Sawn and colored herring otolith. Photo: Yvette Heimbrandt
Age laboratories
Page reviewed:
17/03/2025
At the Department of Aquatic Resources, there are three age laboratories specialised in age and growth analyses of fish from Sweden's seas, coasts, lakes, and watercourses.
This is what we do
We perform ageing studies for research purposes and as part of international and national fish and environmental monitoring on behalf of the Swedish Agency for Marine and Water Management, county administrative boards, municipalities, and fishing associations.
We also perform age determinations and analyses on behalf of clients. Contact our age laboratories for information and pricing. Contact details can be found at the bottom of the page.
Our age laboratories
At the Institute of Marine Research, we primarily conduct age analyses for stock assessments under the EU Data Collection Framework (EU-MAP/DCF).
The species we analyse include herring, sprat, cod, haddock, plaice, and sole.
Most of the fish are collected during internationally coordinated fish surveys with research vessels and from commercial fisheries.
At present, we do not accept any external assignments for age analysis.
At the Institute of Coastal Research, we perform age analyses in three main areas:
Regional and national environmental monitoring along the coast.
Recipient control at nuclear power plants.
EU Data Collection Framework (EU-MAP/DCF).
The species we analyse include perch, sprat, eel, vendace, three-spined stickleback, salmon, European flounder, pikeperch, and round goby.
The fish we age are collected through standardised sampling surveys carried out within the various programs for regional and national environmental monitoring and recipient control programs. A portion of the fish also comes from internationally coordinated fish surveys with research vessels and from commercial fisheries.
Fees and charges
If you want to use the age laboratory in Öregrund, it costs SEK 200 per day.
If you want our help in carrying out the age analysis, we charge a standard cost and it is currently SEK 16 per sample. In addition to this, there is a cost for working time, which depends entirely on the scope of the assignment (which species to age analyse).
Contact
Contact Martina Blass if you have questions about the age laboratory in Öregrund.
At the Institute of Freshwater Research, we primarily conduct age analyses on fish in three main areas:
National environmental monitoring of small and medium-sized lakes.
Monitoring of fish stocks in Swedens large lakes: Lake Vänern, Lake Vättern, Lake Mälaren, and Lake Hjälmaren.
EU Data Collection Framework (EU-MAP/DCF).
The species we analyse include perch, roach, pikeperch, smelt, salmon, and eel.
The fish are mainly collected through standardised sampling surveys in lakes, in hydroacoustic surveys, and through collaborations with commercial fishermen.
Fees and charges
The fees for hiring us to perform age analysis vary from case to case and depend entirely on the scope of the assignment (which species to age, number, etc.).
Contact us
Contact Magnus Kokkin if you have any questions about the age laboratory at the Institute of Freshwater Research in Drottningholm.
Why do we need to know the age of fish?
Information on the age and growth of fish is required to determine the status of a fish stock, conduct stock analyses and assess how high fishing pressure a stock can withstand. Our age analyses are used for the stock estimates and advice given by the International Council for the Exploration of the Sea, ICES, and which are used as a basis for decision-making for the EU's common fisheries policy.
How age analysis works
We estimate the age of a fish using the fish's otoliths, operculum, scales and other bones, which have annual rings in the same way as trees.
Method manual for age analysis of fish
Our experts in age determination have compiled a method manual for age determination of fish. The method manual describes in detail the different stages in age determination for different species. Contact us if you want to get access to the manual (in Swedish only).
The handbook includes:
Definitions of the terminology used in age determination,
Description of appropriate equipment and procedures for different tasks,
Safety regulations,
Description of our age databases.
We use the methodology handbook as a guide during the tasks involved in age determination of fish. Age determination requires experience, which is why training and guidance from an experienced reader are necessary when onboarding new staff.
