A survey started in 2007 is conducted every year in early autumn (late August to early September) to quantify the abundance of juvenile trout in the Scorff river in Brittany. The electric fishing protocol VIGITRUITE® is used. It targets trout young of the year (0+), but older fish (juvenile ≥1+) are also caught and included in this dataset. The data consist of abundance indices and biological traits measured on the fish sampled: sex, 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. The survey is carried out under the Research Observatory on Diadromes Fishes in Coastal Streamss (ERO DiaPFC) program. The data are stored in the database of the ERO. They are used to develop predictive models and tools for providing scientific advice to improve the management of this heritage species.
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 7,434 records.
1 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Jeannot N, Azam D, Guilloux Y, Quendo F, Prévost E (2022): Abundances and biological traits of the juveniles trout sampled in the survey of trout abundance Indices (VIGITRUITE®) in the Scorff river (France). v1.16. Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE). Dataset/Occurrence. http://ipt.gbif.fr/resource?r=inra_rennes_scorff&v=1.16
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The publisher and rights holder of this work is Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE). This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.
This resource has been registered with GBIF, and assigned the following GBIF UUID: 4a3722ec-9113-41e4-8648-c399d142ae68. Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF France.
Samplingevent; Population density; population distribution; catch effort; salmo trutta; trout; Occurrence
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The Scorff, a coastal river in Brittany (France)
|Bounding Coordinates||South West [47.77, -3.34], North East [48.17, -3.25]|
No Description available
|Start Date / End Date||1993-09-27 / 2022-09-16|
The Research Observatory on Diadromous Fish in Coastal Streams (ORE DiaPFC) is a research infrastructure steered by INRAE in partnership with OFB and part of the OFB-INRAE-L'Institut Agro-UPPA R&D center. It’s focused on the study of the evolution of diadromous fish populations under the influence human induced environmental changes that affect these rivers (mainly climate and effects of agriculture). Diadromous species of primary interest are salmon (Salmo salar), trout (Salmo trutta), eel (Anguilla Anguilla), shads (Alosa sp.), and lampreys (Lampetra sp. and Petromyzon marinus). These species are threatened by the consequences of human activities. They are flagship species for the biodiversity of coastal streams. Nowadays, these streams are the main refuges for diadromous fish that have disappeared or dramatically declined on larger rivers. This ERO DiaPFC is a Research Infrastructure based on four coastal streams of the Atlantic and Channel coast of France: the Bresle and the Oir in Normandy, the Scorff in Brittany and the Nivelle in the Pays Basque. These four rivers are equipped with diadromous fish trapping facilities and are thoroughly and continuously surveyed from the mid 1980s. They are twinned with experimental ecology facilities located in Rennes (Brittany) and Saint-Pée-sur-Nivelle (Pays Basque). This set of facilities is complemented by individual-based eco-genetic simulators for in silico experimentation on virtual populations.
|Title||ORE-DiaPFC Observatoire de Recherche en Environnement des poissons diadromes sur les Petits Fleuves Côtiers - ERO DiaPFC Ecological Research Observatory on Diadromous Fish in coastal streams|
|Funding||INRAE : French National Institute for Agricultural, Food en Environment Research - OFB : French Office for Biodiversity. Since 202, data collected on troutin 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 for the European regulations on fisheries management. In this context, INRAE and OFB contribute to the National Work Program piloted by the DPMA of the Ministry of the Environment. This program is financially supported by FEAMP and FEAMPA.|
|Study Area Description||ERO DiaPFC is a Research Infrastructure based on three coastal streams of the Atlantic and Channel coast of France: the Bresle and the Oir in Normandy, the Scorff in Brittany and the Nivelle in the Pays Basque|
|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.|
The personnel involved in the project:
- Principal Investigator
In the Scorff, sampling is carried out at 24 sites distributed along the main branch of the Scorff and mainly on the tributaries of the river system. Sites are visited once a year in early autumn (late August to early September).
|Study Extent||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.Trout colonisation is complete throughout the catchment. The tributaries are nurseries for young trout (0+) and sometimes have to share their habitat with Atlantic salmon (salmo salar). The Atlantic salmon population is essentially limited to the main river for a stretch of 50 km from the tidal head. Atlantic salmon spawning takes place mainly in the main river (Bagliniere et al., 1979).The Scorff has only three larger tributaries. Until recent years, their colonisation by Atlantic salmon was limited downstream due to mill dams.|
Method step description:
- At the selected station, the VIGITRUITE® protocol was designed to ensure that sampling is representative of the range of available habitat conditions, without any a priori bias towards the habitat preferences of the species. This condition is central to meet the objective of standardization, to allow comparison of results from different operators and different watercourses, and to authorize the use of density conversion abacuses per 100 m2. 1. After resetting the counter of the fishing tackle and the hand meter, the operator progresses from downstream to upstream in the watercourse. He is followed by the main operator equipped with the 2 landing nets, who must respect the travel instructions given to him by the operator, as well as by the second operator. 2. The operator follows a predefined zigzag path that takes him from one bank to the other along successive diagonals, at an angle of about 45° to the banks. Along its path, it makes electrode lines about 2 meters long, parallel to the current, and from upstream to downstream. After making the first line along the bank, the operator must visualise the next line before moving: it will be placed on the diagonal, its downstream limit always upstream of the previous line. At the end of the diagonal, if the space is too short for a line along the bank, the line will be placed on the next diagonal, always upstream of the previous line to avoid overlapping. 3. Once the location of the haul has been visualised, the operator indicates to the main fisher where to immerse his semi-circular net, i.e. upstream of the previous haul and offset on the diagonal. The fisher makes sure that the net is well placed on the bottom. If there is any difficulty in placing the net, the operator may decide to shift the position of the haul significantly. The haul is made, then the position of the next haul is displayed, and so on. The result is a sampling by regularly spaced tows from one bank to the other, covering a line of comparable watercourses regardless of the water width of the river. The two stakes marking the downstream and upstream boundaries of the fishing station are also set. 4. For each haul, the operator immerses the electrode about 2 metres upstream of the flat-bottomed landing net. The contact is made when the anode penetrates the water. The fisherman catches the visible fish with his small net, but does not move the large one. The second operator is ready to intervene in case of high abundance. During this operation, it is important that the fishermen catch only the juveniles of the year (0+) and of one year (1+). The presence of larger and older individuals (sub-adults or adults) must not cause a decrease in the team's concentration of juveniles. The hand-held competitor is incremented by one unit at the end of each haul. 5. At the end of the haul, the operator shall leave the anode at the entrance of the large landing net for 1 to 2 seconds before switching off the ignition and instructing the angler to simultaneously raise the flat-bottomed net. The haul made is counted by the hand-counter operated by the bucket holder. Once the collected fish are put in the bucket, the angler follows the operator's instructions to put the large net back in place for the next haul. 6. As the five minutes of fishing approaches, the time counter should be checked before each new haul. Station sampling shall be completed when the effective fishing time (cumulative time of electrical pulses in the water) reaches at least 5 minutes on the counter; no new electrode tows shall be started if the counter already displays 5 minutes. 7. Using the decameter, the width at the downstream stake is measured and its value noted. Then a new width measurement is made by progressing 10 meters upstream, and so on until the end of the station is approached. If necessary, the remaining distance to the upstream post (less than 10 m) is measured to complete the length measurement of the station. 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 & al (2022). Bagliniere, J.-L., Hamelet, V., Guéraud, F., Aymes, J.-C., Goulon, C., Richard, A., Josset, Q., Marchand, F., 2020. Guide to the interpretation of the scales and the estimation of the age of brown trout (Salmo trutta) from the French populations. https://professionnels.ofb.fr/en/node/836
|Collection Name||Colisa - Collection of Ichtyological Samples|
|Specimen preservation methods||Dried, Other, No treatment|
|Curatorial Units||Between 231 and 231 Fins , Between 98 and 98 Scales|
- 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.
This data set is intended to be updated annually.