Après une petite pause estivale, les DECODages reprennent ce Jeudi 15 Septembre à 13h avec une présentation d’Iker Pereda Agirre (doctorant AZTI-University of Basque country). Iker nous parlera de ses travaux de thèse sur l’estimation des abondances de poissons via la méthode de CKMR.
La présentation s'intitule "Abundance estimation of fisheries-species through Close-Kin Mark-Recapture: a key step for stock assessment enhancement"
Pour ceux qui veulent assister au séminaire en présentiel :
- Brest : la salle Emile Postel
- Lorient : la salle de réunions
- Nantes : Salle 2
- Rennes : Amphi Roux
Ce séminaire sera aussi accessible en distanciel sur Zoom.
Résumé
Estimation of absolute abundance and fishing mortality rate continues to be a difficult challenge for stock assessments based on conventional fisheries data such as CPUE. Close Kin Mark Recapture (CKMR) is a fishery-independent abundance estimation method that can also provide information on mortality. CKMR is based on the principle that the bigger a population is, the smaller the probability will be to find kin relationships between individuals in a random sample of that population. Yet, this probability depends on species-specific characteristics that need to be accounted for. CKMR requires fairly large sample sizes and the right mix of samples (e.g. size composition) so the logistic requirements need to be carefully considered case-by-case. Evaluating the feasibility of CKMR (eg. proposing sampling sizes) for a particular species requires prior guesstimates (e.g. from a stock assessment and/or biological studies) of key demographic information such as abundance and connectivity; those estimates would of course be refined during the actual study. The feasibility of sample collection can then be considered in relation to the value of the fishery and the management needs. In this study, we have evaluated the viability of CKMR in various commercially exploited fish species within the Atlantic Ocean: anchovy, sardine, horse mackerel, mackerel, megrim, hake, white anglerfish, yellowfin tuna and bigeye tuna. For that aim, we have gathered the biological knowledge available for each species and used it to calculate the number of samples required for each of them to successfully apply CKMR. Our analyses show that, all species seem to meet the fundamental requirements of CKMR in terms of biology. However, sample size required are substantial, and might make CKMR unattractive for some of the species. These results set the basics for future CKMR studies aimed at improving Atlantic fish stock assessment.
L’équipe d'organisation de l’animation scientifique
- 22/09/2022 : Eloïse Duval (doc. UPS-CNRS-DECOD)
- 29/09/2022 : Alejandro Ariza (chercheur DECOD)
- 06/10/2022 : François Allal (chercheur MARBEC)
- 13/10/2022 : Marine Randon (postdoc. DECOD)
- 20/10/2022 : Germain Boussarie (postdoc. DECOD)
- 24/11/2022 : Romain Lécuyer (doc. DECOD)
- 01/12/2022 : Thomas Outrequin (doc. DECOD)
- 08/12/2022 : Jan Japp Poos (prof. Wegeningen University and Research)
- 09/12/2022 : Benjamin Planque (prof. IMR ; séminaire exceptionnel un vendredi)