# Investigating the demogenetic responses of exploited Atlantic salmon populations to climate change

Mathieu Buoro, Julien Papaix, Cyril Piou, Etienne Prévost

► To cite this version:

Mathieu Buoro, Julien Papaix, Cyril Piou, Etienne Prévost. Investigating the demogenetic responses of exploited Atlantic salmon populations to climate change. NASCO Symposium: Managing the Atlantic salmon in a rapidly changing environment. Management Challenges and Possibles Responses, Jun 2019, Tromso, Norway. 2019. [hal-02184261](https://hal.science/hal-02184261)

HAL Id: hal-02184261

https://hal.science/hal-02184261

Submitted on 5 Jun 2020

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INRA
SCIENCE & IMPACT

# Investigating the demogenetic responses of exploited Atlantic salmon populations to climate change

AGENCE FRANÇAISE
POUR LA BIODIVERSITÉ

ÉTABLISSEMENT PUBLIC DE L'ÉTAT

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Mathieu Buoro, Julien Papaïx, Cyril Piou and Etienne Prévost

**A demo-genetic individual-based model for Atlantic salmon populations** (IBASAM, Piou & Prévost 2012)

→ mimics a small population typical of french coastal streams

→ connect demo-genetic dynamics with biotic (e.g. fisheries) & abiotic factors (e.g. Water temperature, Flow)

## Effects of Climate Change

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## Effects of selective fisheries

(e.g Grilse vs Multiple
Sea Winter fish)

A) Exploitation rates tend to decrease under CC
Selective fisheries worsen the effect of CC

Number of anadromous individuals captured

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Number of Smolt

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B) Effect of CC on population size
No impact of selective fisheries

C) CC & selective fisheries induce phenotypic changes

Proportion of MSW returning to the river

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Genotype of maturing threshold for anadromous female

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D) No significant effect of CC
But selective fisheries induced genetic changes (females)

**Conclusion:** A. salmon population size and composition (age structure) could be severely affected under CC and no selective exploitation strategies mitigate the effects of CC
But current selective exploitation of Multiple Sea Winter fish could worsens the effects of CC

**Perspectives:** Explore the potential of management strategies that would be unselective and that would increase intra-population biodiversity, favoring the "portfolio effect" and resilience to CC.

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INRA
SCIENCE & IMPACT

ECOBIOP, INRA, Univ.Pau & Pays Adour
Aquapôle - Quartier Ibarron
n°173, RD 918 - route de St Jean de Luz
64310 St Pée sur Nivelle, France
www.ecobiop.com

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@ecobiop

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