Marine areas - Baltic herring 2025

Published 13 Oct 2026

The spawning stock biomass of herring in the Gulf of Bothnia is estimated, according to the latest stock assessment, to have fallen below the MSY B_trigger reference point in 2019. The stock decreased slightly further in 2023 as a result of the starvation period in 2020–2022, but has since recovered close to MSY B_trigger. The condition of the herring has been good since 2024, and following the recovery of individual growth, the proportion of large herring (total length over 18 cm)—which had disappeared due to starvation—has increased a little in the stock. The reference points for the stock were tightened in 2024. The herring stock in the Baltic Proper and the Gulf of Finland continued to strengthen, and the catch advice has increased from last year. The Gulf of Riga herring stock is in good condition.

Since the mid-1980s, the reproduction of the central Baltic herring stock has generally been below average. Exceptions are the years 2002, 2007, 2014, and 2024, when the previous above-average year classes were born. The 2025 and 2026 year classes appear to be average. Based on the assessment, the 2014 year class was the largest in the central Baltic herring stock since 1982.

According to ICES advice, when complying with the EU Multiannual Plan (EU MAP), catches in 2027 should be between 211,363 and 324,914 tonnes. The fact that Gulf of Riga herring is also caught in the central parts of the Baltic Proper (including the Gulf of Finland) must be taken into account in the planning and implementation of fisheries. According to the advice, fishing on herring schools migrating to spawn should not be permitted unless it has been established that the fishing method is not harmful to the herring stock.

In the winter of 2022–2023, during the benchmark assessment of the central Baltic herring stock, the calculations for the reference points (MSY B_trigger, B_pa and B_lim) changed, resulting in the stock status being assessed as weaker than before and the spawning stock biomass (SSB) being estimated as smaller than the lowest reference point (B_lim). Fishing quotas were reduced, after which the stock began to grow. In the 2026 stock assessment, the spawning stock was estimated to be as large as it last was in the mid-1980s, and it was considered possible to increase catches for the second consecutive year. With fishing in accordance with the advice, the spawning stock biomass is estimated to exceed the MSY B_trigger reference point, which was defined in winter 2022–2023, in 2027.

As in recent years, the central Baltic herring stock is most abundant in waters close to Finland—in the northern part of the Baltic Proper and in the Gulf of Finland—but scarcer in the southern Baltic Sea.

The fishing mortality of Gulf of Riga herring in age groups 3–7 was previously high, but after falling sharply in 2008–2012, it has generally remained in line with the MSY principle defined for the stock since 2010, very close to F_MSY or below (0.28). The development of the spawning stock biomass has followed strong year classes and was on an upward trend since the late 2010s, but according to a preliminary estimate, it decreased slightly in 2026. The stock is clearly larger than the long-term average. Since the late 1980s, reproduction has generally been more successful than in the 1970s and 1980s, and several record-large year classes have been born since the turn of the millennium. According to ICES advice, when complying with the EU MAP, catches in 2027 should be between 25,832 and 38,696 tonnes.

Due to local environmental conditions and intense food competition, the Gulf of Riga herring is the smallest in size in the Baltic Sea and is short-lived. Individual growth practically stops after just a few, often even 2–3, growing seasons.

Thanks to large year classes, the spawning stock of herring in the Gulf of Bothnia grew strongly from the sparse but fast-growing herring stock of the 1980s to the early 1990s, while individual growth slowed down. The spawning stock biomass peaked in the 1990s and decreased towards the turn of the millennium due to declining salinity and ecosystem changes. In the 2000s, the spawning stock biomass fluctuated between 730,000 and 900,000 tonnes. In the 2010s, the stock gradually decreased during a period of large quotas and catches. The condition factor (Fulton's) increased, but individual growth improved only slightly and has remained far below the growth seen in the 1980s. According to the latest stock assessment, the spawning stock biomass fell below the current reference point (established in 2024) in 2019.

The condition of the herring began to deteriorate in autumn 2020, and in 2021 and 2022, especially large individuals were exceptionally thin, even starved, and a large proportion of the largest individuals likely died of starvation. Spawning biomass is estimated to have fallen to its lowest level in 2023 and 2024, after which the spawning stock recovered close to the B_trigger reference point in 2025.

The recovery of the herring’s condition began during the winter season of 2022–2023, and in autumn 2024, the herring were the fattest they had been in decades, remaining in good condition in autumn 2025. The proportion of large individuals in the stock has increased, but has not yet reached a level corresponding to that of the 2010s.

According to the latest estimate, reproduction was exceptionally successful in 2002. In the 2010s, above-average year classes occurred in 2011, 2014, 2016, 2018, 2019, and, based on preliminary results, in 2024.

The abundance of herring covering all age groups observed in acoustic surveys has been above average during the period 2007–2024 in the years 2011, 2012, 2014, 2017, 2020, and 2023. The largest number of individuals in the time series was observed in 2020, while the smallest amounts of herring in the time series were observed in 2021 and 2022. In the trawl samples from autumn 2023 (the third largest number of individuals in the time series), it was noted that large individuals with a total length of over 17 cm had almost completely disappeared during the starvation period. The number of individuals in autumn 2025 was at an average level. The large differences in abundance observed in consecutive years in the acoustic surveys of the Bothnian Sea indicate that a larger proportion of the herring stock in the Bothnian Sea than in the Baltic Proper may be out of reach of the echo sounding during the surveys.

According to ICES advice, when complying with the EU MAP, catches in 2027 should be between 80,767 and 90,391 tonnes.