In Connell's "The Most Dangerous Game," how does Zaroff stock his island with game?

When Rainsford and General Zaroff are speaking about different types of game, Rainsford says that he has heard that the most dangerous game is Cape buffalo. General Zaroff says the following:

"No. You are wrong, sir. The Cape buffalo is not the most dangerous big game . . . Here in my preserve on this island . . . I hunt the most dangerous game."

Surprised, Rainsford asks what is on the island, and Zaroff says, "Oh, it isn't here naturally, of course. I have to stock the island." Rainsford asks his host what type of animals he has on the island, but Zaroff refrains from explicitly saying what he stocks for awhile. After a long story about his hunting life, Zaroff finally gives Rainsford enough clues to suggest that he hunts men. Once the answer is out, Zaroff explains that he only hunts "the scum of the earth--sailors from tramp ships." To further explain how he stocks his island, General Zaroff says the following:

"This island is called Ship-Trap . . . Sometimes an angry god of the high seas sends them to me. Sometimes, when Providence is not so kind, I help Providence a bit. Come to the window."

Then, General Zaroff shows Rainsford that from a push of a button at his window he can control lights on the island that signal boats towards an imaginary channel. When boats head for the channel, they actually run into "giant rocks with razor edges . . . [that] can crush a ship as easily" as a nut. The whole island is a trap for luring ships in so they will wreck. As a result, men who make it to the island are placed in Zaroff's "training school" where they will eventually be hunted when they are ready to play the game. Therefore, Zaroff says that sometimes Providence leads his quarry to his island; and other times, he gets his men from shipwrecks that he purposefully creates using his "harbor" lights.