Tuna is a saltwater fish because it is naturally found in the ocean and it is considered to be one of the most highly specialized fishes with regards to its extremely high levels of activity and sustainability. This type of fish is constantly swimming in an effort to counteract their negative buoyancy which helps contribute to how easily they are caught by fishermen.

Tuna is without a doubt one of the most important commercial fish there are and although they are very commonly sold and eaten around the world, they are spread out over all of the different oceans. Yellowfin tuna is perhaps the most important commercial fish and certainly a very common one.