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Forskningsartikel2025Vetenskapligt granskadÖppen tillgång

Using the Newcomb–Benford law to detect species misreporting in mixed pelagic catches

Quesada, Eros; Cardinale, Massimiliano; Prista, Nuno; Bartolino, Valerio; Börjesson, Patrik; Bergenius Nord, Mikaela; Larson, Niklas; Hilvarsson, Annelie; Ringdahl, Katja

Sammanfattning

Modern stock assessment models used to provide management advice on sustainable catches rely on unbiased catch data. Distortion of this data, intentional or not, may increase the uncertainty in the stock perception, jeopardize the assessment of marine resources, and compromise their sustainable management with negative ecological and socio-economic effects. In this study, we apply an analysis of anomalous numbers based on the Newcomb–Benford law (NBL) to test for fisheries catch misreporting. We focus on the Swedish small pelagic fisheries targeting herring and sprat in the Baltic Sea, which are known to be highly problematic due to the pronounced mixing of the two species in their catches and the existence of potential incentives for misreporting. The analyses also include fishery-independent data from international scientific surveys, which are used as standards for the interpretation of the anomalies in the commercial catch data. We demonstrate that data from two Baltic fishery independent surveys conformed to the NBL, while Swedish commercial catch data recorded at sea (logbooks) and onshore (landing declarations) did not, indicating inaccurate reporting of commercial catches. While non-conformity to the NBL may not be considered as proof of misreporting, and to determine the intentionality of misreporting, if any, goes beyond the scope of the paper, we discuss the possible reasons for the observed deviations from the model and recommend the application of this method for quality control of fishery data. Further research (i.e. testing new tools both for detection and estimation of misreporting) should be carried on this fishery with the aim of improving the accuracy of the reported catches. Furthermore, we open the discussion to whether the management should rely on less accurate but more spatially resolved or more accurate but spatially unresolved commercial data. The application of the NBL presented in this study can be readily implemented to other stocks and fishery as a supporting tool to investigate potential misreporting and contribute to improve our understanding of self-reported fisheries data.

Nyckelord

misreporting; Newcomb–Benford law; small pelagic; baltic; stock assessment

Publicerad i

ICES Journal of Marine Science
2025, volym: 82, nummer: 4, artikelnummer: fsaf044

SLU författare

UKÄ forskningsämne

Vilt- och fiskeförvaltning

Publikationens identifierare

  • DOI: https://doi.org/10.1093/icesjms/fsaf044

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/141690