One of the state’s best investigators was on the hunt for golden mussels — a dangerous new invader in California’s waters, with a reputation for destruction.  Wearing a collar and a tongue-lolling grin, Allee, a Belgian Malinois, sniffed along the glittering hull of a bass boat at an inspection station in Butte County. … The dog was searching for any hint of the thimble-sized mussels hidden in the nooks and crannies of boats headed to Lake Oroville, the state’s second-largest reservoir, or two smaller reservoirs nearby. … State water managers made the alarming discovery last October that golden mussels, which are native to China and Southeast Asia, had invaded the Sacramento-San Joaquin River Delta —  the core of California’s massive water delivery systems. … Now the mussels are here to stay. They cannot be eradicated. Water suppliers bracing for the onslaught have instead turned their efforts to shoring up pipes, pumps and treatment plants against the infestation.