Complex sentence: However, there have been laws and regulations set up to protect the fish population so on a daily basis, one can catch only 20 fish in combination of all other species, with not more than 10 fish of one species.
Split into simpler sentences: However, there have been laws and regulations set up to protect the fish population. On a daily basis, one can catch only 20 fish in combination of all other species, with not more than 10 fish of one species.