Overfishing is one of the main problems with many marine fisheries with about 30% of all marine fisheries thought to be over fished. Inadequate data is one of the main restrictions to finding and instituting reasonable and sustainable limits on many fishing stocks. To control overfishing NOAA has instituted the National Marine Fisheries Service (NMFS) to set quotas, specify open and closed fisheries and seasons and other limits on what, when and how fish are caught within federal guidelines. With the help of the six regional science centers, eight regional fisheries management councils, the coastal states and territories, and three interstate fisheries management commissions, These councils have had varying amounts of success, but seem to at least have started the rehabilitation of some fisheries. United States Fish and Wildlife Service National Fish Passage Program tries to remove barriers blocking the natural migration of fish to historic habitat used for reproduction and growth.