to design effective management strategies. Our study shows that trophic network properties provide a convincing tool to evaluate and perceive recovery patterns. The trends shown in our study appear to be related with the decline in fishing mortality resulting from the enforcement of fisheries regulations in the area. They substantiate the efficiency of these regulations as a guarantee for an ecosystem approach to fisheries management and advocate their enforcement at a wider level as a convincing measure to preserve the sustainability of marine resources and their welfare.

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Section: Introductionmentioning

confidence: 97%

Trophic mechanisms underlying bentho‐demersal community recovery in the north‐east Atlantic

Arroyo

Preciado

López‐López

et al. 2017

Journal of Applied Ecology

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“…New modeling approaches using mass-balanced models were also developed to identify ecosystem structure, function (including Ecological Network Analyses) and reaction to disturbance (Lassalle et al, 2013(Lassalle et al, , 2014aNiquil et al, 2014;Chaalali et al, 2015;Guesnet et al, 2015).…”

Section: Theory and New Approaches To Model Ecosystem Functionmentioning

confidence: 99%

Bridging the Gap Between Policy and Science in Assessing the Health Status of Marine Ecosystems

Elliott¹,

Austen²,

Berg³

et al. 2016

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“…Loop analysis can identify species responses that will occur regardless of what the interaction‐strength values are, classifying responses as positive, negative or indeterminate if either response is possible. The weighted‐predictions matrix approach builds on loop analysis, by inferring probabilities for the indeterminate species responses (Dambacher et al., ; Lassalle et al., ; Metcalf, Pember, & Bellchambers, ; Ramos‐Jiliberto, Garay‐Narváez, & Medina, ; Wildermuth, Fay, & Gaichas, ). Weightings in the matrix count the proportion of positive versus negative feedback loops between species, and high weightings are interpreted as evidential support for an indeterminate response taking a particular sign.…”

Section: Introductionmentioning

confidence: 99%

“…Baker, Holden, Plein, McCarthy, & Possingham, ), ensemble ecosystem modelling (e.g Baker, Gordon, & Bode, ), and Monte Carlo simulations in other types of models (e.g. Lassalle et al., ). To varying degrees, these methods express a philosophical idea: ignorance can be expressed in probabilistic terms, and the outcomes of doing so, also expressed as probabilities, quantify one's confidence in a prediction.…”

Section: Introductionmentioning

confidence: 99%

Dealing with high uncertainty in qualitative network models using Boolean analysis

2019

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Models for predicting ecological behaviour typically require large volumes of data for parameterisation, which is a problem because data are scarce. Qualitative modelling (QM) provides an alternative by exploring the entire range of possible parameter values. When a parameter value is completely unknown, QM typically invokes the Principle of Indifference (PoI), for example by sampling the parameter from a uniform prior distribution. However, if PoI is invoked in this probabilistic way, there may be multiple possible methods for defining a parameter space and sampling values from it, and, worryingly, two different but equally defensible methods can lead to different predictions about ecosystem responses. We investigated how probabilistic PoI can give rise to problems in QM, and developed an alternative method based on Boolean PoI that does not suffer the same limitations. We used a case study that involved predicting the responses of multiple species to the suppression of a pest. The unknown model parameters were interaction strengths between species. For the standard probabilistic method, we drew the parameters randomly from uniform (PoI) and other distributions. For our new Boolean PoI method, we instead simply specified the ranges of “possible” parameter values, and developed a Boolean analysis technique to summarise model predictions. As expected, invoking probabilistic QM yielded different predictions (species‐response probabilities) for different but equally defensible parameterisation and sampling schemes. Sometimes differences were large enough to impact decision‐making. In contrast, our new Boolean PoI approach simply classifies outcomes (species responses) as certain, possible, or impossible. Encouragingly, some species responses that were not consistently resolved under probabilistic PoI were shown by our method to be in fact governed by simple rules. Our method can also identify key species whose responses determine whole‐system outcomes. Our non‐probabilistic representation of uncertainty circumvents the philosophical problems in standard implementations of PoI for QM. Our Boolean analysis method summarises results in a way that is interpretable and potentially useful to conservation decision makers. A priority for future research is to increase the efficiency of our Boolean approach to allow it to deal with problems of higher complexity (more interactions).

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Combining quantitative and qualitative models to identify functional groups for monitoring changes in the Bay of Biscay continental shelf exploited foodweb

Cited by 11 publications

References 37 publications

Trophic mechanisms underlying bentho‐demersal community recovery in the north‐east Atlantic

Trophic mechanisms underlying bentho‐demersal community recovery in the north‐east Atlantic

Bridging the Gap Between Policy and Science in Assessing the Health Status of Marine Ecosystems

Dealing with high uncertainty in qualitative network models using Boolean analysis

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