by Nadine Kraft, Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei

Herring. Credit: Thünen Institute/Christina Waitkus

Migratory birds, sea turtles and salmon have something in common: every year, they return to their birthplaces to reproduce. A study now published in the journal Science Advances shows that Atlantic herring in the Baltic Sea also exhibit this spawning site fidelity.

For the first time, an international research team led by Dr. Dorothee Moll from the Thünen Institute of Baltic Sea Fisheries in Rostock demonstrated that herring are highly likely to spawn in the bays, lagoons and estuaries where they themselves once hatched (natal homing).

For the study, the researchers determined the chemical “fingerprint” from the fish’s ear stones (otoliths) and conducted genetic analyses to determine the fish’s origin and reproductive migrations. The results show that 56% to 73% of herring return to their birth area to reproduce, regardless of the size of the spawning area.

“This is the first evidence of pronounced spawning site fidelity in herring,” says Dr. Moll, lead author of the study. Previously, scientists assumed that younger and inexperienced herring simply joined the shoals of older fish when it’s time to reproduce, thus learning the migration routes to established spawning grounds.

“However, our results show, that the various spawning grounds along the coast are not arbitrarily interchangeable or replaceable,” explains the scientist. This once again underlines the importance of targeted coastal zone management to ensure the long-term productivity and resilience of marine ecosystems.

The Thünen Institute of Baltic Sea Fisheries has been studying the population dynamics of herring for many years. The current research continues a study published in 1997. The older theory postulated that herring shoals take in so-called “strays” on their long migrations between their feeding grounds and spawning areas, which promote genetic exchange between subpopulations and form an overarching metapopulation. Dr. Moll and her team are now able to test this hypothesis and determine the proportion of returners and strays.

In view of increasing human intervention in coastal ecosystems, these findings are of great importance: they show how closely the productivity of fish populations is linked to the preservation of local spawning grounds—and how important it is to protect these habitats specifically.

More information: Dorothee Moll et al, Direct evidence of natal homing in an Atlantic herring metapopulation, Science Advances (2025). DOI: 10.1126/sciadv.adz6746

Provided by Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei

Citation: Herring return to their birthplaces for spawning, genetic study shows (2025, November 3) retrieved 3 November 2025 from https://phys.org/news/2025-11-herring-birthplaces-spawning-genetic.html

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