Published 2024-06-05

Photo: Pixabay

Perhaps the most startling news in the latest ICES advice for next year's Baltic Sea fisheries, published on Friday, is that the central Baltic herring stock is considered to be ready for a sharp increase in fishing pressure in 2025. 

Just last year, ICES assessed the stock to be at or below the minimum sustainable limit (Blim) and advised a maximum quota of 52,500 tonnes. The European Commission proposed to stop all targeted fishing on both the central Baltic herring and the Gulf of Bothnia herring, in line with the provisions of the EU multiannual management plan (MAP) for cod, herring and sprat fisheries in the Baltic Sea. 

This year, ICES believes that the catch quota (TAC) for central Baltic herring can be increased to a maximum of 125 344 tonnes – and still remain within the management plan's MSY-based range of fishing mortality (F-values). 

The large swing, according to ICES, is because their estimates suggest that recruitment (the addition of young fish to the stock) appears to have increased, and that spawning stock biomass (the number of mature fish) has grown and is now just above Blim. 

Baltic Sea Centre's fisheries scientists, Sara Söderström and Henrik Svedäng, are sceptical about the new scientific guidelines from ICES. 

Sara Söderström

‘These are rather uncertain forecasts. Even if the stock has actually increased slightly from one year to the next, I hope that the politicians who decide on next year's quotas will consider whether it is wise to fish it all up immediately, or if it is better to let the stock grow further,’ says Sara Söderström.

‘Irresponsible’

Henrik Svedäng agrees and believes that it is irresponsible and far from the precautionary principle to open up for greatly increased fishing on a herring stock that is still in poor condition, and where the forecasts are uncertain.  

‘ICES' reasoning is not only incomprehensible but also irresponsible. They have introduced a new model to estimate the stock and according to it, there is a chance that the stock has grown just above the minimum biological sustainable limit. But the uncertainties are still large. And even if the forecast is correct, the spawning stock biomass is still very low. On this basis ICES is building hope that the stock can withstand a TAC increase of as much as 139 percent – and that the stock will still increase in size,’ Svedäng says. 

In fact, the spawning stock biomass of the central Baltic herring is still far below the EU's Common Fisheries Policy (CFP) target, which is considered sustainable, according to the Baltic Sea Centre's policy officer Charles Berkow. 

‘According to Article 2.2 of the CFP, measures must be taken to bring stocks above levels capable of producing MSY, i.e. above the MSYBtrigger, which is the limit for what is considered a sustainable level of stock spawning biomass. According to ICES forecasts, the central Baltic herring stock is still well below the MSYB trigger,’ says Charles Berkow.

Misreporting increases uncertainty

Herring in the central Baltic Sea is fished in a large-scale mixed fishery where both herring and sprat are caught simultaneously. It has been known for a long time that industrial fisheries sometimes report herring catches as sprat, or vice versa, in order to fulfil their quotas on both stocks. As ICES is dependent on the catch data from commercial fisheries, misreporting can lead to inaccurate forecasts.

‘There are large uncertainties in the forecasts, and this year ICES fears that these uncertainties may be greater than before. They cite misreporting of herring-sprat, but also suspicions that herring or sprat are being reported as flounder. In addition, ICES models do not take into account various environmental consequences, such as herring biodiversity and the impact on different sub-stocks,’ says Charles Berkow.

According to him, this raises the question of how to manage herring stocks. 

‘Much of the increase in the yield forecast for central Baltic herring is based on signs of one unusually strong year class of herring. The management question then becomes: how to deal with this year class? Should you be more cautious and invest in longer-term growth or – as usual – think short-term and fish it up?’ he says.

Sprat on the decline

For some of the other Baltic stocks, ICES advice for 2025 is reasonably in line with previous advice: 

• zero catch for the western spring-spawning herring
• zero catch for the eastern cod stock,  
• 24 tonnes (by-catch quota) for the western cod stock
• around 39,000 tonnes for the Gulf of Riga herring stock.

For the other major Baltic herring stock in the Gulf of Bothnia, ICES is currently unable to advise on TAC-levels. 

For the sprat stock, the ICES assessments show that the spawning stock biomass has declined sharply – and that quotas should be reduced to somewhere between 130,195 tonnes and 169,131 tonnes.

‘It is worrying that sprat has declined so much. According to ICES, there have been three years of poor recruitment, with the last year being very poor. Just like the other large pelagic stocks, sprat is a very important part of the marine ecosystem in the Baltic Sea. The fact that sprat is now declining is a warning that should be taken very seriously,’ says Sara Söderström.
 

Text: Henrik Hamrén