Through the years, the chinook, or king, salmon that pass through San Francisco Bay have suffered from diversions of freshwater to cities and farms, the operation of the water-export pumps that send delta water to other regions, exposure to pollutants and warming ocean conditions. Grader, along with representatives of most sport and environmental groups, attribute the salmon decline primarily to Central Valley dams that flood or block spawning grounds and the delta water pumps that move water around the state. A federal law was passed in 1988 to reserve water to help fish, but the water only makes it as far as the delta - not out to the bay, where it would help migrating fish like salmon, he said. The popular chinook salmon is the most recent of the fish that feed in the rivers, delta and the bay to suffer a loss in numbers, said Tina Swanson, senior scientist at the Bay Institute, an environmental group. read more