Game fish typically regulated by fishing seasons include bass, walleye, trout, catfish and salmon in freshwater fisheries and saltwater species such as tarpon, tuna, marlin and swordfish. The length of the season, its timing and other restrictions for the legal catching of specific types of fish vary by state.
Fishing seasons are usually timed to help protect the population and health of a particular type of fish in a specific regional watershed. Many times fishing seasons are closed during the normal time of the fishes' spawning. Some species of fish take several years to reach maturity and only spawn once a year, so protection is needed to help ensure adequate species propagation.