SLU news

Nuclear bombs help to determine age for Baltic herring and sprat

Published: 06 November 2023
Herring in aquarium at BSSC, Skansen

Read an interesting article from BalticWaters where Francesca Vitale (researcher at the Institute of Marine Research), is interviewed alongside our guest researcher Allen Hia Andrews. The article focuses on their important work to increase knowledge about herring and sprat in the Baltic Sea and how the consequences of incorrect age determination can be devastating.

– The age structure of fish populations is an incredible important input information in stock assessment. We know a lot about the age of herring and sprat, but the problem is that we don’t know if the knowledge is correct, as it is based on assumptions about the accuracy of the counting method, says Francesca.

 – In the mid-1980s, there were large populations of orange roughy off the coast of New Zealand and Australia. When they were discovered, enormous quantities were fished until the number of fish rapidly declined. Fishery management had determined the age of orange roughy to be a maximum of 20-30 years, but the truth was that they could live for well over 100 years, says Allen, a research fisheries biologist and guest researcher at SLU Aqua.

Read the entire article here


The project “Understanding the life histories of small pelagic fishes for knowledge-based management decisions and a healthier Baltic Sea environment” is carried out by SLU Aqua. The project received a grant of SEK 991,900 from BalticWaters’ program to fund research projects and pre-studies.

Other projects that have been granted funding through BalticWaters

The project 'Do parasites and hypoxia prevent a recovery of Eastern Baltic cod?' led by Ulf Bergström and Yvette Heimbrand at SLU Aqua has also been granted funding of 1 million SEK for the scientific part of the project.



Francesca Vitale, researcher.
Department of Aquatic Resources, Institute of Marine Research, 010-478 40 52.