According to the California Department of Fish and Wildlife, a fishing license is a requisite for any individual who would like to take fish and other creatures found in ocean waters or inland. In addition, there are report cards needed for particular areas and species.
In case that you are exempted to possess a sport fishing license, you are still required to present the right report card while you are fishing. You also need to make sure you, follow the laws on fishing in the state you are living in.
In many places, there are laws regarding too small of a fish or even the quantity of how many fish you are allowed to catch.