Description
Brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) were sampled in 20 lakes located along an altitudinal gradient (36 - 850 m.a.s.l.) in central Scandinavia. 10 of these lakes where trout only populations (allopatric) and in 10 trout and char co-existed. In addition, Three spined stickleback (Gasterosteus aculeatus L.) and European eel (Anguilla Anguilla L) co-occurs in most lakes below the marine transgression line. However, these species where not collected using the present gill-net series. Also, two of the lakes (Slipstikken and Grisbakktjørna) had a scares population of burbot (Lota lota L.) (catch of burbot not recorded). The sympatric lakes, with the exception of Kjerråtjønnin were sampled three times (spring 2008 – autumn 2008 – spring 2009), and the allopatric lakes were sampled two times (autumn 2008 – spring 2009). Autumn samples were collected just before ice formation and spring samples in 2008 somewhat after and 2009 just after ice breakup. At each sampling period fish were sampled with bottom gill nets (1.5 m x 25 m) with bar mesh sizes of 12.5 – 16 – 19.5 - 24 – 29 – 35 mm. Three and three nets were linked together making chains with alternating mesh sizes in order to represent all mesh sizes at different depths in each lake at each sampling period. Depths were measured at the start and end of each net. The gillnet chains were set perpendicular to the shore in the evening and hauled the next morning. The fish were frozen in plastic bags and stored at -25 °C. In the laboratory, wet mass (precision 0.1 g), fork length (precision 1 mm), sex, parasite load and maturation stage (Dahl 1917) were determined. Scale (trout) and otolith (char) samples were taken and used for age determination. In a subsample of the fish the contents of the oesophagus and the stomach were identified to various taxonomic levels and grouped into seven categories: surface insects, chironomidae, mollusca, benthic insects, benthic crustaceans, zooplankton and fish. Stomach contents and each individual fish were dried, and homogenized before quantifying 137Cs by gamma counting the samples in an integral, well-type, NaI-scintillation detector (LKBWallac Compugamma). Due to current restrictions with the DwC-A format, data and associated measurements on individual fish ((this dataset) is published separately from gill-net events and associated measurements. This dataset gives occurrence part of the dataset. Data on gill-net sampling, effort and temperature recordings are given in a separate dataset ("Gillnet test fishing and radiocaesium (Cs-137) of brown trout (Salmo trutta) and Arctic char (Salvelinus aplinus) 2008 and 2009 from 20 Central Scandinavian lakes: Events" (UUID: a6cc334b-036a-43d0-ae68-3f84a08e8d97, Alternative Identifier: http://gbif.vm.ntnu.no/ipt/resource?r=gillnet_fishing_from_20_central_scandinavian_lakes_events)
Enregistrements de données
Les données de cette ressource occurrence ont été publiées sous forme d'une Archive Darwin Core (Darwin Core Archive ou DwC-A), le format standard pour partager des données de biodiversité en tant qu'ensemble d'un ou plusieurs tableurs de données. Le tableur de données du cœur de standard (core) contient 5 701 enregistrements.
1 tableurs de données d'extension existent également. Un enregistrement d'extension fournit des informations supplémentaires sur un enregistrement du cœur de standard (core). Le nombre d'enregistrements dans chaque tableur de données d'extension est illustré ci-dessous.
Cet IPT archive les données et sert donc de dépôt de données. Les données et métadonnées de la ressource sont disponibles pour téléchargement dans la section téléchargements. Le tableau des versions liste les autres versions de chaque ressource rendues disponibles de façon publique et permet de tracer les modifications apportées à la ressource au fil du temps.
Versions
Le tableau ci-dessous n'affiche que les versions publiées de la ressource accessibles publiquement.
Comment citer
Les chercheurs doivent citer cette ressource comme suit:
Finstad A G, Berg O K, Ulvan E, Helland I, Ugedal O (2019): Gillnet test fishing and radiocaesium (Cs-137) of brown trout (Salmo trutta) and Arctic char (Salvelinus aplinus) 2008 and 2009 from 20 Central Scandinavian lakes: Occurrences. v1.3. NTNU University Museum. Dataset/Occurrence. https://gbif.vm.ntnu.no/ipt/resource?r=gillnet_fishing_from_20_central_scandinavian_lakes&v=1.3
Droits
Les chercheurs doivent respecter la déclaration de droits suivante:
L’éditeur et détenteur des droits de cette ressource est Norwegian University of Science and Technology. Ce travail est sous licence Creative Commons Attribution (CC-BY) 4.0.
Enregistrement GBIF
Cette ressource a été enregistrée sur le portail GBIF, et possède l'UUID GBIF suivante : 28c6444b-d35e-4863-a342-820a82ba63b7. Norwegian University of Science and Technology publie cette ressource, et est enregistré dans le GBIF comme éditeur de données avec l'approbation du GBIF Norway.
Mots-clé
gill-net; radioccaesium; freswhater; lakes; fish; Metadata
Contacts
- Utilisateur
- Associate Professor
- Créateur
- Professor
- Utilisateur
Couverture géographique
Central Scandinavia in a climate gradient from coast to inland.
| Enveloppe géographique | Sud Ouest [63,22, 9,33], Nord Est [64,94, 14,75] |
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Couverture taxonomique
Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta)identified to species.
| Species | Salvelinus alpinus (Arctic char), Salmo trutta (brown trout) |
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Couverture temporelle
| Date de début / Date de fin | 2008-07-01 / 2009-06-30 |
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Méthodes d'échantillonnage
At each sampling period fish were sampled with bottom gill nets (1.5 m x 25 m) with bar mesh sizes of 12.5 – 16 – 19.5 - 24 – 29 – 35 mm (Ugedal gill-net series). Three and three nets were linked together with the order of mesh sizes randomized once. Each event represent a single gill-net, with parent event referring to the gill-net chain (Ugedal series). Depths were measured at the start and end of each net. The net where set in the evening and pulled the next morning (exact time not recorded). The eventDate field represent the day of pulling the nets (i.e. the day of the sampling of the fish).
| Etendue de l'étude | Lakes where sampled two or three times (spring 2008 – autumn 2008 – spring 2009. Autumn samples were collected just before ice formation and spring samples in 2008 somewhat after and 2009 just after ice breakup. |
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Description des étapes de la méthode:
- Data where entered on paper forms in field or in lab, and punched on Microsoft xl spreadsheets. Manual control of the entered data where undertaken subsequently.
Métadonnées additionnelles
| Identifiants alternatifs | 28c6444b-d35e-4863-a342-820a82ba63b7 |
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| https://gbif.vm.ntnu.no/ipt/resource?r=gillnet_fishing_from_20_central_scandinavian_lakes |