Answer: Increase in equilibrium quantity of fish.
Step-by-step explanation: New technology allows fishing boats to catch more fish while using the same number of crew-members. This will increase supply of fish shifting the supply curve for fish to the right.
At the same time a new study shows that eating fish at least three times a week helps prevent heart attacks. This will increase demand for fish shifting the demand curve for fish to the right.
The net effect of these changes is an increase in equilibrium quantity of fish. However, the change in the price of fish cannot be determined as it depends on the magnitude of shift in the two curves.