Quote Originally Posted by hogdog View Post
You are right about the sardines. Sardines are low on the oceanic food chain, and therefore contain low amounts of mercury, PCBs and the other toxins that accumulate in longer-living marine predators such as salmon and tuna. Mackerel is very high in mercury. I dont have the time to elaborate on the negative effects of mercury but just google it and youll see why it would be foolish to feed something high in mercury to working animals when there is a healthier alternative.
Actually, according to this list, North Atlantic/Chub mackerel (which is what I buy) is one of the lowest in mercury also ... so it would be foolish to dismiss mackerel as a staple based on a false belief.

Both of these fish have a high degree of essential nutrients, compared to other meats, both of them have very high Vitamin D content (for healthy bones) ... but mackerel has nearly 8x the amount of Vitamin A that sardines carry ... while sardines have 28x the Omega-6 fatty acid profile as mackerel ... and both are very high in Omega-3 fatty acids. So both of them seem like fine choices.

A knock on both of these fishes is that they're both extremely high in sodium ...

Jack