"used to consider it a core protein for a healthy diet but now it seems that everyone is recommending to limit consumption because of the mercury."
Actually, some places have started carrying what I call gourmet canned tuna. It is made from smaller sized tuna - the smaller the tuna, the less time it has been alive .. thus the less mercury it contains. My husband works in sportfishing and they have a gourmet can they use for their customers. It isn't available to the general public with the Fish and Game laws regarding the sale of sport caught fish (although my husband is working with the to determine if this still applies after the fish has been processed and cooked).
You'll also find that 'gourmet' cans are better tasting due to being processed differently. Typically, larger canneries (like Chicken of the Sea etc) they will cook the whole fish, then take out the chunks of tuna filet, then recanned it - thus you get fish that is twice cooked and can be dry and tasteless.
In gourmet canneries, their throughput is smaller - so they actually filet the tuna first ... then pack the raw tuna in cans before cooking it. The result is you get your fish canned with the natural fish juices, being much more full of flavor, much more moist, and just better tasting. The smaller canneries also can take the time to add different flavors to the fish (olive oil, jalapeno, dill, garlic are just a few.) My personal favorite is the jalapeno.
Sorry to ramble on. The gourmet is more expensive than the usual stuff - but being low in mercury and better tasting, to me at least, it is worth it.
Oh - and my hubby's cannery has tested their cans to show they are low in mercury.
