The herring is one of the most common fish in the world, yet it remains something of a mystery. How has it managed to adapt from the icy waters of the North Atlantic to the Baltic Sea’s unique and ever-changing environment? The fish’s secrets are now beginning to be revealed through the CLUPEA research project – the first external project at BalticWaters Fish Laboratory. We spoke with Leif Andersson, a geneticist at Uppsala University, about the progress of the project so far and what the next steps are.
Although the CLUPEA research project has not yet moved into the fish research laboratory, Leif and his team are keeping busy. By examining thousands of herrings from both the Atlantic and the Baltic Sea, the researchers aim to understand how the fish has adapted to different environments. They want to pinpoint exactly which genes control key traits such as salt tolerance, temperature adaptation, spawning season, and vision.
When Leif is asked how things are going, he lights up.
– It’s going very well. We’ve made a very exciting discovery regarding four genes that must have been particularly important for the herring’s adaptation to the Baltic Sea, he explains.
The next step is to map the genetic differences between spring- and autumn-spawning Baltic Sea herring to understand what controls the timing of their spawning. This is where the BalticWaters fish research laboratory comes into play.
– Hopefully, we can bring spring-spawning herring from the Atlantic into the laboratory sometime in March. This will be a pilot project to test whether we can perform in vitro fertilizations in the lab. The pilot project is necessary so that we are ready when the real work begins in May, when the Baltic Sea herring spawn, says Leif.
Once the herring moves into the laboratory, researchers will be able to study all stages of the fish’s life in a controlled environment – down to the genetic level. The results are expected to provide new insights into how marine life adapts to environmental changes. This knowledge can not only help us understand the herring’s survival in the Baltic Sea but also contribute to more sustainable fishing and better protection of the marine environment.
Did you know…
…that the herring is one of the most abundant fish species in the world, and thanks to its great genetic variation, it is highly valuable for research on evolution and environmental adaptation.
…that Leif’s research team has previously discovered that Baltic Sea herring see better in dark waters compared to Atlantic herring, thanks to a gene affecting a specific light receptor in the retina of the Baltic herring.
…that in vitro fertilization (known as IVF) is an assisted reproduction method in which eggs are fertilized with sperm in a laboratory.
…that some of the herring’s genes function similarly in humans, meaning this research could also provide new knowledge about our own health.
The CLUPEA project – Unravelling Molecular Mechanisms Behind Adaptation to Environmental Heterogeneity and Change – runs for five years starting in 2025 and is funded by the Knut and Alice Wallenberg Foundation. BalticWaters Fish Laboratory will serve as a central resource for the project.
