Many marine sanctuaries allow for industrial fishing, and even bottom trawling, which can severely damage the seafloor and catch all kinds of critters that are not targeted by the fishing operation (ie., bycatch). Sanctuaries often allow these activities to continue even after research shows they’re damaging marine habitats.
“Is bottom trawling really compatible with the primary objective of resource protection? I would say probably not,” said Priscilla Brooks, director of ocean conservation at the Conservation Law Foundation. “Many sanctuaries are really sanctuaries in name only.”