Salmon are one of the only fish that are born in fresh water, spend a large part of their lives in the sea then return to fresh water to spawn.  It is said that they try to return to the exact spot they first wriggled from to lay their own eggs.  They are part of the Salmonidae family of which there are five main species:  chinook, sockeye, coho, pink and chum.  Chinook – also known as King salmon – can grow up to 55kg in weight although the average salmon is between 10-30kg.

Salmon are one of the highest food sources of Omega 3 oils and of course protein, plus they also boast high levels of vitamin D, B6 and B12, niacin, selenium and magnesium.  It is a favourite choice of many chefs around the world, who poach, smoke, fry, grill and BBQ this beautiful pink fish.

Today, most of the wild salmon that comes to the dinner table comes from Alaska and North West Pacific waters, Eastern Canada, Greenland and Norway.  Of all the salmon available, wild Alaskan salmon is revered as the most delectable, since it contains much lower levels of pesticide residues and heavy metals.

Farmed salmon is quite a different story. About 50 per cent of the salmon market is now covered by salmon farms.  Yet the fish that is delivered to dining rooms around the world may not be quite as desirable as we think.  A number of studies have shown that farmed salmon contains alarmingly high levels of pesticides and carotenes (to colour the food) reducing their health benefits to humans. These dioxins and Polychlorinated biphenyls (PCBs) may not have been directly fed to the fish, but have built up in their environment.  PCBs have been banned in the US since the late seventies, yet their effects are still being felt today.  In 2004, the Science Journal released a report recommending that farmed salmon only be eaten once every, possibly every other month, because it had been strongly linked to liver damage, suppression of the immune system, development retardation in children and cancer.  

Scary stuff. We research a number of other publications and discovered that another down-side exists: farmed salmon are now contaminating wild salmon fields.  Since they are intentionally bred to be strong and resilient, it is feared that the invaders could potentially out-compete their wild brothers for food and territory, speeding up their ultimate demise (genetically modified salmon can grow as much as six times faster).  This could have the butterfly effect on the natural balance of our oceans, creating much greater waves then anticipated.  

The US Food and Drug Administration (FDA) commissioned a study into PCB contamination of salmon, concluding that farmed salmon did reach required safety levels of under 2.0ppm.  The study showed that although farmed salmon showed much higher levels than wild salmon and most probably the feed that they are given was responsible for the higher levels, it was still safe to eat.

A number of these studies have called for further investigation into exactly what we are eating and what the effects of these contaminants have on humans and the environment and what the health risk involved are for all concerned.