Add the tomatoes, shrimp, fish, and bay leaf, and stir. Add the rice, stir gently, and add the water. Gently move a spoon across the bottom of the pot, making sure that the rice is not sticking. Bring to a boil, then reduce the heat, cover, and simmer for about 15 minutes or until the rice has absorbed most of the liquid. Turn off the heat, then fold in the oysters, cover, and let sit for about 8 minutes, during which time the jambalaya will continue cooking from residual heat.