Water quality testing would be the best approach.
Answer:
Lobsters are adapting to cooler temperatures.
Explanation:
Adaptation may be defined as the phenomena that involves the physical, physiological and chemical changes in the organisms that helps to adapt themselves in their environmental condition.
The adaptation may bring genetic changes in the next generation as well. The lobsters movement per year demonstrates that they are trying to adapt in their environment. The cooler temperatures is favorable for the growth and adaptation of Lobsters.
Thus, the answer is Lobsters are adapting to cooler temperatures.