Column in question, in which he says:
Sure, but worse than that is that the farmed salmon are fed on wild fish. As it takes 2-4kg of fish to make 1kg of salmon, farmed salmon are actually worse for fish stocks than wild salmon are.
And as a BTW, where do pharma companies get the omega-3/fish oil they sell in capsules?
There’s a rather obvious fallacy there.
Like, they would be eating just as much wild fish if they were wild too?
The various international monographs for fish oil used in supplements list as permissible sources:
Anchovy (any species of Engraulidae)
Jack or pompano (any species of Carangidae)
Herring, shad, sardine, or menhaden (any species of Clupeidae)
Smelt (any species of Osmeridae)
Mackerel, tuna, or bonito (any species of Scombridae)
Sand lance (any species of Ammodytidae)
Salmonids (any species of Salmonidae)
These stocks may be fresh or farmed, although some companies market their fish oil as being solely from wild fish. It’s also possible to obtain omega-3 oils from algae; these are marketed as “vegetarian.”
Another problem is that most farmed salmon are pen-raised, in places where they are not native. These pens have a tendency to fail, so now we have Atlantic salmon on the west coast, and we are uncertain about the ecological effects of the addition. Also, even when they are raised in places where they are native, they are often genetically modified organisms. I’m not rabid about genetic modification being a bad thing, but when large numbers of atlantic salmon that are genetically modified to work real well in a fish pen escape and mix with the wild atlantics (which are none too abundant already, and might even be outnumbered by the escapees in some cases), I’m not sure that those genetics will confer desirable characteristics into the wild population. Sorry I have not supplied references. I don’t have them at my fingertips. Anybody really interested and I will provide when I can find time.
My understanding is that fish farms also have a problem with the poor diversity of the gene pool.
That is in a large part because atlantic salmon (the primary kind in net pen aquaculture) are usually genetically modified. The modifications improve their growth rate in aquaculture net farms, but are probably not that great for a wild fish. So when these fish escape and those genes contaminate the wild fish, it might be a bad thing. But no one has ever really studied how bad, I think. Sometimes escaped fish amount to a large part of the population, and that can be bad just from the standpoint of losing natural genetic diversity because these fish come from a smaller number of parents than wild fish. In aquaculture, it is possible to get a much higher survival rate on the young than in the wild, of course, so you don’t necessarily spawn as many adults.
With Pacific salmon, many fish are spawned in hatcheries to supplement the wild fishery, and not grown to harvestable size , and are released at different levels of growth depending on circumstances. (although some of these fish, most of the ones that survive to spawning, return to the hatcheries where they were produced, and are harvested there, in part to get the eggs for the next batch of fish). Many of those carcasses are taken up to where the fish would have spawned if there were natural runs, and thrown in the water to decompose there. )By that time, they are not great eating anyway) The idea is to recreate this natural source of nutrients that run the stream productivity. In the past, there has been a problem with genetic diversity from this process, because the only spawned enough fish to produce the number of young they needed. Now, however, they are more careful to maintain the genetic diversity and arguably they are taking care of that problem by spawning more fish. There are studies that are done that indicate how many fish need to be spawned to maintain the diversity. I’m not up enough on the current debate to know how well that problem has been taken care of.
I forget if it was mentioned before, but other problems with salmon net pen aquaculture are 1) the amount of poop and uneaten food that ends up in the area, causing problems similar to those you’d expect from a sewage effluent, and 2) antibiotics and therapeutics added to the water and food, which end up in the environment. In the case of the antibiotics, it is a problem of generation of resistant bacteria.
Care to elucidate? It’s obviously not obvious to me, or I wouldn’t have posted it, would I?
Perhaps I missed it, but I see nothing on that site to say what their fish food is made from.
What Czarcasm said. Unless of course salmon in the wild have a more vegetarian diet than in pens, they will be eating just as much wild fish outside the pens as inside. Perhaps even more, if the farmed salmon are genetically modified to need less food to grow and/or they get less exercise from lack of long distance swims and so don’t expend as many calories not growing as they would have in the wild.
Wild salmon is “only” a danger to the populations of wild salmon. Catch them all, and that’s the end of one population or species.
Farmed salmon is a danger to any species suitable for salmon fodder. Catch them all, and that’s the end of one species, and then you can go on to the next.
Now this is the most extreme view, but even if one supposes perfect fishery policies that prevent collapses in any fish population, farmed salmon still has the potential to be, and currently is, environmentally unfriendly. Farmed salmon isn’t only fed on species and sizes that wild salmon would catch and eat, they’re fed whatever is available, cheap and of sufficient quality. This includes high end ocean predators like mackerel, which wouldn’t be a staple in wild salmon diet, and thus puts farmed salmon higher in the food chain than wild. The nutritional value of a species like mackerel is as high as that of farmed salmon, but the price/demand is much lower, so economically it makes sense to turn it into salmon fodder instead of people fodder, although the latter would be the environmentally better choice.
I looked into this and most of the fish used in fish meal is are small plankton feeders, although larger individuals eat some fish, and the Chilean Jack Mackerel is more of a piscivore than most of the rest. http://assets.panda.org/downloads/foodforthoug.pdf This does not talk about the primary fish made into fish meal in the USA, the menhaden, which is also a small clupeid that eats mostly zooplankton, and would be considered a prey fish. I don’t mean to say that harvesting all these fish and using them as fish meal is the smartest thing to do, or that harvesting all these prey fish has no up-the-food-chain effects on wild predators. Just that the fish that are being turned into fish meal WOULD be fish that wild salmon or other predator fish would be likely to eat, and that other large predators are not turned into fish meal substantially.
There is a substantial effort to find vegetable substitutes for fish meal - “fish meal substitutes” will turn up a plethora of studies, and the amount of fish meal in fish feeds has been decreasing dramatically, as a result of these new feeds. Also, there are efforts to turn offal from fish processing into fish meal, which has had substantial success, and there have been some efforts to turn invasive species (Asian carps) into fish meal, which has not had substantial success so far.
Still, more fish is captured for fish meal than for direct consumption by humans.