Atlantic salmons abundance (Ponctual Abundance Sampling PAS) - Selune Observatory

The opening of the dams should impact the functioning of Atlantic salmon populations migrating up the Sélune River and its tributaries. Restoring the river's ecological continuity will alter population flows by allowing amphihaline sea trout to migrate further upstream and native trout to move downstream and upstream of the dams. The trout population is monitored at a network of stations covering the entire Sélune basin using an abundance index, which is carried out every two years before 2021 and every year since then.

Field campaigns comply with the fishing protocol developed by INRAE and OFB. The aim of this method is to estimate the abundance of juvenile Atlantic salmon (Salmo salar) at a station (or sector). This protocol targets juveniles of the year (aged 0+) whose abundance reflects the renewal of generations within the population (or recruitment) and survival after the embryonic development phases under gravel and the first months of life in the open environment. Field campaigns are carried out by INRAE and the Manche and Ille-et-Vilaine Federations for Fishing and the Protection of the Aquatic Environment (FDAAPPMA50 and FDAAPPMA35).

This dataset provides abundance data for Atlantic salmon (0+, 1+, 2+ and cumulative) as well as the salmon abundance index (PAS) by station and fishing session.

Date (Publication): 2025-08-05T00:00:00

Edition: Mise à jour 2025

Identifier: fr-18007003900276-umrsas-selune-v_bioc_ias_ab_ias

Purpose: The purpose of this data is to estimate changes in juveile atlantic salmon abundance as part of the Sélune Observatory.

Status: Completed

Point of contact

INRAE UMR DECOD - Jean-Marc Roussel ( )

65 rue de Saint-Brieuc - CS 84215 , Rennes , 35042 , France

https://programme-selune.com/fr/

Point of contact

U3E Unité Expérimentale Ecologie Ecotoxicologie aquatique - Clarisse Boulenger ( )

65 rue de Saint-Brieuc - CS 84215 , Rennes , 35042 , France

Originator

Agence l'Eau Seine Normandie AESN - ( )

1, rue de la Pompe - BP 70087 , HEROUVILLE SAINT-CLAIR Cedex , 14203 , France

Point of contact

U3E Unité Expérimentale Ecologie Ecotoxicologie aquatique - Frédéric Marchand

Maintenance and update frequency: Annually

Place

Open data
atlantic salmon
abundance
Dam removal

Keywords

Selune river
France
Normandy

INSPIRE themes

Thésaurus INRAE

dam
poisson migrateur amphihalin
abundance index
salmon

Use limitation: Unrestricted use subject to the following compulsory wording on all distribution documents: "Source: INRAE - DECOD - U3E".

Use limitation: Open license: https://www.etalab.gouv.fr/licence-ouverte-open-licence

Access constraints: Other restrictions

Use constraints: License

Other constraints: No public access restrictions

Spatial representation type: Vector

Denominator: 25000

Metadata language: fre

Topic category

Environment

Begin date: 2012-09-02

End date: 2027-12-31

Reference system identifier: RGF93 / Lambert-93 (EPSG:2154)

Geometric object type: Point

Distributor

Distributor

UMR 1069 SAS INRA - Agrocampus Ouest - Pole GéoSAS

65 rue de Saint-Brieuc , Rennes cedex , 35042 , France

Name: ESRI Shapefile

Version: 1.0

OnLine resource

v_bioc_ias_ab_ias ( OGC:WMS )

Abondances en saumons atlantiques (IAS) - Observatoire Sélune

OnLine resource

Abundance of Atlantic salmon (IAS) - Observatoire Sélune ( WWW:DOWNLOAD-1.0-http--download )

Download "Abundance of Atlantic salmon (IAS) - Observatoire Sélune" in Shapefile format

OnLine resource: Observatoire Sélune ( WWW:LINK-1.0-http--link )

OnLine resource

Abundance of Atlantic salmon (IAS/SAI) - Observatoire Sélune ( WWW:DOWNLOAD-1.0-http--download )

Download "Abundance of Atlantic salmon (IAS/SAI) - Observatoire Sélune" in CSV format

OnLine resource: Dispersion and (re)colonization of the Sélune and its tributaries ( WWW:LINK-1.0-http--link )

OnLine resource: Activity report on the Sélune aquatic biocenoses observatory 2019-2021 ( WWW:LINK-1.0-http--link )

OnLine resource: Observatoire des biocénoses aquatiques de la Sélune - 2022 activity report ( WWW:LINK-1.0-http--link )

OnLine resource: Sélune aquatic biocenoses observatory - 2023 activity report ( WWW:LINK-1.0-http--link )

OnLine resource: Indice d'abondance saumon (IAS) ( WWW:LINK-1.0-http--link )

OnLine resource: Rapport d'activités 2024 de l'Observatoire des biocénoses aquatiques de la Sélune ( WWW:LINK-1.0-http--link )

Hierarchy level: Dataset

Conformance result

Date (Publication): 2013-12-10

Explanation: Non évalué

Pass: No

Statement: Monitoring of amphihaline fish populations in the Sélune is carried out on the main course and its tributaries, both upstream and downstream of the old dams. This allows us to understand the dynamics of these populations before, during and after the dams were demolished. Brown trout, Atlantic salmon, European eel and lamprey (marine, river and brook) are species of high conservation importance. Populations are monitored using various inventory protocols (electrofishing, trapping, DNAe) supplemented by sampling to better characterise the populations (genetics, scalimetry).

The objective of this monitoring is:

- to estimate the recruitment level in 0+ and 1+, the evolution of cohorts, abundances and densities of Atlantic salmon (Salmo salar);

- monitor biometrics (measurements, scale sampling and scalimetric readings) at reference stations;

- study intra- and inter-population genetic structure and the impact of individuals migrating downstream and upstream of dams on the entire population (fin sampling).

Sampling has been carried out annually since 2022 and biannually prior to that.

The protocol implemented is the protocol "Gaétan Pottier, Frédéric Marchand, Sabrina Servant, Etienne Prévost. Salmon abundance index (IAS). Guides and Protocols Collection. Scientific electrofishing in continental aquatic environments,

INRAE; OFB, 2022. ffhal-03757386".

The stations (also known as study sectors) were located using a hiking GPS (expected planimetric accuracy <= 20 m).