San Francisco Bay is becoming less opaque as the sediments power-washed into the Estuary by miners so long ago gradually disperse. This lets sunlight penetrate deeper into the water, creating more favorable conditions for the kind of problematic algal blooms that can shut down crab fisheries and keep people and their pooches out of the water. Scientists have collaborated on some new computer models, however, that may help them predict where and when nutrients, like nitrogen and phosphate from discharges and runoff, may exacerbate the situation.