THE fish counter at my local supermarket has a chalkboard displaying how many different species are on sale on any given day. It is usually in the 20s, though sometimes creeps above 30. As well as staples such as cod, salmon and mackerel, it often has trout, sea bass, monkfish, langoustines, tuna, scallops, squid, catfish and flatfish.
The chiller cabinet next door has more: jellied eels and cockles in jars, mussels from Ireland, crab from Indonesia, prawns from Ecuador. In the canned goods section I can also find oysters from South Korea, crab meat from Vietnam, anchovies from the Pacific Ocean, sardines from the north Atlantic Ocean and tuna from the Indian Ocean. The freezers have yet more.
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This abundance makes my head swim. I don’t eat mammal or bird meat, but I do eat seafood, and I want to consume it as ethically and sustainably as possible. But I worry about overfishing and the environmental impacts of salmon farms and shrimp ponds. Most of the products on offer bear a label certifying that they were caught or farmed sustainably, or at least “responsibly”. What does that mean? Who checks? Is it even possible? In other words, can I eat fish with a clear conscience?
Seafood is big business. Every year , about half of it wild-caught and half farmed. To put that in perspective, we eat about . Yet consumption of fish is growing faster than that of meat – around 3.1 per cent a year versus 2.1 per cent. Since 1950, human population . In that same time, the amount of fish we eat has increased by 750 per cent.
This demand is sustained by a fleet of 2.9 million motorised fishing vessels and a vast and growing fish farming industry. are now fished. Despite living on land, humans are a top marine predator.
During recent Brexit negotiations, fishing rights were a major sticking point, despite the fact that this represents a relatively small part of the economy, both in the European Union and the UK. But the importance of the issue underscores the way many feel about an inherent right to the bounty of the sea.
To learn about the impact of our appetite for fish, a good first port of call is a report published every two years by the United Nations’ Food and Agriculture Organization (FAO). Called The State of World Fisheries and Aquaculture (SOFIA), it is a monumental undertaking. As soon as one edition is finished work starts on the next.
Sea half-empty
The picture that the latest report, published last year, paints of the world’s wild marine fisheries . Nearly two-thirds of commercial stocks are classed as sustainable. That “, which is the most fish that can be caught now and in the future without the stock becoming depleted. In other words, the annual catch is equal to the annual increase in biomass through growth and reproduction. The FAO monitors just under 500 fish stocks, which produce about 75 per cent of the global catch. Stocks are , for example north-east Atlantic cod. By this reckoning, at least half – two-thirds of 75 per cent – of fish stocks are sustainable. Let’s call this the “sea half-full” view.
Stocks of the top 10 most-caught marine species, which together account for a third of all the fish caught at sea, are more sustainable than the average. By mass, 78.7 per cent of seafood that ends up on the market comes from stocks the FAO deems sustainable.
This rather upbeat assessment, however, masks a messier situation beneath the waves. “Many countries do not have research ships to go to sea and monitor the stocks,” says Manuel Barange, director of the FAO’s Fisheries and Aquaculture Policy and Resources Division. Even when they do, the science is challenging. It requires an estimate of the total biomass of a species within a huge geographical area, and then an assessment of whether that is enough to support the maximum sustainable yield. The margin for error is so large that a stock is considered sustainable even if it is 20 per cent lower than needed for the maximum sustainable yield.
Even with this wiggle room, the FAO says that about a third of the fish stocks it monitors are overfished, and hence on the road to collapse if nothing is done to stop the plunder. In 1974, when the FAO first started counting, 90 per cent of stocks were sustainable. Today, just 65 per cent are. Even if the level of fishing stays the same, stocks will continue declining. This is the “sea half-empty” view. “We cannot allow this to continue,” said Qu Dongyu, the director general of the FAO, at the launch of the latest SOFIA report.
The failure to stop or even slow the decline in fish stocks has happened in spite of three global commitments to do exactly that. The first was signed by all 193 member states of the FAO in 1995: the . Next came the Aichi Biodiversity Targets (2010) and then the Sustainable Development Goals (2015), which both pledged to end overfishing of wild stocks by 2020 and were adopted by the more than 190 member nations of the UN.
According to Barange, the Code of Conduct was a partial success. It slowed the rate at which stocks were slipping into the “overfished” column. From 1974 to 1995, 20 per cent of stocks flipped from sustainable to unsustainable. In the 25 years since, only another 5 per cent have become unsustainable. “We are flattening the curve,” says Barange. “But not sufficiently.”
The Sustainable Development Goals, however, have had no discernible impact. They are framed explicitly in terms of managing fish stocks: to end overfishing by 2020 and rebuild by 2030. The 2020 target was missed, and the 2030 one is out of reach. Recovery of an overfished stock takes two to three times the species’ life span; an Atlantic cod, which is one of the most overfished species, can live for 25 years, for example. “We are making progress, but it is geographically uneven and not fast enough,” says Barange.
Conflicting definitions
As for the , forget it. , but, to a first approximation, have been completely missed. The specific target for fish set out four aims: end overfishing, put recovery plans in place, eliminate significant negative impacts on threatened species and vulnerable ecosystems, and remain within safe ecological limits. None were met. Some progress has been made on overfishing and recovery plans, but on the other two there has been “no significant change” since the targets were set in 2010.
Even where progress has been made, it is insufficient. Where fish stocks are carefully monitored and assessed and managed with an understanding of how species fit within a broader ecosystem, overfishing has stopped and recovery is under way. But only half of the world’s stocks are managed like this. The other half are in poor shape, battered by unregulated, unreported and illegal fishing.
Hang on, you might think, what about the FAO’s assessment that two-thirds of stocks are sustainable? There is no contradiction, says Barange. FAO and Aichi use different definitions of “stock”. FAO thinks in terms of vast commercial stocks; Aichi in terms of smaller ones defined by ecology. “It depends what units you use,” says Barange.
Another major concern is that sustainable doesn’t necessarily mean environmentally benign. Large-scale commercial fishing, which began in earnest around 1950, can have many negative impacts on the wider ecosystem, such as the accidental catch of non-target species, called by-catch. Most of the fish, seabirds and other unfortunate creatures that are caught by accident are dead or dying by the time they are tossed back into the sea. By-catch has , but it is still considered “unsustainable” by the Convention on Biological Diversity. A .
Lost or discarded fishing equipment is also a problem. According to some estimates, , killing untold numbers of marine animals that get caught up in it.
Certain fishing methods can also take a toll. Bottom trawling, where nets are dragged along the seabed, by undermining the ability of sea-floor microbes to remove harmful sediments.
According to the International Union for Conservation of Nature, which keeps track of the impacts of fisheries on threatened species, fisheries have a net negative impact, and the extinction pressure they create is growing.
Even the concept of sustainability has been questioned. “The word ‘sustainable’ doesn’t mean anything,” says Daniel Pauly at the University of British Columbia in Vancouver. “You can actually overfish sustainably – you can reduce the stock to a tiny fraction of its original abundance and fish the rest sustainably. It’s like cutting an immense forest, but leaving a few trees standing, which you harvest sustainably.” The Canadian cod fishery once yielded 200,000 tonnes a year, for instance. Then industrial fishing quadrupled the catch, collapsing the stock in 1992. It has since recovered somewhat, and now produces around 20,000 tonnes a year – a number that is considered “sustainable”, says Pauly.
“A better question to ask is, how much of the biomass that you had in the water in 1950 is left,” he says. By that measure, nearly all of the world’s fish stocks are profoundly depleted. “If you look at big fish, the biomass has diminished enormously, on the order of 80 to 90 per cent.”
Sustainability also often fails to take into account wider ecological factors. The langoustine fishery in the Firth of Forth in Scotland, for example, is sustainable, but only because so many other species have been fished to extinction and the langoustines no longer have any natural predators, says Pauly.
You also have to consider that fishing vessels are more powerful than they once were, says Pauly. “Even though the biomass has declined, they are able to compensate by finding the few fish that remain, and being able to operate where old trawlers would not be able to,” he says. “The fact that our trawlers maintain catches is not an indication that abundance has remained the same.”
If that wasn’t bad enough, there is also the greenhouse gas emissions of wild fishing operations to consider. According to , per kilocalorie of food produced, wild-caught fish has a bigger global warming footprint than pork, chicken or dairy (see “Carbon costs of food”). Trawler fisheries are the worst, but that is even the case for the lowest-impact wild fisheries. It is because of the huge amount of fuel needed to power long-distance travel over weeks or months, to haul heavy fishing gear, as well as the energy costs of cooling or freezing the fish.
Overall, it is obvious that wild-caught fish come with some hard-to-swallow side orders. “The story of our treatment of the oceans is a shameful one and a very frightening one,” says Tara Garnett at the University of Oxford’s Food Climate Research Network.
Maybe, then, the answer is aquaculture, aka fish farming. This large and rapidly growing sector already supplies 52 per cent of the fish consumed directly by humans, and is projected to increase as demand for seafood rises but the catch from the wild stays essentially flat.
Aquaculture is the fastest-growing sector of global food production. The vast majority happens in Asia, largely for local consumption. Western consumers mostly encounter it in the form of farmed salmon or shrimp. For those consumers striving to make ethical choices, that can spell trouble.
Trouble on the farm
Fish farming has some well-known and undeniable problems, says Grant Stentiford at the in Weymouth, UK. Farmed shrimp, for example, mostly comes from southern and South-East Asia and Ecuador, reared in ponds that were created by destroying mangrove swamps. “There has been a loss of habitat and biodiversity in relation to those industries. I don’t think anyone can really argue about that,” says Stentiford. Add in the environmental cost of feeding the shrimp and freighting them to Western markets, and their calorie-for-calorie carbon footprint can .
Salmon farming, meanwhile, has well-publicised problems with parasites, the overuse of antibiotics, escaped fish breeding with wild ones – potentially diluting the gene pool of wild fish and in some cases leading to sterile offspring – and pollution of the sea floor underneath the pens. Producers are aware of these problems and are trying to clean up their act, says Stentiford, but there is a long way to go.
Aquaculture is also considered in the Aichi targets, which say that by 2020 it should be “managed sustainably, ensuring conservation of biodiversity”. Unsurprisingly, the target wasn’t met. Although most artisanal freshwater aquaculture is sustainable, sea-based aquaculture – called mariculture – isn’t. According to the latest assessment of these targets, it is responsible for “large-scale loss and destruction of coastal wetlands (especially mangroves), and pollution of soil and water”.
Another huge problem with aquaculture is that, paradoxically, it often increases the pressure on wild fisheries. Salmon, tuna, sea bass and many other farmed species are top predators that eat other fish. To meet this demand, around 22 million tonnes of wild fish are caught each year and processed into fish meal. Most of these are sardines, anchovies and other small fry that are edible for humans. To make matters worse, they are mostly caught in the waters of low-income countries, which often have , and then exported to richer countries. “This is completely insane,” says Pauly. In terms of total biomass, to rear certain species requires more wild fish for feed than you ultimately get farmed fish as a result. “Aquaculture is not a producer of fish, it’s a consumer of fish. In part, aquaculture is the reason why fisheries are going down.”
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The most egregious example is tuna farming in the Mediterranean. “Farming of tuna needs 15 to 20 kilograms [of fish meal] per kilo of tuna,” says Pauly. “And when the tuna is fattened it gets a first class ticket to Japan because nobody else can afford it.”
Researchers are working on solutions, but they often involve other environmentally problematic sources of protein such as soy.
As a lover of seafood, but also of nature, I was starting to despair. Thankfully, not all aquaculture is so wasteful. There is a category called “non-fed”, which includes shellfish such as mussels and oysters that feed themselves and create good habitats for other marine life. “Aquaculture is two sectors that are as separate as growing vegetables and ranching cattle,” says Pauly. “The things that don’t need to be fed are a net addition to the seafood available to the world. Or you feed 20 kilos of sardines to a tuna to get 1 kilo of tuna.”
For all this, fed aquaculture can still be more efficient than land-based meat production, says Stentiford. Fish and crustaceans are cold-blooded and aquatic so don’t have to burn energy to heat themselves or to support their own body weight. “There is an inherent efficiency in cold water animals that is not in mammals and birds,” he says. Still, in terms of overall greenhouse gas emissions, most aquaculture is roughly equivalent to the production of pork, chicken and dairy.
“Not all aquaculture is wasteful – shellfish like mussels and oysters feed themselves”
Trawling the aisles
Farmed molluscs aside, buying fish means stepping into a minefield of environmental destruction and social injustice. Yet it is very hard, verging on the impossible, for consumers to make informed choices.
There are several accreditation schemes for wild and farmed fish, but they are far from comprehensive. One of the best known is the Marine Stewardship Council (MSC), which prides itself on its stringent sustainability standards and tracking of supply chains. “It is incredibly complicated to actually know what you are buying,” says the MSC’s chief science officer, Rohan Currey. “That is the whole reason we exist.”
However, just 16 per cent of the world’s wild-caught fish is landed by MSC-certified fleets. The rest may or may not be sustainable, or may not have been assessed by an oversight body. It is impossible to know. And the MSC currently takes no account of greenhouse gas emissions or animal welfare. The overall impact of the MSC divides scientific opinion, with some studies finding that it promotes sustainability, but others that it .
So how can we be confident our seafood choices are sustainable? Even fisheries scientists struggle to know what to buy. “Even as somebody who has a fairly deep interest in this area, I don’t know the answer,” says Stentiford.
Barange also admits that it is hard, and says he just buys whatever is on the market with reasonable confidence that it is sustainable by FAO standards. Pauly passes on the question. “Frankly, I don’t know,” he says. It really ought to be the job of governments, not individuals, to decide what is and what isn’t acceptable, he says.
Until that happens, we are rudderless, trawling the supermarket aisles with no map. But bear in mind that if you do eat fish, there’s almost certainly something fishy about it.
