Marine areas - Sprat 2025
Published 13 Oct 2026
Following the decline of cod, the Baltic sprat stock increased rapidly in the 1990s, with the spawning stock biomass peaking in 1997. Although the stock has since decreased, it has remained clearly more abundant than in the 1980s. During years of high cod abundance, when the sprat stock was small, sprat occurred in low numbers in Finnish waters. Although sprat is substantially more abundant than herring in the Baltic Sea Main Basin during its good years, it has always been scarce in the Bothnian Sea compared to herring, and it also appears to avoid the Gulf of Riga.
Following fishing quotas, the total catch of Baltic sprat in 2025 decreased from the previous year for the third consecutive time. Its fishing mortality decreased to the level of the FMSY reference point. With a second consecutive fairly strong year class (2024 and 2025), the spawning stock biomass is increasing after three particularly weak years and is well above all reference points (Bpa, Blim and MSY Btrigger).
According to the advice issued by ICES in 2026, when following the EU MAP, catches in 2027 should be between 253,819 tonnes and 332,885 tonnes. The advice is considered to be in line with the precautionary approach.
Trawl fishing for pelagic species (sprat and herring) by vessels of European Union member states is prohibited outside the baselines of coastal states (the outer limit of internal territorial waters at a distance of 12 nautical miles from the coast) in subdivisions 25–27, 28.2, and 29, as well as west of longitude 24° E in the Gulf of Finland from the beginning of May to the end of July.
In autumn acoustic surveys, the distribution of sprat has been concentrated in the northeastern and eastern parts of the Main Basin and the Gulf of Finland, whereas in May acoustic surveys, sprat has been found more evenly distributed across both the southern and northern Baltic Sea Main Basin.
Sprat in the Baltic Sea Ecosystem
The Baltic Sea sprat stock is assessed as a single fish stock. In recent years, however, autumn acoustic surveys have typically recorded high abundances of sprat in the northern Baltic Proper (in waters west of the Baltic States and in the Gulf of Finland), while in spring sprat have been more abundant in the southern parts of the Baltic Sea.
Age determination studies indicate that sprat grow more slowly in the northern Baltic Sea than in the southern Baltic Sea. This suggests that sprat do not migrate in large numbers from north to south. According to fishers, southern sprat are found in shallower waters during autumn than the depths covered by acoustic surveys.
The Decline of Cod and Oxygen Depletion Have Favoured the Growth of the Sprat Stock
The Baltic sprat stock has remained abundant since the 1990s. The collapse of the cod stock also occurred during that decade, while the herring stock in the Baltic Proper continued to decline. The reduced abundance of cod, a major predator of sprat, has probably been one factor enabling the growth of the sprat stock. Extensive oxygen-depleted bottom areas in the Baltic Proper have also indirectly favoured sprat by limiting the growth opportunities of herring.
If the Baltic Sea were in good ecological condition and the bottom waters were well oxygenated, the herring stock might be larger and the sprat stock smaller. This is because herring, which competes with sprat for zooplankton food, also requires crustacean prey associated with oxygenated bottoms in order to thrive and grow to a large size. Under current conditions, with limited benthic prey and few large zooplankton species available, herring remains relatively small.
A large sprat stock has also at times negatively affected salmon populations. When sprat abundance has been very high, the large proportion of sprat in the salmon diet has led to thiamine deficiency in salmon (the M74 syndrome). As a result, at least the reproductive capacity of salmon has been impaired.
Environmental Changes Have a Significant Impact on Baltic Fish Stocks
The impact of overfishing on changes in Baltic fish communities has probably been overstated because the full effects of a degraded habitat have not been fully understood.
In the advice provided by the International Council for the Exploration of the Sea (ICES), fisheries management aims to ensure that depleted fish stocks can recover, or at least that the conditions needed for recovery are maintained. Therefore, when the habitat of a fish species deteriorates, fisheries management must also be adapted to the reduced productivity of the stock. Such adaptations have been particularly necessary in advice concerning cod and salmon fisheries.
The status of Baltic cod, herring and perhaps also salmon stocks would very likely improve (while the sprat stock might decline) if the overall environmental condition of the Baltic Sea improved. The most serious problems are excessive nutrient loading and extensive oxygen-depleted bottom areas. The relatively limited inflow of fresh oceanic water into the Baltic Sea, and the resulting decline in salinity, have contributed to the spread of oxygen-depleted bottoms and have also made fish communities along the Finnish coast less marine in character.
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