Trapped in the lake were and still are, sharks, swordfish and other ocean fish - the only freshwater lake with oceanic animal life!The 'juice' in canned salmon comes from the fish itself, whereas tuna has oil or water added in the canning process.25 years ago large Atlantic bluefin tuna (250 to over 1,000 pounds) might sell for a penny a pound for catfood, if it sold at all.