The experiment with caged bluefin tuna is to help arrest the decline in their populations.
The project led by Prof Chris Bridges includes experts for Israel, Greece and Malta is implanting the hormones in fish in cages of the Italian coast - part of an Italian project led by the University of Bari.
The project expects to spawn 10 million young fish in the Mare Nostro fish Farm in Vibo Marina.
The young fish are then being distributed across Europe to institutes in France, Spain, Crete and Israel to be raised into mature fish.