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Science Matters by David Suzuki
A massive new scientific study that found high contamination levels in farmed
salmon made headlines last week, but the results shouldn’t really be surprising.
Applying industrial production methods to raising food animals has caused problems
at every turn.
Both beef production and salmon farming have been in the news recently - and not
in a favourable light. According to a study published in the journal Science,
farmed salmon contains up to 10 times as much contaminants such as PCBs and dioxin
as do wild salmon. Many of these contaminants are believed to be cancer-causing
agents. In fact, contamination levels are high enough that the report authors
recommend people eat no more than one serving of farmed salmon per month.
The salmon farming industry had criticized a previous study that found similar
contamination levels because it used a small sample size. This time, researchers
tested some 700 fish, totaling more than two tons, from markets and wholesalers
all over the world, including Vancouver and Toronto. They consistently found high
levels of contaminants in farmed fish.
The source of the contamination is likely the food fed to farmed salmon. Salmon
chow is made from other, less profitable fish, from all over the world. This fish
is then ground up and made into fishmeal. The problem is that organic contaminants
like PCBs "bioaccumulate" in the food chain through animal fat. This
means that, as one fish eats another, the contaminant concentrations get higher
and higher. All wild fish, including salmon, suffer from this problem, but farmed
fish fare the worst, likely because concentrating fish into meal accentuates the
bioaccumulation process.
Proponents of fish farms will likely regard this as a minor setback for a growing
industry. But salmon farming faces a host of other problems, from site pollution
to sustainability issues. Right now, three to four kilograms of wild fish are
needed to be ground up into food to produce one kilogram of farmed salmon. So,
we are depleting wild fish stocks to produce contaminated fish.
Beef production has also been in the news again due to the discovery of another
case of BSE or, mad cow disease, in North America. While the risk to humans is
relatively low, the incident again exposes the problems associated with mass-producing
meat with a focus on profits rather than human or animal health and welfare. BSE
would likely have never been a problem if factory farms did not try to increase
the growth rate of cattle and therefore, profits, by feeding them meat products,
including other cattle, essentially turning herbivores into carnivores.
Factory farming, whether it’s for pork, beef, chicken or salmon, treats
animals like raw materials that are processed and turned into an end product -
meat. Animals in these systems are literally treated like inert matter. Little
thought is given to their welfare. They are crammed into small spaces, sometimes
by the thousands, and fed antibiotics to increase growth rates and reduce infections.
Salmon farms use pesticides to kill off parasites. Hog farms create so much waste
that they pollute surrounding groundwater, rivers and ocean shorelines.
By trying to force industrial factory-style processes that focus entirely on profit
and efficiency onto agriculture, we’ve created huge problems for ourselves.
Is it really worth jeopardizing human health, polluting our water and depleting
our ocean fish stocks just to have 99-cent hamburgers, cheap pork rinds and fresh
salmon year round? It’s time to take a good hard look at our priorities
and consider more than profits in the way we produce meat.
Take
the Nature Challenge and learn more at www.davidsuzuki.org
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