Baltic Sea Brief: When science is not enough

For a long time, BalticWaters has supported the scientific advice provided by ICES. Not because it is perfect, but because it is the best evidence available to inform decision-making. This remains the case. However, this year’s process leading up to the decision on fishing opportunities for 2027 highlights the limitations of current advice. Ahead of this year’s decision on fishing quotas, policy is taking a more cautious approach than science. For decades, the situation was the opposite.

A difference that cannot be dismissed

For herring in the central Baltic Sea, the ICES catch range for 2027 is 211,363 to 324,914 tonnes. The Commission proposes 143,860 tonnes. For sprat in the Gulf of Bothnia, the ICES range is 80,767 to 90,391 tonnes, whilst the Commission proposes 57,308 tonnes. For sprat, ICES proposes significantly increased catches, which also raises questions. The increase is largely driven by a few better year classes, whilst several uncertainties regarding catch data and stock estimates remain. For the eastern and western cod stocks, ICES recommends a continued zero catch.

The Commission justifies its more cautious approach on the basis of the poor state of the stocks, the uncertainty in the forecasts and the need for long-term recovery. Based on the same scientific evidence, the Commission carries out a broader risk assessment than ICES.

This difference highlights an issue that Sweden and several other Baltic Sea countries have been trying to address for several years: how can scientific advice better take into account the structure of fish stocks and the Baltic Sea ecosystem as a whole, rather than assessing a single stock or population in isolation?

Sweden requested more comprehensive advice already in 2022

As early as 2021, BalticWaters argued that ICES’s advice needed to be developed to better reflect the changes in the Baltic Sea’s environment and ecosystem. In 2022, Sweden took the initiative to ensure that the European Commission would take into account the environmental status of the Baltic Sea and the objective of a healthy size and age structure in fish stocks when drawing up quota proposals.

At the Agriculture and Fisheries Council in October 2022, the European Commission, Finland, Latvia, Lithuania, Poland and Sweden backed a joint statement on the deteriorating age and size structure of herring in the central Baltic Sea and the Gulf of Bothnia.

The Commission subsequently commissioned ICES to analyse, amongst other things:

• trends in the size and age structure of the stocks,
• the reasons for the decline in the numbers of large and older individuals,
• how different levels of fishing pressure affect biomass, fish size and stock composition,
• possible management measures,
• and the impact of fishing on biodiversity, food webs and the marine environment.

These were important issues. They concerned not only how much fish could be taken from an individual stock, but also how fishing affects the structure of the stocks and the surrounding ecosystem.

Four years on, the answers are still missing

When ICES reported on its work in March 2024, it was unable to put forward a concrete proposal. Instead, a roadmap was presented for continued data collection, modelling and research. When BalticWaters asked the European Commission in June 2025 how the work was progressing, the Commission was unable to provide a clear picture of how the roadmap had been followed up.

Four years after the initiative was launched, decisions on fishing quotas are therefore still being taken without the scientific advice that Sweden and several other Baltic Sea countries had called for.

This does not mean that ICES’s scientific advice is of no value. On the contrary, it is crucial to fisheries management. The problem is that the advice mainly addresses an overly narrow question: how much can be fished from an individual stock within the framework of the existing management model?

The state of the Baltic Sea calls for answers to broader questions:

• How large do fish stocks need to be to be resilient?
• How does fishing pressure affect the presence of large and older fish?
• How much herring and sprat is needed for the food web to function?
• How should climate change be taken into account when assessing the risks associated with fishing?

From roadmap to actual advice

We cannot be content merely with identifying the gaps in our knowledge. These must be translated into improved guidance and decisions that take greater account of how the entire Baltic Sea ecosystem is affected.

The European Commission itself notes that sustainable fishing in the Baltic Sea requires a healthy marine environment and that long-term objectives must be given significant weight in management decisions. The same perspective should also guide the questions ICES is tasked with answering.

Moreover, this issue is highly relevant right now. On 26–27 October, the EU’s fisheries ministers are due to decide on fishing opportunities for 2027. Before then, Sweden’s position is to be discussed in both the Environment and Agriculture Committees and the EU Committee. These bodies should give the Government a clear mandate to work with other Baltic Sea countries to ensure that the 2022 initiative actually leads to improved scientific advice.

Policy recommendations

• The European Commission is reporting on the progress made with the ICES roadmap from 2024. It must be made clear what has been implemented, what remains to be done, who is responsible for the work and when the results will be introduced.
• ICES is to be given a clear and time-bound mandate to develop its advice. The size and age of fish, the structure of stocks, food webs and the ecosystem’s recovery needs must be included in future advice.
• Precautionary principles must guide decisions until the advice has been developed. A lack of knowledge and uncertainty must not be used as arguments for higher catches. Where the consequences are uncertain, management must take the risk into account.

Sweden must now complete what began in 2022

ICES’s advice remains the best available evidence. However, the Baltic Sea needs answers to more questions than just how much can be fished from a single stock.

Sweden and several other Baltic Sea countries identified this problem as early as 2022. Four years on, the answers that were sought are still lacking.

If we are serious about rebuilding the Baltic Sea, it is not enough to manage species individually. In that case, the advice must also begin to address the questions that determine how the entire ecosystem recovers.

The brief in short

ICES’s scientific advice is the most important basis for decisions on fishing in the Baltic Sea, but current advice is still largely based on individual fish stocks.

Looking ahead to 2027, ICES’s advice allows for a significant increase in catches of, amongst others, herring and sprat. At the same time, the European Commission is proposing lower catch limits for several stocks, citing, amongst other things, the state of the stocks, uncertainties and the need for long-term recovery.

As early as 2022, Sweden, Finland, Latvia, Lithuania and Poland identified the need for improved advice that better takes into account, amongst other things, the size and age of fish, the effects of fishing pressure and the impact on the ecosystem.

In 2024, ICES presented a roadmap for further work. Four years after the initiative, no concrete steps have yet been taken towards broadening and developing the scientific advice – yet new and risky quotas continue to be set.