Why would one need to know when a game fish is breeding? Would one want to get pregnant fish for the eggs as a delicacy or in the case of something like salmon,

Why would one need to know when a game fish is breeding? Would one want to get pregnant fish for the eggs as a delicacy or in the case of something like salmon, for whatever reason, specialize in or avoid them after they have metamorphosized for the breeding process? For the land animals would it be to have easier hunts during that time or shortly afterwards?