Answer:
Drastic weather changes.
Step-by-step explanation:
Meritt island national wildlife refuge is a U.S national wildlife refuge, located at the atlantic coast of florida's and it also a largest barrier island.
According to this, the major ecological threat of the meritt island national wildlife refuge is drastic weather changes, states that the amount of water vapour in the atmosphere has increased due to human activity caused warming, this results in heavy rainfall. It also affects the weather pattern and the storm. A more water vapour is evaporated in the atmosphere, then it becomes fuel to develop more powerful storm.