Around the turn of the century, there were only 25 bison in Yellowstone, as open-access poaching nearly wiped out the entire herd. Fortunately, private individuals such as William Hornaday, founder of the American Bison Association, ensured that the majestic buffalo survived. Hornaday and others saw to it that bison were bred, fed, and protected from hunters. The recovery of the American bison is a testament to the power of private conservation. Were it not for the care that private owners had for the bison, it is possible that the symbol of the Buffalo Bills would be just a memory.
Owners protect their resources because they receive the benefits of that protection.
In the commons, however, there is no incentive to protect a resource because you cannot be sure that you will receive the benefit. Unlike the commons, ownership encourages stewardship. If you own something, you have an interest in ensuring that it is protected and that its value is maintained. They also invest in local ecological restoration and protection to ensure that they have oysters in the future. Not only must landowners take care in their own actions, in many cases they must defend their land against the intrusions of others.