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Metadatabase view - dataset: Life-history data on Hunder brown trout (Salmo trutta) from Lake Mjøsa, Norway

General information

dataset entry ID:
FWM_7
name of the dataset:
full name of the dataset:
Life-history data on Hunder brown trout (Salmo trutta) from Lake Mjøsa, Norway
dataset short name:
Life-history data on Hunder trout
type of dataset (more information):
species (taxonomic group) per site database including environmental information
specify:
Life-history (age, growth, migration, spawning)
data type:
point data/observation data, descriptive data
short description of the dataset/summary:
The dataset contains individual data for almost 8,000 brown trout (Salmo trutta L., 1758) captured during their spawning migration from Lake Mjøsa to the main tributary River Gudbrandsdalslågen in Norway during the period 1966 to 2005. These individuals belong to the large-sized piscivorous population of brown trout named Hunderørret (Hunder brown trout). A majority of these trout spawn upstream the waterfall Hunderfossen. Ascending this large waterfall, the migration length and characteristics of the spawning areas, are probably selection drivers for the large body sizes this population achieves compared to any other populations of piscivorous brown trout spawning in other rivers draining to Lake Mjøsa.

A hydropower dam was established at Hunderfossen between 1961 and 1964, causing a migration barrier for the Hunder brown trout. A fish ladder was also built, making the ascent possible from 1966, but not without negative effects (Aass 1990). The functionality seems to vary due to water temperature and water flow (Jensen & Aass 1995). The body size seems to affect the success of both entering and ascending the ladder. Additionally, the dam reduced survival of both smolt and kelt, due to predation in the dammed area and turbine passage mortality during downstream migration. The damming also reduced the areas of productive fish habitats in the river both upstream and downstream the dam (Aass et al. 1989).

When the fish ladder was opened, allowing the spawners to pass the dam, a capture-mark-recapture program was initiated. Trap capture, individual measurements, tagging, scale sampling and registration of recaptured repeated spawners in the fish ladder, were then implemented in a monitoring program. All spawners caught in the trap were individually measured and tagged with numbered Carlin tags (Carlin 1955).

To abate the reduced natural production of Hunder brown trout in the regulated river, a stocking program was initiated during the mid-1960s. The stocked fish are mainly released as 2-years old both in the river and directly into the lake (15,000-20,000 individuals per year). The stocked fish also returns to the river on spawning runs as mature adults. This long-time data series has been continued more or less unchanged until it was terminated in 2016. All stocked brown trout were tagged by cutting the adipose fin prior to release. To evaluate and optimize the stocking strategy, a large number of stocked smolt individuals were also tagged. Hence more than 30,000 individuals (both wild and stocked, spawners and smolts) have been marked individually with Carlin tags before release both upstream and downstream the Hunderfossen dam during 1966-2015. For a subset of these fish, approximately 8,000 individuals who climbed the fish ladder between 1966 and 2005, information on age, growth, time of migration and spawning history has been obtained from schlerochronological analysis of the sampled scales. This data has also been used to back-calculate yearly growth and to identify important life-history information such as hatching year, growth in river, age and size at smoltification, growth in lake, age and size at sexual maturation, and number of spawning events (e.g. Haugen et al. 2008).

Based on the 1966-2005 data the Hunder brown trout typically spend their first three to five years as parr in the river before migrating downstream to Lake Mjøsa (corresponding to smoltification and seaward migration in anadromous salmon and trout). In the lake they typically prey on fish for two to four years before maturation and migration back to the river to spawn. The Hunder brown trout typically perform biennial spawning runs and average age at first spawning run is ca. 7 years. Average size at first spawning run is ca. 3.5 kg and 65 cm. The Hunder brown trout seem to have a potential maximum life span of 15-20 years and a potential maximum size of 15-20 kg and >100 cm. However, less than 10% of the spawners reach age above 10 years, and less than 1% of the spawners reach weight above 10 kg.
science keywords according to GCMD:
topic:
Agriculture, Biosphere, Biological Classification, Climate Indicators, Human Dimensions, Terrestrial Hydrosphere
keywords:
lake, brown trout, Salmo trutta, hydropower dam, migration, growth, spawning, capture-mark-recapture, schlerochronology, scales, smoltification, monitoring, fishing, Hunderfossen, Hunder trout, age
ISO topic category according to ISO 19115:
Farming, Biota, Climatology/Meteorology/Atmosphere, Economy, Elevation, Environment, Inland Waters, Location, Society, Structure, Utilities/Communications

Technical and administrative specifications

data format:
Access
operating system:
all Windows systems
English
specify:
Originally Norwegian, translated to English.
current access level:
restricted access
others/details:
The dataset is currently not publicly available, but may be obtained on request, on certain conditions.
currently available through GBIF:
no
exchange planned:
no
data in data repository:
no
Do you plan to publish the data on the Freshwater Biodiversity Data Portal:
no
comments:
Data used in publications will be made available in data repositories as specified in the publications.
update level:
update planned
others/details:
The life-history data are obtained from fish scale samples during 1966-2005. A large amount of additional scales have been sampled and stored, but not yet analysed (2006-2015).
type:
internal description
language:
English
others/details:
More information is also available in various reports (in Norwegian).
contact details:
metadata contact person:

first, last name:
Atle
 
Rustadbakken
phone:
+47 91639398
email:
atle@rustadbakken.no
institution:
The Environment Agency, County Governor of Hedmark
address:
P. O. box 4034
postal code, city:
2306
 
Hamar
country
Norway
https://www.fylkesmannen.no/en/Hedmark/Climate-and-the-environment/
technical contact person:

Jannicke
 
Moe
+47 90898108
jmo@niva.no
institution:
Norwegian Institute for Water Research (NIVA)
address:
Gaustadalléen 21
postal code, city:
0349 Oslo
country:
Norway
web address:
http://www.niva.no/se-ansatt?navn=Jannicke%20Moe
scientific contact person:

first, last name:
Per
 
Aass
phone:
+47 64940685
email:
per.aass@nhm.uio.no
institution:
Zoological Museum, The Natural History Museums and Botanical Garden, University of Oslo, Oslo, Norway
address:
Sars gate 1
postal code, city:
0562 Oslo
country:
Norway
web address:
http://www.nhm.uio.no/english/
comments:
Per Aass is retired, but affiliated at the Zoological Museum of the University of Oslo.

Intellectual property rights and citation

dataset creator (data compiler):
contact name:
Atle Rustadbakken
contact email:
atle@rustadbakken.no
contact institution:
The Environment Agency, County Governor of Hedmark
data contributors to/owners of this dataset:
multiple
number:
2
data contributor/owner 1
contact name:
Atle Rustadbakken
contact email:
atle@rustadbakken.no
contact institute:
County Governor of Hedmark
criteria for using this part of the dataset:
The dataset needs to be requested from dataset creator with specific conditions of use.

comments:
The Norwegian Institute for Water Research (NIVA) by Jannicke Moe has been given the administrator rights for a period of five years (2016-2020) with option for prolongation.
data contributor/owner 2
contact name:
Per Aass
contact email:
per.aass@nhm.uio.no
contact institute:
University of Oslo
criteria for using this part of the dataset:
The dataset needs to be requested from dataset creator with specific conditions of use.

comments:
As for data contributor/owner 1.
citation of this dataset:
author(s):
Aass, P. & Rustadbakken, A.
title:
Life-history data on Hunder brown trout (Salmo trutta) from Lake Mjøsa, Norway (dataset)
year:
2017
version (if applicable):
1
citation of the metadata:
author(s):
Aass P., Rustadbakken A., Moe S.J., Lund E. & Qvenild T.
title and journal (name, number, pages):
Life-history data on Hunder brown trout (Salmo trutta) from Lake Mjøsa, Norway. Freshwater Metadata Journal 0: 0-0
year:
0000
doi (if applicable):
https://doi.org/10.15504/fmj.0000.0

reference 1:
author(s):
Haugen, T.O., Aass, P., Stenseth, N.C. & Vøllestad, L.A.,
title:
Changes in selection and evolutionary responses in migratory brown trout following the construction of a fish ladder. Evolutionary Applications. 1: 319-355.
year:
2008
reference 2:
author(s):
Aass, P., Sondrup Nielsen, P. & Brabrand, Å.
title:
Effects of river regulation on the structure of fast-growing brown trout (Salmo trutta L.) population. Regulated Rivers: Research & Management 3: 255-266.
year:
1989
reference 3:
author(s):
Jensen, A. J. & Aass, P.
title:
Migration of a fast-growning population of brown trout (Salmo trutta) through a fish ladder in relation to water flow and water temperature. Regulated Rivers: Research & Management 10: 217-228.
year:
1995
reference 4:
author(s):
Løvik, J.E., Skjelbred, B., Eriksen, T.E. & Kile, M.
title:
Tiltaksorientert overvåking i vannområde Mjøsa. Årsrapport for 2015. Norsk institutt for vannforskning: NIVA-rapport 7028-2016. 105 s. (in Norwegian)
year:
2016
reference 5:
author(s):
Hobæk, A., Løvik, J.E., Rohrlack, T., Moe, S.J., Grung, M., Bennion, H., Clarke, G. & Piliposyan, G.T.
title:
Eutrophication, recovery and temperature in Lake Mjøsa: detecting trends with monitoring data and sediment records. Freshwater Biology 57: 1998-2014.
year:
2012
reference 6:
author(s):
Løvik, J.E. & Moe, S.J.
title:
Time series of plankton data from Lake Mjøsa, Norway. Freswhater Metadata Journal 18: 1-9.
year:
2016
doi:
10.15504/fmj.2016.18
reference 7:
author(s):
Aass, P.
title:
Utsetting av Hunderørret i Mjøsa og Lågen, 1965-1989. Fylkesmannen i Oppland, Miljøvernavdelingen. (in Norwegian)
year:
1990
reference 8:
author(s):
Panfili, J., De Pontual, H., Troadec, H. & Wright, P.J. (eds.)
title:
Manual of fish sclerochronology. Brest, France: Ifremer-lRD coedition, 464 p.
year:
2002
reference 9:
author(s):
Carlin, B.
title:
Tagging of salmon smolts in the river Lagan. Rep. Inst. Freshwat. Res. Drott. 36: 57–74
year:
1955

General data specifications

regional coverage of the dataset:
scale of the dataset:
catchment
continents:
Europe
southernmost latitude [°]:
60.400
northernmost latitude [°]:
61.220
westernmost longitude [°]:
10.433
easternmost longitude [°]:
11.294
        
minimum altitude:
123
 
metres
maximum altitude:
175
 
metres
Europe: Norway
Group C: temperate/mesothermal climates
 
Europe:
Northern Baltic Drainages
comments:
Capture, mark and recapture data of Hunder trout (without information on growth and spawning) are available for a larger number of individuals (30,000). These data will be described in a separate metadata paper.

Site specifications

coordinate system/grid data:
latitude/longitude, format: DD
datum (e.g. WGS84):
WGS84
grid data available:
no
comments:
For most data points a location is reported, but not coordinates.
site coding available:
no
 
number of sites:
<100
comments:
A large number of sites have been reported. In addition to the original site names, the sites are aggregated to larger regions (e.g. "lake", "river above dam" or "river below dam").

Climate and environmental data

climate related data:
available per:
per site
available parameters:
mean annual temperature January, July
data source:
www.met.no
available parameters:
mean annual temperature for each month
data source:
www.met.no
available parameters:
minimal, maximal and mean winter and summer temperatures
data source:
www.met.no
available parameters:
daily air temperatures
data source:
www.met.no
available parameters:
mean annual precipitation
data source:
www.met.no
available parameters:
winter and summer precipitation
data source:
www.met.no
available parameters:
mean discharge
data source:
www.nve.no
comments:
Daily meteorological data can be downloaded from eklima.met.no, stations Kise (12550) and Toten (11500).

environmental data:
available parameters per catchment:
catchment size
data source:
www.vann-nett.no
available parameters per catchment:
catchment geology
data source:
www.ngu.no
available parameters per catchment:
catchment land cover/land use
data source:
Løvik et al. 2016
available parameters per catchment:
population density
data source:
Hobæk et al. 2012
available parameters per catchment:
presence of barriers/dams/reservoirs (fragmentation)
data source:
www.nve.no
available parameters per catchment:
hydrological regime/flow regime
data source:
www.nve.no
available parameters per site:
catchment land use upstream of sampling site
data source:
Løvik et al. 2016
available parameters per site:
information on water uses (e.g., irrigation, fish ponds)
data source:
Løvik et al. 2016
available parameters per site:
distance to next migration barrier upstream
data source:
www.nve.no
available parameters per site:
distance to next migration barrier downstream
data source:
www.nve.no
available parameters per site:
distance to the next lake upstream
data source:
www.nve.no
available parameters per site:
distance to the next main village/town upstream
data source:
www.norgeskart.no
available parameters per site:
river length
data source:
www.nve.no
available parameters per site:
distance to source
data source:
www.nve.no
available parameters per site:
distance to mouth
data source:
www.nve.no
available parameters per site:
stream order (according to Strahler)
data source:
www.nve.no
available parameters per site:
slope
data source:
www.nve.no
available parameters per site:
altitude
data source:
www.nve.no
available parameters per site:
hydrological regime/flow regime
data source:
www.nve.no
available parameters per site:
discharge
data source:
www.nve.no
available parameters per site:
maximum depth
data source:
www.vann-nett.no
available parameters per site:
mean depth
data source:
www.vann-nett.no
physico-chemistry data:
total P, nitrate, total N, hardness, alkalinity, TOC (total organic carbon), water temperature, pH, conductivity, chlorophyll, colour, Secci disc depth, thermocline depth
other physico-chemical parameters:
Other environmental data are available from NIVA (described by Løvik & Moe 2016). Other parameters (lake data): E. coli (2009-2011), ice cover (1949-2009), primary production, SiO2, turbidity.
availability of physico-chemical data, if there is more than one sample per site:
per sample
comments:
For lake data, most physico-chemical parameters are available from 1972 to present.
reference sites available:
no
available stressor types:
stressorrestored sites availabledata before/after restoration availablestressor gradient availablecomments
eutrophication
yes
yes
yes
 
organic pollution
no
no
no
 
toxic stress
no
no
no
 
hydrologic stress (e.g. impoundment, flow velocity reduction, hydropeaking, water abstraction, flow velocity increase)
yes
no
yes
Hunderfossen dam constructed in 1961-1964
thermal stress
yes
no
yes
Lake temperature has increased during the monitoring period.

Biological data

biological data origin:
from sampling; specify project:
Monitoring program with annually registration and tagging of migrating trout in the fish ladder since 1966; various projects and funding sources.
organism group addressed:
fish
comments:
Data on other organism groups from Lake Mjøsa (phytoplankton, zooplankton) and River Gudbrandsdalslågen (phytobenthos, macroinvertebrates) are available from other sources (see Løvik et al. 2016, Løvik & Moe 2016).

Sample specifications/sample resolution

fish

sample information:
covered timeframe:

year from - to:
1966 - 2005
historical data:
yes
palaeo data:
no
season:
autumn
temporal resolution/frequency of sampling:
per year
time series data:
yes
comments:
Most of the samples were taken in autumn, when fish are caught in the fish ladder during spawning migration. The data can be considered a time series since the same method has been applied to monitor a population over a long period of time.
taxonomic resolution:
species
percentage of species level data:
100
comments:
All data are on one species (brown trout, Salmo trutta L.), from one population (Hunder brown trout).
taxonomic coding:
species name
Salmo trutta
sample specifications:
quantitative (abundance data), presence/absence
yes
7381
The fish were captured either in the fish ladder (and usually released), or by fishing (and usually killed). Information on capture location, date and method were reported for individually marked fish. Ascending trout were trapped in the fish ladder at Hunderfossen hydropower dam on their spawning run. After registration of length and weight, some 4-6 scales were sampled with a small forceps. Scales were sampled from the area above the lateral line between the dorsal and the adipose fins. The fish were sexed based on secondary sex characteristics. The origin (wild or stocked) was registered based on whether the adipose fin was intact or not (removed = stocked). After registration and sampling, the fish were individually tagged with Carlin tags, consisting of a disc with information and a stainless steel thread to fix it to the fish (Carlin 1955). After tagging the fish were released into the fish ladder above the trap allowing them to pass the dam and migrate to their spawning areas. However, a number of fish were each year held in a river pool until time of spawning. These fish were used as brood fish in the stocking program and the fertilized eggs were placed in a hatchery located next to the dam. The collected scales were stored dry in paper envelopes until preparation and reading. The majority of the scales were impressed on clear cellulose acetate plastic slides. These slides were analyzed on a microfilm projector. The last two years of available samples, 2004 and 2005, were digitized for computer-based reading and measuring. The scales add sclerites as the fish grow. During periods of fast growth the distance between the sclerites are larger than during slow growth periods. Since fish are ectoterms, winter growth is considerably slower than summer growth at this latitude. Annuli are end-of-winter checks that represents the start of a new growth season. The age of the fish was determined by counting the number of annuli in the scales. Based on the assumption that scale radius growth is linearly correlated to the body growth, it is possible to back-calculate the size of the fish during each year of its life. As annuli checks identifies seasonal patterns in the scales, the growth pattern can also reveal time of niche shifts. The age at migration from river to lake often corresponds to the shift between invertebrate and fish diet. Fish diet normally results in faster growth and the switch is therefore detectable in the sclerite pattern. Hence, age at smoltification can also be determined from scale reading. Finally, spawning also creates checks in the scale. The standard output from a scale analysis of the Hunder trout is therefore river age and lake age (which sum to total age), yearly river growth and yearly lake growth, age at smoltification, age at maturity and number and time of spawning runs.
Panfili et al. 2002
Capture of individual fish (capture-mark-recapture).
Any location in Lake Mjøsa and its main tributary River Gudbrandsdalslågen, including the trap in the fish ladder in Hunderfossen waterfall.
other important sample related informations:
Annually tagging and registering of all upstream migrating spawners at Hunderfossen and typical biennial spawning have resulted in a number of individuals sampled for scales at several occasions together with individual measurements of body length. We can compare back-calculated length at a given year with manually measured body lengths that have been collected on earlier spawning runs of the same fish. We can also calculate the precision and variability of the back-calculated year-specific body lengths on a number of scales sampled at several spawning occasions. The amount of fish with repeated scale sampling and measurements in this dataset allows us to validate the back-calculations against ground truth data.

Other specifications

GIS layers, shapes related to the dataset:
no data available
yes
yes
quality control procedures:
Were any quality control procedures applied to your dataset?
no
comments:
The authors have contributed as follows:
Per Aass initiated this important monitoring program when the dam was constructed, and was in charge of the tagging of fish in the fish ladder for several years. Tore Qvenild has supported with computer assistance, digitizing and establishing the first version of the database and early stage analysis of these data. Atle Rustadbakken has been responsible for data cleaning and data compilation. He has also worked closely together with P. Aass on the age and growth analyses of the scales from thousands of trout. Espen Lund has also been involved in the data cleaning process, developing digital documentation, the analysis process and reading growth structures from fish together with A. Rustadbakken. Jannicke Moe has been responsible for constructing a relational database structure in Microsoft Access, importing the data from various Microsoft Excel files, and exporting data for sharing with other researchers.

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