Catching fish will reward you with points added to your overall fishing license progress from the fishery you are on.

After earning the required number of points for one of your fishing licenses, it will be automatically leveled up.
At every second level you will gain the ability to draw a random license bonus.

License bonuses are useful, passive bonuses that work all the time. By drawing a correct set of rod bonuses, you will be able to compete at a higher level.
Bonuses only work when catching fish which they were designated for, and excluding the competitive bonus on the fourth slot. Every bonus works for one fish only, and you can only have one fish type bonus drawn against your Fishing License.
Bonuses are divided into rarity groups; rarer bonuses are much more powerful but may require several wheel spins.
The first draw on every level is always free. After that you may try to draw a better bonus, but you will have to pay two pearls for a single draw or 90 for a larger set.

On level 4 of every rod, a Competitive Bonus is drawn. This feature works during duels and when catching fish required in events.
You can also upgrade your Fishing License to PRO so that you can draw a bonus at every level.

A Pro License will let you gain experience points 5 times faster than normal.
You can level up every fishing license to level 12.