Introduction of predatory fish species such as bluegill and various types of bass that prey on salmon smolt are also a major contributor to the decline. The San Joaquin's point of divergence with the distributary Old River has historically created a sort of bottleneck for out migrating salmon because the Old River in turn branches into many side-channels and sloughs of the delta as well as various canal intakes. Recent years have seen work by the California Department of Water Resources and the California Department of Fish and Game to construct and manage temporary rock barriers at the head of the Old River in order to keep fish in the main channel of the San Joaquin River. In the fall of 2009, just 2,236 salmon returned to the entire river system to spawn; this has led to a government ban on salmon fishing off the coasts of northern California and Oregon. Recent years have seen efforts to bring back some of the salmon population to the San Joaquin and some of its tributaries; these include the establishment of fish hatcheries. , plans had been finalized for a $14.5 million hatchery near Friant Dam as part of a $20 million federal restoration project for the fish.