Has Seaspiracy put you off farmed salmon? Here’s the best fish to eat instead

A new Netflix documentary has made fresh claims for the damage caused by fish farming. But given that many wild stocks are also endangered, what can we eat?

Around half of the fish we eat is farmed, compared to five per cent in 1970

Harry Wallop

Wednesday March 31 2021, 5.00pm, The Times

Every month another recipe box subscription service pops up, be it for vegans, pasta fans or those who want to cook only mung beans on Thursdays. One of the newest is Zested, which promises to deliver sustainable meals to consumers’ homes. Not just the packaging, but the ingredients too. Its recipe card for a (rather delicious) trout dish contains a bold explanation for the choice of fish: “The salmon industry is an environmental disaster.”

Wil Hopson, the co-founder of Zested, rattles off the reasons for his opposition to farmed salmon: its use of antibiotics; pollution; the number of wild fish caught to feed the farmed ones; salmon that escape and breed with wild ones, creating “mutant fish”; and the high proportion of fish that die while being farmed. “I’d say one of the most impactful things you can do as a consumer is cut salmon out of your diet. There are so many areas of sustainability that are nuanced, but for me that is so black and white.”

Is it really that black and white? Can farmed fish ever be sustainable? Certainly not, according to Seaspiracy, a documentary that has just landed on Netflix. It’s a 90-minute polemic against the oceans being overfished, but is also against farmed salmon, which it claims are “swimming in circles in their own filth”.


The documentary, filmed and presented by Ali Tabrizi, has raised the hackles of the fishing industry, which claims it is riddled with inaccuracies. However, it has once again shone a spotlight on aquaculture, a form of food production that divides experts like almost no other.

Industrial fish farming is a relatively new phenomenon. In 1970, a mere 5 per cent of the fish the world ate was farmed; now it is about 50 per cent. It is only likely to get bigger. And taller. Last month, Singapore announced that an eight-storey fish farm was soon going to open in the city, with the aim of providing 3,000 tonnes of fish each year to feed the city.

For every person who is opposed to farmed fish, there is another who believes it’s the future. Robin Hancock is the co-founder of Wright Brothers, an upmarket fishmonger. “Based on population projections, to feed the world we need farmed fish. Not only is sustainable fish farming doable, it has to be doable,” he says.

Dawn Purchase, the aquaculture programme manager at the Marine Conservation Society (MCS), a non-profit organisation that campaigns for better oceans, explains why so many people are uncomfortable with salmon farming in particular. “When salmon farming started, it had a very bad reputation and that bad reputation was very well deserved. It had a lot of environmental impacts, it was very poorly regulated, used a lot of antibiotics, feed and chemicals, and had a lot of escapes.”

Because it is done in large pens in open water, any pollution caused by fish faeces or dead fish leaks into the loch or the sea, contaminating the local environment. Sea lice are a particular problem. These parasites attack the salmon’s head and neck, and if enough latch on they will kill it.

The Scottish Salmon Producers Organisation says that sea lice levels, which it monitors closely, have fallen for the past three years, but some campaigners would argue that the improvements have been too modest. One, Corin Smith, has calculated that caged salmon deaths rose from 4,421 tonnes in 2002 to 25,772 tonnes in 2019. “The volume of salmon dying prematurely on salmon farms in Scotland is now biblical in scale,” he has said. Two years ago, the Scottish parliament published a report into the salmon farming industry that stated: “The status quo is not an option.”

Campaigners also point out that salmon is a relatively inefficient form of protein to farm. Lambs may belch out large quantities of methane, causing global warming, but they eat grass, a readily available food source. Salmon eat pellets made partially out of wild fish. “Globally, to feed the fish industry they are catching 450 billion tons of fish every year,” says Hopson.

The salmon industry has made progress in ensuring the pellets are made increasingly from vegetable oils and vegetable proteins and that when it comes to feed conversion ratio — the amount of food you have to give to an animal to produce 1kg of meat — salmon is much more efficient than beef, lamb or poultry. However, if you like salmon — and the average British household has gone from consuming 2g a week in the 1970s to 15g a week in 2019 — how do you ensure it comes from a good, sustainable fish farm?

Hancock says you can get fantastic quality farmed salmon as long as you know what you’re looking for. “You can tell from the fat stripes if it’s been agile.” White stripes might look appealing, but it means that the fish probably sat in an over-crowded pen, not moving, but just being fattened up.

Many believe the tastiest salmon are wild. However, a lot of wild salmon is endangered, especially Atlantic salmon, which is considered to be overfished. This is partly why farmed Atlantic salmon has gained in popularity so much. In theory, it should be the conservationist’s option. Wild sockeye salmon, sometimes called red salmon, however, is considered a safe bet. There are decent supplies of Alaskan sockeye and it is available in many supermarkets.

In the same way that the Marine Stewardship Council has its distinctive blue tick showing which wild fish are fine to eat, the Aquaculture Stewardship Council has a white tick for farmed fish. It certifies some farmed seabass and sea bream, for instance. Seabass and sea bream, both of which are invariably farmed in Greece or Turkey, suffer from many of the same problems that some Scottish salmon does. Both are farmed in open net pens and both are usually often fed on pellets that have been derived from wild-caught fish.

The Marine Conservation Society Good Fish Guide points out: “Seabass are carnivorous fish that require more fish in their diet than farming them actually produces, leading to a net loss of marine proteins and oils.”

The ASC-certified seabass should, however, be fed by suppliers “that have a responsible feed sourcing policy”. Although it’s difficult to verify this, as Hancock at Wright Brothers says, if you are eating farmed seabass, “you are giving the wild populations a chance to recover”.

The MCS’s Good Fish Guide gives every single fish a one to five traffic light sustainability rating. There’s also an app you can consult, and some salmon does merit the highest score. Purchase also suggests that people concerned about the environmental impact should opt for organic fish. “Organically produced fish tends to have a lower environmental impact. One of the main reasons is that organic uses by-products and trimmings from human consumption fisheries to make its feed so it doesn’t rely on any primary wild caught fish.”

However, the best thing consumers can do is consider alternative fish breeds, she says. “Pangasius is good; we just put pangasius on our ‘fish to eat’ list.” This is often called basa or Vietnamese river cobbler and, unlike salmon, is happy being fed seaweed rather than high-protein pellets. A white fish, it is often found in the freezer cabinets of supermarkets. “If you want a treat, you could go for farmed Atlantic halibut in Scotland.”

Halibut in the wild is considered endangered, but is farmed on land on the isle of Gigha, off the west coast of Scotland, where the water is pumped into huge tanks and cleaned before being released back into the sea.

“The problem with industrial salmon farming isn’t any single farm — it is the scale,” says Ruth Westcott at Sustainable Fish Cities, a campaign group for sustainable fish. “Farmed trout is really good because it tends to be well managed and at a scale that can coexist with its environment.”

Many restaurants and fishmongers recommend ChalkStream, which processes farmed trout in Hampshire. “All farming has an impact, it’s how you reduce it,” says ChalkStream co-founder Arthur Voelcker, who says the mortality rate on his farms is just 1 per cent (at the worst salmon farms it can be over 20 per cent).

ChalkStream uses something called a flow-through system. “The water comes through from the chalk streams, it comes through the farms, and we can settle it” — the process of letting any waste matter or pollution fall to the bottom — “before it goes back into the river. It’s very enclosed and very controlled.”

Voelcker is nervous about criticising his peers in the Scottish salmon industry, though, pointing out that the best ones are a world away from the “battery chicken farms of the sea” reputation that has been painted by some campaigners.

His nervousness about being seen as a posterboy for good practice is possibly because earlier this year one of his own suppliers was filmed throwing live fish and kicking them on the ground. He says: “We’ve now done a thorough investigation of all our supplier farms, and worked really hard with them to ensure they are compliant,” adding that the farm in question “has taken action” to ensure it will never happen again.

When even a company lauded by Jamie Oliver and many top restaurants finds itself finds itself dealing with welfare problems, it just shows what a minefield it is for consumers. How can they ever be certain that the fish they eat is really sustainable?



A guide to the fish for your dish

Fish to avoid

Sea bream caught at sea
It is believed stocks of sea bream, especially off the Bay of Biscay, are very low. Many dolphins die, caught by dredging nets, as a result of sea bream fishing.

Halibut caught at sea
The full status of halibut stocks is unknown, but it is classified as endangered globally.

Atlantic salmon caught at sea
Stocks of Atlantic salmon caught off the west coast of Scotland are low and should be avoided.

Bluefin tuna caught at sea
One of the most overfished of all species. Stock levels have recovered a bit in recent years, but are still at critically low levels.


Sometimes OK to eat

Sea bass line caught at sea
Sea bass used to be overfished, but stock levels are improving and if it is caught off the coast of Cornwall in the traditional method — using lines rather than nets — it is a pretty good option. Avoid trawled bass from the Bay of Biscay.

Atlantic cod caught at sea
A lot of cod around the UK is depleted and, as a general rule, you should avoid it. However, there are quite a few fishermen certified as sustainable by the Marine Stewardship Council (MSC) with a blue tick. These are OK to eat. Far better is Pacific cod, where there are good supplies.

Haddock caught at sea
There are pretty good supplies of haddock, but stock levels do vary, depending on how cold the winter has been (the colder, the better). However, always avoid eating undersized fish (below 30cm) and during their main breeding season in March and April.

Alaskan sockeye (or red) salmon caught at sea
Unlike Atlantic salmon, stocks of its cousin the sockeye salmon are in far better health. They mostly come from Alaska.

Farmed Atlantic salmon
There is good farmed Scottish salmon and bad farmed Scottish salmon. It depends on who is doing the farming and whether they are looking after the environment, keeping a check on sea lice levels and ensuring the salmon are fed sustainable feed.

Albacore tuna pole-caught
Stocks of albacore tuna are far higher than bluefin, especially if they come from the north Atlantic and are pole-caught. These are often MSC-certified.


Best fish to eat

UK farmed trout
Trout tend to be farmed in a pretty sustainable way, with little environmental impact on UK rivers.

Pangasius or Vietnamese river cobbler (farmed)
They are happy to eat vegetable protein so wild fish are not being caught to feed them. They invariably arrive in the UK frozen from Thailand or Vietnam via boat.

Hake caught at sea
Hake used to be overfished, but stocks off Cornwall are in a good state now. Plus, Cornish fishermen who are MSC-certified tend to use pingers that scare dolphins away from the nets.



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