If the fishing is in control, fine...but trawlers drag anything from the sea in their nets and around 10-20% of the stuff is what they were looking for. Places like Africa is hit hard cause there is no money for naval patrols and these trawlers know it.
They stay in international waters during the day and go more inshore in the evening!
A lot of abolone you see in Asia is illegal from places like South Afica...(these are normally from sindicates working with people in the country)