European seabass

Sea bass is an important species that can be found on many  Dutch menus. In most cases, this is farmed seabass but . wild sea bass is also sold. Unfortunately, there are some problems with both wild and farmed sea bass.

Wild sea bass

The sea bass stock is moving further north due to the warming of the ocean. For years, the stock of this species has been declining but has now become more stable since 2013. .

Nevertheless, the stock is not at all healthy. It takes a very long time for a species to return to safe biological limits. Sea bass is covered by the common fisheries policy but is not managed with a catch quota (indicating which amount of sea bass is allowed to be caught).

Farmed sea bass

Sea bass is also farmed in open cages in the Mediterranean Sea. Unfortunately, there are problems with this form of aquaculture as well, as the used fish feed is unsustainable and the seawater is polluted by chemicals and faeces. There are also risks of escapement which brings farmed sea bass into contact with wild sea bass which may result in physical abnormalities in the wild sea bass population due to genetic differences in the farmed population.

VISwijzer advice

Because of the problems associated with both wild caught and farmed sea bass, it is best to avoid this species. An exception is the sea bass with an ASC ecolabel, which has to comply with many rules. See the extensive VISwijzer for more details.

Why is the seabass coded red on the Fish Guide?

Most of the seabass (96%) we eat is farmed seabass. Unfortunately, there are problems with both wild and farmed seabass. The stock of seabass is moving further and further north because of warming oceanwater. The species was in a very bad state for many years. Since 2013, however, the stock has not declined any further. Nevertheless, the fish stock is not yet healthy. This is because it takes a very long time for a fish species to return to within safe biological limits.

Sea bass is not managed with a catch quota (the amount of sea bass that can be caught). Sea bass is farmed in cages in the Mediterranean. Unfortunately, this is not doing well either. The feed is not sustainable and farming at sea pollutes the water with chemicals and faeces. There is also the risk of farmed seabass mating with its wild counterpart. Because they are genetically different from each other, but farmed seabass being much more genetically homogenous, the wild seabass may lose its genetic diversity and become weaker.

In short, the Fish Guide advice is RED because of the problems with both wild caught seabass and farmed seabass, so it is better to avoid this species. An exception is ASC farmed seabass, where farming has to comply with many rules.

What is the carbon footprint of farmed seabass?

Seabass is a true predator, a species high in the food chain, and therefore needs high quality feed. For farmed fish this often means that feed contains high levels of fish meal and oil to confirm to the dietary needs of the fish. Often these ingredients come from wild sources, this means that fishing vessels are used to harvest fish to make those ingredients. As one can imagine, fishing vessels are reliant on fossil fuels which therefore contributes to Greenhouse Gas Emissions (GHGe). 

In a study, it was determined that seabass in RAS systems have a global warming potential (kg C02 equal to kg of fillet) of 3.6. This was higher than mussel raft systems (2.6), salmon in Norway (1.8) and the UK (3.3). Compared to wild caught finfish the difference is estimated to be even higher, with some farmed finfish, including seabass, showing an ecological footprint 2-15 higher than that of wild caught fish.   

What is the carbon footprint of a seabass fishery?

When looking at the carbon footprint of wild capture fisheries, the main issues to be aware of are fishing techniques and the fuel they use.  

The fishing type that has the highest fuel consumption is bottom trawling. Although bottom trawling is not used to fish seabass directly, seabass is available in beam trawling fisheries as a bycatch species. Beam trawling especially is well known to have a very high fuel consumption as the beam and tickler chains are heavy and have a heavy interaction with the sediment. 

Passive fishing techniques like drift nets, long lines and handlines have a significantly smaller fuel consumption. Therefore, this gear type does not have a very high carbon footprint (but only compared to trawling). 

If consumers want to make a good choice around CO2, they should avoid bottom trawling. 

Are there any social issues concerning seabass farming?

One of the biggest social issues surrounding farmed fish is the provision of fish meal, as fish used for fish meal is not necessarily sustainable and rarely certified. This can be problematic for seabass due to the much higher rate of fish meal needed in their diets compared to others.  

Fish meal is a controversial industry, contributing to overfishing in regions such as Peru. More recently we’ve seen the industry spread to Mauritania, which has since become the stage of a gold-rush to fish for fish meal purposes. This has resulted in more food insecurity for the region, as perfectly edible fish is used completely for fish meal in the factories of Nouadhibou. Instead of only using cuttings, using the whole fish will likely result in hunger for the population of Mauritania, and indeed the whole region, as already 25% of the people struggle with securing food.  

There exists a high chance that uncertified farmed seabass is fed with this unethical fish meal from Mauritania. The only way to make sure the fish on your plate did not contribute to this practise, is to buy ASC or organic seabass, which is farmed with responsibly sourced feeds.   

What certification exists in relation to farmed seabass?

As seabass is a popular farmed fish, ASC certification exists for this species and can be searched for in supermarkets. ASC ensures that seabass with their label has a reduced negative impact to biodiversity compared to non-ASC labelled farmed seabass and has the backing of a proper traceability procedure to back up this claim. Good Fish supports this label as a sustainable choice. 

Another certification for seabass is GLOBAL GAP. It covers the whole supply chain including processing plants. Good Fish considers GLOBAL GAP the minimum requirement for farmed fish to gain access to Dutch supermarkets.  

Best Aquaculture Practices (BAP) is an American counterpart to ASC, created by the Global Seafood Alliance. They too cover the whole supply chain including processing plants, but ASC still beats them when it comes to traceability.  

In the supermarket you may also find seabass with a Friend of the Sea (FOS) ecolabel. Although improvements have been made to the reliability of the label, it is still not transparent enough compared to other trusted labels. Therefore, FOS is not supported by either the World Wildlife Fund or Good Fish as a reliable quality mark.  

Lastly organic seabass can be found in the supermarkets. Organically farmed fish stands for a lower maximum of fish in the pens compared to conventional practices, unenriched water, no preventive medicines or growth hormones used and natural reproduction. The certification of these aspects comes under the Dutch or European EKO Quality mark. 

In short: If you want to be certain that your seabass is sustainable, choose an ASC or organic seabass.

What about the welfare of seabass?

Currently, the vast majority of seabass are killed using the inhumane method of live chilling in ice slurry or are left to asphyxiate on land. These methods are aversive, causing suffering for extended periods (minutes to hours) before consciousness is lost and is deemed an unacceptable slaughter method. Contrary to salmon and trout, the electronic stunning is not common practice, even for organic seabass. 

Issues with farming

The majority of European seabass aquaculture is carried out at sea. However, an increasing number are farmed on land in tanks with recirculation systems. Seacage farming uses nets in open water where the natural exchange of water can remove excess nutrients. A common disadvantage of this system is the effect it has on the water around the cages. Due to the amount of nutrients that enter the water through the fish feed, local eutrophication is common. This sometimes even results in oxygen-deficient zones under the nets.

Seabass farming poses a whole range of other problems as well. These include escapes, degraded water quality, the use of wild fish as feed and the negative impact on biodiversity. There are also ethical issues related to animal welfare and the origin of fishmeal as discussed earlier.

A problem not yet discussed is disease. As sea bass farming is often a form of intensive aquaculture, disease is a common problem that needs to be addressed. The main disease affecting European sea bass is Viral Nerve Necrosis (VNN). However, there is no vaccine or drug that can be given to farmed seabass to control this. Other diseases include Vibriosis and Tenacibaculosis, as well as parasite infestations.

How much is seabass farmed?

Farmed sea bass has increased exponentially since the early 1980s. Since 1992, farmed European sea bass has overtaken wild catch: 96% of the sea bass consumed comes from farmed/aquaculture, due to increased demand and the decline of wild fish stocks. In 2016, the production of farmed sea bass internationally reached 191,000 tonnes. Globally, Turkey is by far the largest producer of farmed sea bass. In the EU, Greece, Spain, Croatia and Italy are the largest producers of sea bass, meaning that the Mediterranean region accounts for 94% of Europe’s farmed sea bass production.

Are there antibiotics used in seabass aquaculture?

Due of the wide variety of diseases that affect seabass, antibiotics are used widely as treatment. However, within the EU, it is common practice not to immediately use antibiotics to treat disease.  Through EU regulation, “Effective biosecurity and health plans”  must first be considered in the management of pathogens and diseases. This is done through effective legislation and management.  

Legislation on the controlled used of antibiotics is tightly regulated in the European Union. However, seabass is also farmed by countries outside the EU, such as Turkey, the world’s largest producer of farmed seabass. As a non-EU state they do not have to follow such regulations. Because Turkey is such a large supplier seabass to the Netherlands, it might be the case that the seabass available here in the Netherlands has been treated with antibiotics.  

What fishing techniques are used to harvest wild caught Seabass?

When seabass is wild caught in the (Greater) North Sea, longlines, bottom trawlers, fixed/drift nets, Danish seines and pelagic trawlers are used (Table, 1). According to ICES, 45% of commercial landings of European Seabass is done by lines, this includes handlines and pole lines.  

Tabel 1: Seabass catch methods (ICES, 2021a)
What season is this fish available?

Wild caught seabass is best when the spawning period is over. This is typically from January to March then July to December. This is because the quality of the meat is better. Despite this, Good Fish believes that although consuming fish outside the spawning season is important for the quality of the meat, it has no significant effect on the health of the stock. Therefore, seabass bought in the right season is not automatically a sustainable fish. With farmed, there is no defined season when it is best to buy them. 

How do fishingmethods affect the ecosystem?

Out of the three main fishing methods for seabass, handlines is the most sustainable. This is because they are highly selective and do not damage the seafloor. 

Fixed/drift nets are “passive” nets and can be used to trap fish. This means they are not dragged or towed by fishing vessels. These fishing techniques are therefore normally not associated with seafloor destruction. However, the nets can be abandoned or lost leading to ghost gear where it can continue to catch fish unintentionally. Besides, passive methods tend to occasionally have bycatch of marine mammals, seabirds, sharks or turtles, depending on the region of catch. This is most significant in the Bay of Biscay.   

When bottom trawling a net is dragged along the seafloor to catch bottom dwelling species. Because these species are non-shoaling species and are occurring amongst many others, bottom trawling is a mixed fishery with often high bycatch rates. Bottom trawling can be extremely damaging to the seafloor ecosystem. When comparing the three main fishing methods for seabass, trawling is the least sustainable.  

Are there any social issues concerning seabass wild catch?

On average, other than lobster, seabass fetches the highest prices of species from the North-East Atlantic. The expensive prices that seabass sell for are contributing to illegal fishing as will be discussed in the following sections.  

Recreational Fisheries 

The public have a direct role to play in seabass declines other than purchasing seabass. Besides being an important commercial species, they are also a prized recreational species. However recreational anglers are legally limited to catch and take two seabass individual per day. This includes a minimum size of 42 cm. In the case of seabass recreational removals are treated as a separate fleet in stock assessments. 

Figure 1: Origin of catches in the Greater North Sea (ICES, 2021a)

Illegal Fishing 

There is a significant issue with illegal seabass fishing where some recreational anglers are using unfair and detrimental fishing gear. In areas especially surrounding the Europoort in Rotterdam and the Maasvlakte the water is unusually warm, encouraging seabass to congregate. Here, seabass gather in large numbers and are being caught illegally by poachers. Legal anglers have witnessed these poachers using illegal catch methods such as lead lines with barbs. The police in these areas are aware of this problem and recognise that most anglers are law abiding and are at a disadvantage when illegal poaching occurs. 

Although it can’t be verified, it seems as though the illegal poachers are using their catch of seabass to sell as part of their livelihoods as they catch up to 10 kilograms a day. Often, these illegal catches are sold into the catering industry where the poachers risk a fine of 1500 euros. From research done by Good Fish in 2018, this very much seems to the be the case. Interviews with suppliers showed that they were offered seabass of up to 50kg by anglers who had spent long periods at sea on a regular basis. This illegal trade means a loss of control on matters such as hygiene and labelling (research done by Good Fish in 2018). 

The Seaport police seize hundreds of kilos of seabass a year and the issue does not seem to be abating. The Public Prosecution Service is involved since seabass are heavily threatened and the seaport police continue to actively hut these poachers.  

Another reason why this is a social issue as well an ecological one is that the illegal poachers are often considerably intimidating to law abiding fishermen. There have been instances of physical force being used against them and a culture of intimidation has been created.  

How is seabass managed in Europe?

European seabass is managed under the Common Fisheries Policy although this is only partially effective for this species. There is no shared management plan with the UK on this stock. There are 5 different stocks in the Northeast Atlantic to make management and providing advice from ICES more specific.  

There is no quota for seabass but ICES does give advice on the maximum catch and minimum conservation references sizes (MSR) for individuals have been in place since 1983. Because seabass is not a TAC species, the landing obligation does not apply.  

The management measures put in place in 2015 meant that less seabass was caught (Figure 1) which saw a predicted increase in biomass in 2020. There is a current multiannual management plan (MAP) for this stocks in western waters, which is considered to be positive since it is a precautionary approach. The stock assessments could be improved by more data on recreational removal data and data on discarded seabass in commercial fisheries, which are now scarce.  


The Mediterranean does not fall under the European common fisheries policy but are managed on national level. Unfortunately this has led to lack of effective management.  

How is European Seabass’ stock doing?

Northern waters 

The sea bass stock in the southern and central North Sea, Irish Sea, The Channel, Bristol Channel and the Celtic Sea has grown just above the limit level but is still below the level recommended under the precautionary approach. Although fishing pressure has declined substantially since 2013 and has been well below MSY for several years, this results in only limited growth in the stock. Recruitment has been low since 2008, which is likely the reason for the lagging growth.  

Figure 2: Spawning stock biomass (up) and Fishing mortality including recreational removal (below) in the greater North Sea region (ICES, 2021a).

Northern and Central Bay of Biscay 

In the South-western waters of the Atlantic, seabass is in better shape. SSB is not only above limit level but just above the set precautionary level as well. Fishing mortality is well below both MSY and precautionary level as well. However, seabass is in a precarious position and lifting these measures could shift the stocks of seabass into dangerous levels again. Furthermore, the emergency measures didn’t concern the Mediterranean Sea where stocks were suffering, making the management of depleting seabass ineffective across seabass’s range.  

Figure 3: Spawning stock biomass (up) and Fishing mortality including recreational removal (below) in the Bay of Biscay (ICES, 2021a).


In the Mediterranean, the stock is estimated to have declined by 20-30% since the 1990’s. European seabass saw significant depletion since the increase in seabass fisheries in the 20th century and fluctuations then on (Figure 7). This resulted in a 32% decrease of Seabass stock size across their European range.    

In the Mediterranean, fish stocks are managed at national level which continues to result in overfishing. This means that the abundance of seabass continues to be low due to overfishing and the increasing climatic pressures of global warming.  


ICES maintains that the European stock of seabass remains in a fragile state and only growing very slowly. It was advised by CEFAS that it could take 15 years for the stock to increase fully. In their worst state, European seabass stocks were looking likely to crash in the near future if emergency measures were not adopted. However, a genuine threat of extinction has only been claimed in the media and is not substantiated by data.  

Can I eat Seabass?

In the Good Fish VISwijzer, European seabass is coded red. This is for all catch methods, demersal otter trawl, Midwater otter trawl, Trawls, Set longlines, Handlines and pole-lines (hand operated), Gillnets in the Northeast Atlantic and the Mediterranean. The red code also applies to farmed seabass in the Mediterranean using nets pens and cages.  

Although the effect on the ecosystem using handlines and pole lines is coded green, the fish stocks, fishing pressure and fishery management all score red. However, the stocks of seabass are not managed fully as it continues to not be a TAC species with no quota limitations. This is why the overall score is red. The other fishing methods score poorly for their ecosystem effects since they have a significant amount of associated bycatch. The uncertified nets and pens farming in the Mediterranean also scored red due to excess nutrients from farms leaching into the marine environment. Diseases are also a common issue in seabass farming, as well as escapees and the ingredients in feed.  

The places where European seabass is not coded red is when it has come from a farm that has been certified by the ASC. Furthermore, the seabass from farms in the Mediterranean that have Global GAP certification are colour coded yellow. The yellow code is due to the lack of research on the effect this type of certification has on the environment.  

CEFAS advised that it could take up to 15 years for European seabass to reach safe levels again. Therefore, it is possible if management measures continue to be precautionary, in the next two decades, seabass will be more sustainable to consume. It is not advisable for consumers to purchase any wild caught seabass as it is deemed as unsustainable and harmful to the stock and the environment.  

Why isn’t seabass MSC certified?

The MSC main criteria for certification are a healthy stock, good management and low impact on other species and the ecosystem. Therefore, because European seabass is not a TAC species with defined quotas, the management of the species is not good enough for MSC certification although the EU has introduced some management measures. Interestingly however, the MSC claims that European seabass has both clear management and “sound” management. Despite this, there continues to be little accurate information on the stock of seabass and high levels of bycatch which are reasons for the lack of MSC certification. 

In 2013, the MSC certified the Association of Professional Handline Fishermen (VHBL) in the Netherlands. This was for a rod and line seabass fishery. This fishery was audited in 2014 based on the seabass stock status changing. The conclusion was that numerous performance indicators were below what they should have been. This indicated that the MSC certification should be suspended. Since 2015, the VHBL have not got this certification anymore.