Why you shouldn’t eat farmed fish – a graphical explanation

Do you know where your fish comes from? Well, yeah, it comes from the water, but there’s a little more to it than that. Nigel Upchurch, who previously explained the benefits of turning off your computer at night, describes in this short one-minute video why eating farmed fish isn’t the best idea. In short, while farming fish seems like a good solution to depleted wild supply, the process actually ends up using even more natural resources.

I like Nigel’s understated approach. Not too flashy that it makes you dizzy, but engaging enough to get you looking. The video is light on data, but that works well for a public service announcement.

Does this mean we should slow down fish eating altogether, or just farmed fish?

[Video link | Thanks, Nigel]


  • DojoMouse May 27, 2011 at 2:31 am

    Every stage you go through the food chain typically involves an efficiency loss of around factor 5 – 10. Here it’s factor 5.

    So eating vegetables is best. Eating animals that eat vegetables is significantly worse under most farming practices… though there are very few exceptions that would allow “ethical” consumption of relatively small amounts of animal protein (such as a sheep eating the grass on a hill that you wouldn’t otherwise be able to grow crops on – this is independent of any issues you might have about eating sheep).

    Eating animals that eat animals (carnivores) is far worse again. They’re part of the foodchain, so in that sense fair enough to eat them in extreme moderation (the ocean needs salmon to maintain a healthy balance of population, we can eat salmon, fair enough) but massively depleting the stocks of ocean fish in order to feed factory fish is king-kong-stupid.

    There are plenty of viable farmed fish options that eat vegetables (putting them a long step up from salmon) and additionally are cold blooded, making them an extremely energy and resource efficient source of protein. They can additionally be linked in with agricultural systems in a pretty efficient way. If you’re going to eat farmed fish, eat farmed herbivorous fish… it’s better than most other protein options.

    • DojoMouse is right – “fish” is too broad a term. The key is that this is true of “meat-eating fish.” (Alton Brown did a terrific segment on farmed salmon, where the punchline is basically “this is why we do not farm lions.”)

      There are also ecological issues around some fish farms (open-water pens where waste and potential disease isn’t managed well). On the other hand, farmed shellfish actually clean the water they live in. But that’s a different visualization…

      The Monterey Bay Aquarium Seafood Watch site is the place to go to really learn to think about sustainability species-by-species – http://www.montereybayaquarium.org/cr/seafoodwatch.aspx

  • This does beg a rather obvious question: how many offspring does each farmed fish produce, and what percentage of those offspring survive in the predator-free farm environment versus the wild ocean? If each fish has at least 5 offspring before the parent is harvested for food and all of the children survive, it’s a net zero effect. If they have more offspring than 5, which I suspect, then this practice actually increases the total fish population.

  • Gong-Yi Liao May 27, 2011 at 5:32 am

    Go vegetarian.

  • All this tells me is how much fish it takes to produce farmed salmon. It leaves me with no idea as to whether a wild salmon has consumed more or less fish (or other resources) before it gets to someone’s plate.

    If it is possible to catch anchovies & process them into Salmon food, using less than a fifth of the energy that it takes to catch the same weight of wild salmon, then farmed salmon might be better than wild salmon.

    If a wild salmon consumes 20x its weight in fish, prior to being eaten by a human, then farmed salmon might be better than wild salmon.

    If both are true, then farmed salmon is almost certainly better than wild salmon.

    Personally I never touch the stuff, so it won’t influence me either way, but IMHO, these missing data degrade the message by being left out.

  • Why not have one farm of carnivore fish and another farm of vegetarian fish where plants are also grown. Feed the vegetarian fish to the carnivore fish – surely that would solve a lot of the problem.

    Also the real problem isn’t ethical eating issues. There’s too many people and the population growth needs to be curbed through limiting the number of children parents are allowed to have. Of course this is too much of a political hot potato and so people will skirt around the issue.

    • colourlessgreen May 27, 2011 at 9:02 am

      Adam’s right. The elephant in the room is that human population keeps growing. And unless that stops, we’re simply going to run out of food. The question is: at what trajectory?

      If we eat carnivores, well, then it will be faster. But what I get from this is that salmon are simply a poor choice of fish to eat. I thought salmon get their pink colour from eating shrimp and things like that (wiki answers agrees that salmon eat smaller fish, squid, etc. http://wiki.answers.com/Q/What_do_salmon_eat). I live in a salmon-rich area (the Pacific NW of the US), but I do try to limit how much salmon I eat because it is a carnivore.

      Eating meat is energy intensive enough. Eating meat that eats meat is an order of magnitude worse.

      All in all, farming in general is a necessary evil. From fossil fuel-produced fertilisers and pesticides, to runoff issues to transportation to meat production–the human world is constantly at odds with its environment. We take, extract, and mold everything we can. We’re far beyond our carrying capacity, and that is the real issue.

      So, eat less meat, have fewer children. Sacrifice a little bit so that everyone can have a bit of their share. Be good to one another. Even people you don’t know.

      • I recently went to the Monterey Bay Aquarium and they had a useful Seafood Watch pocket guide:


        They have best choices, good alternatives, and fish to avoid (one of them being farmed salmon).

      • It is interesting- growth in population has improved living standards, average life span, etc- basic economics. We are not over populated. If you took evey human alive, they would fit into the state of texas – each with a 2000 SF house! Do the math. Do any of you people actually research what you put out there? SQ of texas divided by human population……

    • Wow Adam- limiting the number of children we are allowed to have? What’s next for us in your uptopian dream of a future? Why not just kill old people? I mean based on your logic, anything goes to save the world- if it needs saving. If you are so concerend about the population- self selct out and show your commitment to save the world. If you are in need of a plastic bag to put over your head, let me know- I am all for focused population control.

  • Posted on behalf of Ruth Salmon:

    As Nigel’s video correctly points out, many of the world’s fisheries are being unsustainably depleted. Aquaculture – the farming of finfish, shellfish and even sea plants – is increasingly making up the shortfall.

    In the case of farmed salmon, it’s true that a portion of fish feed includes smaller wild fish, such as anchovies and sardines. However, the reduction fisheries that supply fish meal and oil to the Canadian aquaculture industry are sustainably managed. Canadian feed manufacturers are developing new feeds that are replacing some of the fish-based ingredients with those from alternate sources, such as vegetables – yet still provide high quality, nutritious farmed salmon with no significant reduction in the amount of heart-healthy omega-3 fatty acids in the fish. Canadian salmon farmers use less than 30 percent fish meal and oil in their feed. That means only 0.5 kg of wild fish meal and oil are needed to grow 1 kg of farmed salmon. Where possible, the alternative feed ingredients are sourced locally. As global salmon farming has grown from zero to 1.3 million tons produced, the volume of fishmeal produced has stayed the same since the 1970s.

    It’s also important to note that fish convert feed to body mass much more efficiently than land-based animals, such as cows, pigs and chickens.

    Farmed salmon is a nutritious, delicious product that takes pressure off our oceans, and is available fresh, year-round.

    More information on salmon and feed is here: http://www.aquaculture.ca/files/species-salmon.php

    Ruth Salmon
    Executive Director
    Canadian Aquaculture Industry Alliance

  • I don’t even like fish besides the occasional sake nigiri, but I don’t think reducing consumption at the individual level is likely to provide any measurable benefit. After all, more people are born every second, how can you convince everyone to slow down at a rate better or equal to the rate of births/deaths. It would be smarter to come up with a solution that allowed us to fish as much as we need until the limit of sustaining the species’ we are catching.

    From there, the price of fish will control how much people eat, as it becomes more expensive, you will eat less.

  • Beautiful example of storytelling with data. Thanks for sharing!

  • gregorylent May 31, 2011 at 2:07 am

    all fish, bye-bye

  • The message is simple: “it takes 5 wild fish to produce one farmed fish”. So eating farmed fish is not all what it’s cracked out to be. Or is it?

  • this is completly wrong. our company feeds its salmon with feed ( a major international brand) containing 15% fish meal the rest of the protien is made up from poltery and plant sources. the feed conversion ratio of the fish is surprisingly high and at its worst is 1,9kg of feed to make 1 kg of salmon, in the younger fish it is even better than this.

  • Great chain under the video. Are whole fish used in fish food or just pieces (like a hot dog), with the fillets going to market?
    I like buying whole fish from my store, use the rest of it in my garden/compost.