freezing tuna?

[FF_T_Warren]

Ok guys I got a question about saving/freezing tuna. a friend of mine in august gave me some tuna that he didn't have room for. It was a pretty good bit, so I put it in the food saver and vacuum sealed it. Well it already is nasty to the point of its not any good to eat. It is extremely fishy tasting. It started getting nasty probably back around december and now its to the point that its unedible unless you starving. I mean is this normal for tuna to only stay good for 3-4 months. I mean we have trout in the freezer that taste just fine and its a few months older than the tuna.

Is this normal and how do yall find it best to freeze it?