Cod. Photo: Stefan Beskow /Azote.

Targeted fishing of Eastern Baltic cod has been prohibited since July this year, and will remain heavily restricted during all of next year. But even with no fishing the stock is not expected to recover in at least five years. Unless something else is done.

Scrapping subsidies from EMMF

This will hurt fishers and local communities. Therefore, the European Commission (EC) proposes a reintroduction of subsidies for scrapping fishing vessels – with financial support from the European Maritime and Fisheries Fund (EMFF). This will not involve new funding, but allow Member States to redirect funds already appropriated.

Reducing the number of cod-fishing vessels will create a better balance between fishing capacity and available fishing opportunities, the EC argues, and permanently reduce fishing pressure. Data and control need to be improved, and the Commission also has proposals for more observers on board and for more monitoring of fishing vessels.

EC's arguments might hurt cod recovery

For the distressed eastern Baltic cod stock, less fishing pressure is good news. But from a scientific standpoint, the arguments EC uses to sell this new proposal are problematic – and might have negative consequences for the overall strategy for the recovery of the eastern Baltic cod in the coming years.

The EC refers only to new scientific assessments indicating that environmental conditions – primarily oxygen depletion (hypoxia) – have a much more important impact on the eastern Baltic cod than previously estimated. In view of the recent scientific knowledge provided by ICES and others, that description is too one-sided. Besides environmental conditions such as hypoxia there are several other – and crucial – factors related to the current cod crisis.

A broader view

It is now generally accepted that the eastern Baltic cod is in a dire situation. There is less agreement on what has caused it. The lack of scientific consensus stems from the fact that there are currently a number of different plausible theories at hand.

Compared to what is mentioned in the EC proposal, scientists at ICES, for instance, present a somewhat broader picture. In ICES advice for the eastern cod, they point out that the poor status of the Eastern Baltic cod “is largely driven by biological changes in the stock during the last decades.”

They also write that the low growth, poor condition, and high natural mortality of cod are related to changes in the ecosystem, which include “poor oxygen conditions, low availability of fish prey in the main distribution area of cod and high levels of parasite infestations”. The EC proposal only mentions the first of the above.

"ICES does not give the primacy to oxygen depletion"

Crucially, ICES also writes that “the relative effect on the cod stock is unclear”. That is, ICES does not give the primacy to oxygen depletion that the Commission does. In a background document, scientists in an ICES expert group also mention a fourth contributing factor: "reduced size at maturation".

Further, ICES notes in its advice for the cod that “these drivers are interrelated”. For example, the low availability of fish prey (i.e. lack of food) may inhibit cod condition, which in turn might make the cod more susceptible to parasite infections.

Several possible reasons for cod decline

Other research has documented the decline in the cod condition during the past decade. Possible explanations for this decline include:

• low availability of fish prey in the main distribution area of cod
• shortage of benthic prey given the stagnation period and frequent oxygen depletion at the bottom
• increased extent of low oxygen areas that could affect cod growth directly via altering metabolism and reducing food intake
• increased infestation with parasites
• size selectivity in commercial fisheries, which may have contributed to a larger proportion of smaller fish in the stock that may have led to density-dependent effects.

Finding the prey

Since sprat and herring are the main forage fish for cod – and taking into consideration the fact that the cods’ poor condition and growth is most problably connected to lack of food (starvation) – ICES places quite a lot of emphasis on discussing the relationship between the cod and its prey.

In the advice for sprat, ICES recommends that “a spatial management plan is considered for the fisheries that catch sprat, with the aim to improve the condition of cod stocks”.

At present, the high biomass of the Baltic sprat and herring stocks is to large extent distributed further north in the Baltic Sea, outside the distribution area for cod.

ICES concludes that “any fishery on the two prey species in the main cod distribution area (subdivisions 25–26) will potentially decrease the local sprat density, which may lead to increased food deprivation for cod”, and continues:  

“The relative catch proportion of sprat in the main cod distribution area has since 2010 increased from 37% of the total catch to 56% in 2012–2018. Thus restrictions established on sprat fisheries in the main cod distribution area would result in increased availability of clupeid prey, which could benefit the cod stock; however, several other factors also have impact on the cod stock”.

The EC proposal to reintroduce subsidies for scrapping fishing vessels in the Baltic is an amendment of the exiting multiannual plan for management of the cod, herring and sprat (regulation 2016/1139).

"Safeguard measures are to be taken"

In its proposal, the Commission notes that the Baltic multiannual plan (MAP) sets out that, “when scientific advice indicates that a stock is under threat, safeguard measures are to be taken.” This includes the reduction of fishing opportunities and specific conservation measures. The MAP also states that “those measures should be supplemented by all other appropriate measures”.

Reduce fishing on cod's main prey fish

In the case of the eastern Baltic cod, there is room for other supplementary “appropriate measures”, besides the scrapping of fishing vessels. Since the eastern Baltic cod is probably starving, one such measure could be to reduce the fishing pressure on cod’s main prey fish, herring and sprat, in the southern Baltic Sea where the main Baltic cod stock is located. Spatial management of pelagic fisheries in the Baltic should also ensure that they do not impact negatively on food availability for the relatively healthy cod population reported from the Åland Sea.

Although oxygen levels are important, it will in all probability take a long time for measures to improve them to have a significant impact on the Baltic sea environment. Food deprivation can, on the other hand, be reduced relatively quickly. Improving food availability for the cod could make the recovery quicker. Together with the Commission’s proposals for capacity reduction, data collection and control, it would give a better chance for recovery than what is on the table now.

By connecting the current cod crisis solely to factors outside fisheries (oxygen depletion), EC misses out on this opportunity. It remains to be seen if this will be rectified by the European Parliament and the Council when they consider the Commission proposal.