Mackerel is an important food fish that is consumed worldwide. As an oily fish, it is a rich source of omega-3 fatty acids. It is also very bold in flavor. If you're wondering what does mackerel taste like, it is similar to a tuna. Mackerel also tastes slightly similar to salmon, especially when it is fresh. Compared to other fishes, mackerel also has a sweet taste. This fish has a decent amount of bones, and it is not overly salty.