Applying length-based assessment methods to fishery resources in the Bay of Biscay and Iberian Coast ecoregion: Stock status and parameter sensitivity

Cousido‐Rocha, Marta; Cerviño, Santiago; Alonso‐Fernández, Alexandre; Gil, Juan; Herraiz, Isabel González; Rincón, Margarita M.; Ramos, Fernando; Rodríguez-Cabello, Cristina; Sampedro, Paz; Vila, Y.; Pennino, María Grazia

doi:10.1016/j.fishres.2021.106197

Cited by 12 publications

(7 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, an increased scaling factor can be used for the catches where misreporting could be higher. If we compare the analysis of these stocks with SPiCT with the use in FU 25 and FU 26-27 females stocks of other data limited stocks methods as Length Based Indicators (LBI) (see Cousido-Rocha et al, 2022a) we found that FU 25 females stock in 2019 was not exploited at the MSY level, albeit closer to it. Length Based Spawning Potential Ratio (LBSPR) method applied suggested that FU 25 females stock were below MSY levels above collapse in the last years (Cousido-Rocha et al, 2022a).…”

Section: Discussionmentioning

confidence: 99%

“…Besides, LBI and LBSPR models analyze each year regardless of the other years, do not take into account the spatial component, are very sensitive to different values of the input parameters (Cousido-Rocha et al, 2022a) and provide very simple results. SPiCT takes the history of the fishery into account and the input data are only catch and biomass index time series.…”

Section: Discussionmentioning

confidence: 99%

“…The depth associated with positive catch rates of Nephrops has been increasing since 1989 in all three stock areas. Nephrops movement capacity is low (Chapman and Rice, 1971) and limited by the type of sediment, so these changes could be attributed to the disappearance of Nephrops from the shallow waters more than to Nephrops displacements. Fishing effort and CPUE have been decreasing throughout the time series in the three stocks (Figure S12; ICES, 2021a).…”

Section: Stocks Statusmentioning

confidence: 99%

“…Since 2015, different data-limited stock assessment methods such as Length-Based Indicators (LBI), the Length-Based Spawning Potential Ratio (LB-SPR), the Mean Length-Based Total Mortality Estimators (MLZ), or the Separable Cohort Analysis (SCA) have been applied to the three stocks. However, available data and the stock characteristics did not meet the assumptions of these models (ICES, 2016;ICES, 2018a;ICES, 2020;Cousido-Rocha et al, 2022a).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

First Maximum Sustainable Yield advice for the Nephrops norvegicus stocks of the Northwest Iberian coast using stochastic Surplus Production model in Continuous Time (SPiCT)

et al. 2023

Self Cite

View full text Add to dashboard Cite

The assessment of the status of fisheries resources is pivotal due to the importance of marine resources in global food security and to halt the ongoing decline in marine biodiversity. Norway lobster (Nephrops norvegicus) is one of the most valuable resources in the Northeast Atlantic. However, overfishing has caused the decline of several Nephrops stocks over the last decades, particularly in the Nephrops Functional Units (FUs) 25 (NW Spain), 26-27 (NW Spain and North Portugal) and 31 (Cantabrian Sea, North Spain). Since 2003, the information provided by the very low level of landings and fishing effort of these three stocks was insufficient to carry out an adequate analytical assessment, so the base of the assessment has been the trends from commercial catch per unit effort (CPUE). The objective of this study was to carry out the first assessment of these three stocks with an analytical MSY-based model. A review of the available data was made and the stochastic Surplus Production Model in Continuous Time (SPiCT) was fitted for each FU. The results indicate an extremely low biomass for FUs 25 and 26-27 since the mid-nineties well below the reference points. For FU 31, on the other hand, estimated biomass is larger. Our findings also identified long-term temporal and spatial changes in the population dynamic of Nephrops in the Northwest Iberian coast. The results were compare with those obtained in the same stocks with other data-limited methods. Also the role of abiotic factors on the observed dynamic of the stocks was explored. The results of this study are not only relevant for the sustainable exploitation of Norway lobster stocks off the Northwest Iberian coast but provide valuable insights into the suitability and limitations of production models for the assessment of crustacean stocks in general.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Stocks Statusmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

First Maximum Sustainable Yield advice for the Nephrops norvegicus stocks of the Northwest Iberian coast using stochastic Surplus Production model in Continuous Time (SPiCT)

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similarly, LBI and GTG‐LBSPR produced similar results that were consistent with expert opinion when applied to assess stock status and trends of a snapper and grouper fishery in the Java Sea (Amorim, 2020) and in a tropical reef fishery (Babcock et al, 2018). Assessments using LBI and LBSPR together give more precision to the estimates but when the results contradict each other, the LBIs, except P mega , are more reliable than LBSPR indicators (Marta et al, 2022). The choice of a data‐limited approach should depend on the type of data available and local fishery situations, with the CMSY performing well for catch data and LBSPR for length‐frequency data (Pons et al, 2020).…”

Section: Discussionmentioning

confidence: 99%

Assessment of data‐limited fisheries: A case study of three finfish species in Chilika lagoon, India

Raghavan

Varghese

Sajina

et al. 2022

Fisheries Management Eco

View full text Add to dashboard Cite

Inland capture fisheries in many parts of the world, especially in developing nations, receive relatively low governance priority, thereby raising concerns about their sustainability. Consequently, most inland capture fisheries are data‐limited, which renders conventional capture fisheries assessment methods inapplicable for making science‐based monitoring and management decisions. Three recent data‐limited approaches for marine fish stock assessments using length frequency and catch data (Length‐Based Indicators [LBI], Growth‐Type Groups Length‐Based Spawning Potential Ratio [GTG‐LBSPR] and Catch Maximum Sustainable Yield [CMSY]), were explored for applicability to assess stock status of three commercially exploited finfish species, Daysciaena albida, Eleutheronema tetradactylum and Mugil cephalus, in Chilika lagoon, an inland water body along the east coast of India. The LBI and GTG‐LBSPR approaches are based on catch length‐frequency data, while the CMSY is based on catch‐only data. The LBI provided insight into current exploitation status of the three species in relation to sustainable fishing, the GTG‐LBSPR provided reference points (RP) for the unfished portion of spawning biomass and relative yield in relation to selectivity, and the CMSY provided RPs for MSY, biomass and fishing pressure that yield MSY, to assess stock status and fishery management decisions. All three approaches suggested that the three species were overfished in terms of catch length and quantity, which agreed with expert knowledge of the fishery in the lagoon. All three approaches can support management and policy decisions in inland fisheries and fishery management recommendations. Future research should explore and standardise such approaches to overcome data limitations in assessing and managing inland capture fisheries.

show abstract

Performance of length-based assessment in predicting small-scale multispecies fishery sustainability

Medeiros‐Leal

Santos

Peixoto

et al. 2023

Rev Fish Biol Fisheries

View full text Add to dashboard Cite

Small-scale fisheries play a critical role in food security and contribute to nearly half of reported global fish catches. However, the status of most small-scale fisheries stocks is still poor. In data-limited situations, length-based methods have been widely applied to estimate reference points and to understand stock status. This study applied three different length-based assessment methods (length-based indicators—LBI, length-based spawning potential ratio—LBSPR, and the length-based Bayesian biomass approach—LBB) to predict fisheries stock sustainability in the Azores. Overall, the three methods showed robustness for 15 out of 18 stocks assessed and agreed on their exploitation status. The results showed that 45% of the Azorean stocks were classified as sustainable stocks, 33% possible rebuilding/overfished and 22% overfishing/overfished stock status. Sensitivity analysis showed that biases on the source of initial life-history parameters, especially the asymptotic length (L∞) and the ratio of natural mortality and growth coefficient (M/k), have a stronger influence on the reference points of conservation of mature individuals (LBI), spawning potential ratio and fishing mortality (LBSPR) and the biomass relative to the maximum sustainable yield (LBB). Furthermore, sensitivity analysis indicated that, among the three methods, LBI is more robust. Our findings provide some management recommendations such as (1) catches and effort should be reduced; (2) minimum landing size should be increased; (3) minimum hook size should be increased, to be applied mainly for those stocks classified as possible rebuilding/overfished and overfishing/overfished stock status. Graphical abstract

show abstract

Applying length-based assessment methods to fishery resources in the Bay of Biscay and Iberian Coast ecoregion: Stock status and parameter sensitivity

Cited by 12 publications

References 34 publications

First Maximum Sustainable Yield advice for the Nephrops norvegicus stocks of the Northwest Iberian coast using stochastic Surplus Production model in Continuous Time (SPiCT)

First Maximum Sustainable Yield advice for the Nephrops norvegicus stocks of the Northwest Iberian coast using stochastic Surplus Production model in Continuous Time (SPiCT)

Assessment of data‐limited fisheries: A case study of three finfish species in Chilika lagoon, India

Performance of length-based assessment in predicting small-scale multispecies fishery sustainability

Contact Info

Product

Resources

About