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
Citation
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: Events. Version 1.3. Norwegian University of Science and Technology. Sampling event dataset https://doi.org/10.15468/qsmqlf accessed via GBIF.org on 2025-05-18.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 is published separately from gill-net events and associated measurements (this dataset). This DwC-A gives the event part of the dataset. Data on occurrences and measurements and traits of individual fish is 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: Occurrences" (UUID: 28c6444b-d35e-4863-a342-820a82ba63b7, Alternative Identifier: http://gbif.vm.ntnu.no/ipt/resource?r=gillnet_fishing_from_20_central_scandinavian_lakes)
Sampling Description
Study Extent
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.Sampling
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).Method steps
- 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.
Taxonomic Coverages
Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta)identified to species.
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Salvelinus alpinuscommon name: Arctic char rank: species
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Salmo truttacommon name: brown trout rank: species
Geographic Coverages
Central Scandinavia in a climate gradient from coast to inland.
Bibliographic Citations
Contacts
Anders Gravbrøt Finstadoriginator
position: Associate Professor
Norwegian University of Science and Technology, Department of Natural History
NO
email: anders.finstad@ntnu.no
Ole Kristian Berg
originator
position: Professor
Norwegian Univeristy of Science and Technology, Department of Biology
NO
email: ole.berg@ntnu.no
Eva Ulvan
originator
position: Research Tecnician
Norwegian Institute for Nature Research
email: eva.ulvan@ntnu.no
Ingeborg Helland
originator
position: Research Scientist
Norwegian Institute for Nature Research
NO
email: ingeborg.helland@nina.no
Ola Ugedal
originator
position: Senior Researcher
Norwegian Institute for Nature Resarch
NO
email: ola.ugedal@ntnu.no
Anders Gravbrøt Finstad
metadata author
position: Associate Professor
Norwegian University of Science and Technology, Department of Natural History
NO
email: anders.finstad@ntnu.no
Anders Gravbrøt Finstad
user
email: anders.finstad@ntnu.no
Anders Gravbrøt Finstad
administrative point of contact
position: Associate Professor
Norwegian University of Science and Technology, Department of Natural History
email: anders.finstad@ntnu.no