Abundances indices and biological traits of juvenile salmon sampled in the Scorff river (France)

Nicolas Jeannot1, Didier Azam2, Yoann Guilloux3, Etienne Prévost4, Frédéric Marchand2, Nadine Herrard2, GBIF France5

1 INRA-U3E, Moulin des Princes, 56620, Pont-Scorff, France; 2 INRA-U3E, 65 rue de St Brieuc, CS 84215, 35042, Rennes, France; 3 FDPPMA56, Moulin des Princes, 56620, Pont-Scorff, France; 4 INRA-ECOBIOP, Aquapôle - Ibarron, 64310, St-Pée-sur-Nivelle, France; 5 GBIF France, MNHN Géologie CP48, 43 rue Buffon, 75005, Paris, France

Corresponding author(s): Nicolas Jeannot (Nicolas.jeannot@inra.fr)Didier Azam (Didier.Azam@inra.fr)Yoann Guilloux (yoannguilloux.mdp.fedepeche@orange.fr)Etienne Prévost (Etienne.Prevost@inra.fr), Frédéric Marchand (frederic.marchand@inra.fr)

Received {date}; Revised {date}; Accepted {date}; Published {date}

Citation: Combination of authors, year of data paper publication (in parentheses), Title, Journal Name, Volume, Issue number (in parentheses), and doi of the data paper.

Resource Citation

Jeannot N., Azam D., Guilloux Y. and Prévost E. 2017. Abundances and biological traits of the juveniles salmon sampled in the survey of Salmon abundance Indices in the Scorff river (France).

Abstract

A survey started in 1993 is conducted every year in early autumn (late September to early October) to quantify the abundance of juvenile Atlantic salmon in the Scorff In Brittany. The electric fishing protocol of Prévost and Baglinière (1995) is used. It targets Atlantic salmon young of the year (0+ parr), but older fish (juvenile salmon ≥1+) are also caught and included in this dataset. Sampling is restricted to areas with shallow running water flowing on coarse bottom substrate, i.e. the preferred habitat of young of the year salmon. The data consist of abundance indices and biological traits measured on the fish sampled: sex, maturity status, length, weight and age. The latter is ascertained from scale samples taken from the fish which size does not allow to determine their age unambiguously.

Keywords: Samplingevent, Population density, population distribution, catch effort, salmo salar, salmon

General description

Additional information: This data set is intended to be updated annually.

Project details

Project title: Observatoire de Recherche en Environnement des poissons diadromes sur les Fleuves Côtiers - Ecological  Research Observatory on Diadromous Fish in coastal streams
Personnel: Etienne Prévost
Funding: - INRA : French National Institute for Agricultural Research

- AFB : French Agency for Biodiversity

- FEAMP : (European Fund for Maritime Affairs and Fisheries).  Since 2017, data collected on salmon in the framework of the ORE DiaPFC have been included in the national program for the data collect in support of scientific advice for the Common Fisheries Policy (DCF - Work Plan for data collection in the fisheries and aquaculture sectors 2017-2019) for the European regulations on fisheries management.
In this context, INRA and AFB contribute to the National Work Program piloted by the DPMA of the Ministry of the Environment. This program is financially supported by FEAMP
Study area descriptions/descriptor: This infrastructure Research relies on three coastal streams of the Atlantic facade Channel, the Bresle and Oir in Normandy (Manche), the Scorff in Brittany (Morbihan) and the Nivelle in the Basque Country (Pyrenees Atlantiques).
Design description: The issue of 'Research Observatory on Diadromes Fish in Coastal Rivers (ORE DiaPFC) is to study the evolution of diadromous fish populations as a result of environmental changes (climate change and changes related to agriculture ) that affect these rivers.

Data published through GBIF: http://ipt.gbif.fr/resource?r=inra_rennes_scorff

Taxonomic coverage

Taxonomic ranks
Species: Salmo salar

Spatial coverage

General spatial coverage: The Scorff, a coastal river in Brittany (France)
Coordinates: 47°46'12''N and 48°10'12''N Latitude; 3°20'24''W and 3°15'0''W Longitude 

Temporal coverage: September 27, 1993 - October 6, 2017

Natural collections description

Collection name: Colisa - Collection of Ichtyological Samples
Collection identifier: http://147.99.222.8:8080/BDEI/
Specimen preservation method: Dried
Specimen preservation method: Other
Specimen preservation method: No treatment
Curatorial unit: Between 13200 and 13292 (Fins)
Curatorial unit: Between 478 and 478 (Scales)

Methods

Method step description: 
- . 	Fish capture was carried out with a backpack electrofishing equipment. The same gear was used since the beginning of the data collection, namely a Martin Pêcheur from DREAM Electronique, It is tuned to produce a pulsed DC with a 400 Hz frequency, 250-300 volts and a square-waveform between 4 and 10% duty cycle.	
Fishing is operated according to the following steps :	
1	Two large dip-nets with metal frames are placed facing the current, lying on the bottom, and kept at a fixed position.  
2	The anode scans an area of about 4-5 m upstream of the dip-nets in the vein of water filtered by them.
3	Fish attracted by the anode and shocked go down into the nets guided by the electrode and driven by the water flow. If necessary, the fish stuck on the bottom or in aquatic vegetation are recovered by a small hand net. 
4	Individuals are transferred into a bucket previously filled with water. 
5	The whole team moves laterally several meters out of the area that has just been disturbed by the electric field, the carrier of the electrofishing gear taking care of not to step on the area he will next explore with the anode. When a bank is reached, the progression is a few meters upstream. 
Then steps 1-5 are repeatedThe sampling at a given site stops after 5 minutes of actual fishing – i.e. the duration when the electric field is applied in the water - measured directly on the counter of the electric fishing equipment. Juvenile abundance is quantified by the number of individuals captured for a unit effort (5 minutes of fishing under the conditions specified above). 	
Biometric measurement of the fish are recorded after their anesthesia with benzocaïne. The fish length is measured from the tip of the mouth to the fork of the caudal fin (1 millimeter precision). Fish are then weighed (0.2 g precision) and maturity status is assessed by a gentle pressure on the belly that allows to get sperm in mature males. All the fish sampled are then released in their original site.
- . 	Age is verified from scale reading according to standard methods described by (Baglinière and Le Louarn, 1987) and (Richard and Bagliniere, 1990).
Study extent description: Scorff river, CdSandre=J5--0220
Latitude between 47.7718 and 48.1682; longitude between -3.2497 and -3.3404
Source latitude and longitude : 48.14 -3.283 
Last confluence point latitude and longitude : 47.7371 -3.3474 
The Scorff river is a small coastal stream of Southern Brittany (France). The main river is 78,6 Km long including 15 km of estuary. The mean gradient is 3,6%, the annual mean discharge is 5 m3 s- and the drainage basin area is 480 km2. Human activities and land use are mainly from agriculture, with some areas made moors and forests. Atlantic salmon colonization is essentially restricted to the main river over a 50 km stretch starting at the head of tide. Reproduction of Atlantic salmon takes place mostly in the main river (Bagliniere et al., 1979).The Scorff has only three larger tributaries. Up to recent years, their colonization by Atlantic salmon was restricted their down-stream end due to mill-dams.
Sampling description: In the Scorff, sampling is conducted at 42 sites spread along the mainstem and 27 spread over 12 tributaries in the area of the hydrographic network colonized by Atlantic salmon. The sites are visited once a year at the beginning of autumn (end of September to early October).

Datasets

Dataset description
Object name: Darwin Core Archive Abundances indices and biological traits of juvenile salmon sampled in the Scorff river (France)
Character encoding: UTF-8
Format name: Darwin Core Archive format
Format version: 1.0
Distribution: http://ipt.gbif.fr/archive.do?r=inra_rennes_scorff
Publication date of data: 2019-04-24
Language: English
Licences of use: Creative Commons Attribution (CC-BY) 4.0 License

Metadata language: English
Date of metadata creation: 2017-03-06
Hierarchy level: Dataset

References
Prévost E., Baglinière J.-L., 1995. Présentation et premiers éléments de mise au point d'une méthode simple d'évaluation du recrutement en juvéniles de saumon atlantique (Salmo salar) de l'année en eau courante, p. 39-48. In Gascuel D., Durand J.L., Fonteneau A., (Eds.) Les recherches françaises en évaluation quantitative et modélisation des ressources et des systèmes halieutiques. Colloques et séminaires, ORSTOM éditions, Paris.
Prévost E., Nihouarn A., 1999. Relation entre indicateur d'abondance de type CPUE et estimation de densité par enlèvements successifs pour les juvéniles de saumon atlantique (Salmo salar L.) de l'année. Bull. Fr. Pêche Piscic., 352 : 19-30.
Baglinière, J. L., and Le Louarn, H. 1987. Caractéristiques scalimétriques des principales espèces de poissons d’eau douce de France. Bulletin Français de la Pêche et de la Pisciculture: 1–39.
Richard, A., and Bagliniere, J. L. 1990. Description et interprétation des écailles de truites de mer (Salmo trutta L.) de deux rivières de Basse-Normandie : l’Orne et la Touques. Bulletin Français de la Pêche et de la Pisciculture: 239–257.
Marchand, F. et al (2017). Abundance indices and biological traits of juvenile salmon (Salmo salar) sampled in three rivers on the Atlantic and Channel coasts (France). Biodiversity Data Journal 5, e15125.