Salmon fishermen on the West Coast of the United States are expressing increasing concern about threats to the fish population. Heat waves and drought, a long period without rain, are raising water temperatures and lowering water levels. The extreme conditions are killing wild fish from Idaho to California. Hundreds of thousands of young salmon are dying in Northern California’s Klamath River. The low water levels fuel the spread of parasites that kill the fish. A collapse of one year’s group of young salmon can have lasting effects on the total population. It can also shorten or stop the fishing season. Climate change is making the American West hotter and drier. and endangering the salmon fishing industry. The industry is worth about $1.4 billion dollars in California alone. The falling numbers of wild salmon catches has caused a sharp rise in price for the fish. Fisherman Mike Hudson says people are not able to spend $35 for a pound, about 450 grams, of the fish. Hudson has been catching and selling salmon at farmers markets in Berkeley for 25 years. Hudson has considered retiring and selling his 12-meter boat because business, in his words, is “going to get worse from here.” Winter-run Chinook salmon are born in the Sacramento River and travel hundreds of miles to the Pacific Ocean. There, they normally spend three years before returning to their birthplace to mate and lay their eggs between April and August. Unlike the autumn-run Chinook that survives almost entirely from hatchery breeding programs, the winter-run is still largely wild. Federal fisheries officials predicted in May that more than 80 percent of baby salmon could die because of warmer water in the Sacramento River. Now, state officials say that number could be higher because of a quickly drying cool water in Lake Shasta. The lake is California’s largest reservoir. It is filled to only about 35 percent capacity, federal water managers said this week. “The pain we’re going to feel is a few years from now,” said John McManus. The executive director of the Golden State Salmon Association, which represents the fishing industry, said that soon there will be no wild, naturally bred salmon in the ocean.