I do not eat fish as often as I used to due to high mercury levels, but I still believe everything is okay in moderation. When I do, I make sure the fish is wild and line caught. Did you know you are entitled to sniff the fish for freshness before buying it? It should smell like the sea, not strong and fishy, if it is really fresh. While the color of raw Ahi tuna is red, it actually has a very mild flavor.