Final answer:
In a very dry season, the Christmas Island crab population would likely be negatively impacted due to limited water availability and decreased food sources.
Step-by-step explanation:
In a very dry season, the impact on the Christmas Island crab population would likely be negative. Crabs are dependent on the wet season for the successful reproduction and survival of their offspring. During dry seasons, the availability of water decreases, which limits the crabs' ability to reproduce and thrive. Additionally, the lack of rainfall can lead to a decrease in food sources for the crabs, further impacting their population.