Describe an example of how a single topic can involve multiple fields of science?

An example of a single topic involving multiple fields of science would be, say, Fish Hatchery Management. Yes, it's aquaculture, but before one could get into that field of work, one would have to go through some different science classes, like Biology, Agronomy, Agricultural Science, and probably more. All of these types of sciences would all go into that one topic: Fish Hatchery Management (Which makes about $14,370 per year, so don't turn it down just yet - ha ha!), in the Aquaculture category.