Indian tribes and fishermen Wednesday sued MidAmerican Energy's PacifiCorp over toxic algae allegedly caused by the firm's dams on the Klamath River, while also hoping to win over MidAmerican's biggest shareholder:…Berkshire Hathaway…The lawsuit alleges that the dams…have warmed reservoir waters and created a blue-green algae…that…produces toxins poisonous to wildlife and humans. The levels in recent years "greatly exceed the health-based standards" of…the World Health Organization, the lawsuit alleges. Exposure can cause serious illness and death by liver failure…PacifiCorp spokeswoman Jan Mitchell says the firm does not comment on litigation…