(AP) — In this Dec. 6, 2011, file, photo, owner Kevin Lunny holds a Pacific oyster at the Drake's Bay Oyster Co. in Point Reyes National Seashore, Calif.
Scientists blame higher levels of carbon dioxide in Pacific Ocean waters caused by man-made global warming for the failure of oysters to produce young at an Oregon hatchery. (AP Photo/Eric Risberg, File)