Natal Homing - Bluefin Tuna

Bluefin Tuna

Atlantic bluefin tuna spawn on both the east and west shores of the Atlantic Ocean. When a bluefin tuna hatches, there is a chemical imprint in the animal's otoliths based on the water's chemical properties. Fish born in different regions will show clear differences here. Studies of the commercial fishing industry in the United States show that the population of bluefin tuna in the North Atlantic is made up fish hailing from both coasts. While the fish may live in close proximity out in the Atlantic, they return to their natal region to spawn. Electronic tagging done over several years showed that 95.8 percent of the yearlings tagged in the Mediterranean Sea returned there to spawn. Results for the Gulf of Mexico were 99.3 percent. With the overfishing of this species, scientists have much to learn about their spawning habits in order to sustain the population for both a reliable food source and a healthy ecosystem.