Wild salmon is a healthier choice than farmed salmon, which has been found to contain high antibiotic, PCB and dioxin levels. A source of omega-3 fatty acids and astaxanthin, wild salmon oil has a naturally occurring ratio of EPA to DHA. Wild salmon may be a better environmental choice because salmon farms can pollute coastal waters. The oil is extracted from already harvested salmon, using fish parts that would otherwise be wasted, thereby conserving existing stocks.