As is typical worldwide of public owned resources, unlimited fishing has led to severe overfishing for some fisheries. In response to this quotas, catch limits, closed and open seasons and other regulations had to be set in place to control the who, when, how and where questions of fishing. In 1851—California enacted a law concerning oysters and oyster beds. In 1852 the first regulation of salmon fishing occurred when fishing weirs or stream fish obstructions were prohibited and closed seasons established. In 1870 California Board of Fish Commissioners, predecessor to the California Department of Fish and Game was established. In 1870 the eastern oyster (Crassostrea virginica) was introduced, in 1871 shad, in 1874 Catfish and in 1879 striped bass were all introduced to California waters. California has about 4,000 lakes and of streams and canals suitable for game fish. To help fish get around dams fish ladders are constructed to allow them to pass on upstream for spawning etc. To preserve, protect and enhance existing fishing the California Department of Fish and Game (DFG) tries to keep all fishing laws enforced. The 720 properties managed by the DFG are: 110 wildlife areas, 130 ecological reserves, 11 marine reserves, 159 public access areas, 21 fish hatcheries and 289 other types of properties. To help keep California waters stocked with fish in 1870 the first California fish hatcheries were built—mostly trout hatcheries. Today (2011) there are eight salmon and steelhead hatcheries and 13 trout hatcheries. Though hatcheries may help some fishing stocks they are no panacea to counteract overfishing, habitat destruction, stream restrictions, water diversions, etc.